Category Archives: Diet, Habits, & Other Behaviors

The Benefits of Exercise After Getting Cancer

Breast Cancer, Colon Cancer, Diet, Habits, & Other Behaviors, General Treatment Issues, Prevention, Quality Of LIfe, Treatment & Management

Farmin Shahabuddin, MPH, Morgan Wharton and Annika Schmid, Cancer Prevention and Treatment Fund

You may have heard that regular exercise can reduce your risk of developing cancer, but did you know it’s also good for cancer patients who are undergoing or have completed treatment?

Is Exercise Good for Everyone with Cancer?

Exercise has proven benefits for cancer patients, ranging from improved fitness and higher quality of life to reduced rates of recurrence and a longer life. What we know about exercise and cancer mostly comes from studying patients with breast or colon cancer, but there is now evidence that there are benefits of exercise for men and women suffering from almost all types of cancer, even cancer as advanced as Stage III. [1, 2]

The best news of all: It doesn’t matter if you were fit before you got diagnosed.[1, 3, 4] A 2026 study found the following finding: lung and rectal cancer survivors who were inactive before their diagnosis but became active enough to meet physical activity guidelines afterward were still 42% and 49% less likely to die from their cancer, respectively, compared to those who remained inactive both before and after diagnosis.[5] So, it’s never too late to start exercising to fight cancer. If you’re coping with cancer or its aftermath, now is the time.

How Does Exercise Help Cancer Patients?

Many studies have shown that exercise is beneficial to cancer patients, but no one is sure exactly why. Earlier studies suggested that exercise may help women avoid breast cancer or a recurrence of it by decreasing female hormones that feed cancer in the breast [6,7] or by lowering inflammation in the body [8] , a suspected contributor to many diseases.

Physical Benefits of Exercise for Cancer Patients

Studies have shown that in cancer patients, exercise during or after treatment reduces fat and improves body mass index (BMI). [9, 10] Exercise lowers blood pressure, boosts the immune system, and increases bone mineral density. [10, 11] Denser bones mean fewer fractures.

Not surprisingly, cancer patients who exercise regularly during and after treatment reported increases in strength, walking ability, aerobic capacity, and flexibility. [9, 10]

Cancer patients who had completed treatment reported fewer negative side effects from treatment once they began to exercise regularly.[2] Patients who exercised during treatment reported less nausea and less difficulty sleeping.[10] The most reported improvement was reduced fatigue. [4, 10, 11]

A study published in 2021 indicates that exercise may also help relieve “chemo brain” (also known as chemo fog), which is a common side effect for cancer patients undergoing chemotherapy.[12] Common symptoms of chemo brain are having trouble with learning new tasks, remembering names, paying attention, and concentrating. The study found that patients who did either 2.5–5 hours of moderate intensity exercise (like brisk walking) per week or who did 1.5–2.5 hours of high intensity exercise (such as running) per week in the week before starting chemotherapy, within 1 month of completing chemotherapy, and 6 months after completing chemotherapy were less likely to report “chemo brain” symptoms than patients who did not exercise. Chemo brain can be upsetting and debilitating, affecting more than 75% of breast cancer patients undergoing chemotherapy, for example.

Mental and Emotional Benefits

In addition to the physical health benefits of exercise, cancer patients who exercised also reported improved mental and emotional well-being.[9] Patients who exercised during treatment and those who began to exercise afterwards frequently reported an increase in quality of life, less anxiety, and a renewed “fighting spirit.”[10] Cancer patients over the age of 80 who exercised regularly during their weeks or months of treatment reported less loss of memory.[13]

Long-Term Survival and Reducing Cancer Recurrence

Because exercise improves the immune system, cancer patients who exercise regularly lower their risk of the cancer returning. [1, 9, 11, 14] Patients who exercise are less likely to die from cancer and are more likely to live longer than patients who don’t exercise.

A large 2026 study combining data from six major long-term research projects followed more than 17,000 cancer survivors for an average of nearly 11 years after diagnosis to examine the survival benefits of moderate to vigorous physical activity. The activities included brisk walking, cycling, or swimming, and the patients had been diagnosed with bladder, endometrial, lung, oral cavity, ovarian, or rectal cancer. Current guidelines suggest that people with a history of cancer should aim for 150 to 300 minutes of moderate intensity or 75 to 150 minutes of vigorous intensity aerobic physical activity per week.[5]

The study found that even less than the standard recommended guidelines of physical activity seemed beneficial. For example, bladder cancer survivors who exercised were 33% less likely to die from their cancer, endometrial cancer survivors were 38% less likely, and lung cancer survivors were 44% less likely, compared to those who did no physical activity. Oral and rectal cancer survivors who doubled the amount of activity that was in the recommended guidelines were 61% less likely to die of oral cancer and 43% less likely to die of rectal cancer.[5]

A 2022 study found that cancer survivors who exercise and do not sit 8 or more hours a day live longer than less active cancer survivors.[15] The study followed over 1,500 cancer survivors ages 40 and over for an average of 4.5 years. The researchers found that those who exercised at least 150 minutes per week were less likely to die (of cancer or anything else) than people who did not report exercising. Survivors who reported sitting for more than 8 hours a day were also more likely to die than those who reported sitting less than 4 hours per day, and survivors who reported both a lack of exercise and sitting more than 8 hours per day were the most likely to die of all the survivors studied.

A 2020 study of 8,002 Black and white adults aged 45 and older in the U.S. examined whether sitting for long periods of time increases the chances of dying from cancer.[16] Each participant wore a hip-mounted device, like a fitness tracker, for 7 consecutive days to measure how much time they spent sitting versus being physically active. Over an average follow-up of about 5 years, 268 participants died of cancer. People who spent the most time sitting were more likely to die from cancer compared to those who sat the least. People who replaced just 30 minutes of sitting per day with moderate to vigorous physical activity had a 31% lower chance of cancer death. In fact, people who swapped that sitting time for light activity like standing or gentle walking were 8% less likely to die. This shows that the total amount of time spent sitting matters in addition to the time spent exercising, so cancer survivors should try to sit less and move more throughout the day.

What Kind of Exercise Should I Do?

Aerobic activity of light to moderate intensity was the most common type of exercise in the studies of cancer patients. [1, 9] Combining aerobic exercise with walking and resistance training (such as weightlifting or using resistance bands) led to greater health benefits than aerobic activity alone. [9, 11]

Walking can improve the health of cancer patients. Studies estimate that the greatest benefit from walking is seen in patients who walk at an average speed (a 20-minute mile) for 3–5 hours weekly.[2] Patients who walked just 1 hour per week, regardless of walking speed, showed improvements over the group of patients who reported no physical activity in a week.

To get the most out of exercise, you need to make it a habit—something you commit to for the long-term. That’s why it is better to start small, with easily achievable changes like using the stairs regularly instead of the elevator or walking each evening after dinner. Remember to set realistic goals, because it is better to start small and keep it up than to try to do too much and give up. Don’t miss the chance to get at least some benefit from this easy, free strategy to fight cancer.

The Bottom Line

Exercise helps individuals who are undergoing cancer treatment and those who have completed cancer treatment. Cancer patients who exercise regularly during and after treatment can expect fewer side effects from treatment, including less fatigue, fewer problems with concentration and memory, and better overall fitness and health. Patients who exercise are less likely to experience a return of cancer in the future and are more likely to live longer, healthier lives.

You should try to walk at least 3 to 5 hours a week at an average pace (about 1 mile per 20 minutes). Even minimum exercise, like walking one hour per week, can improve the health of cancer patients who have completed treatment, compared to cancer patients who do not exercise at all. The benefits from exercise can be seen in all cancer patients regardless of whether they exercised regularly before they were diagnosed with cancer. It’s never too late to begin to exercise and improve your health!

References

  1. Jeffrey A. Meyerhardt, D.H., Donna Niedzwiecki, Donna Hollis, Leonard B. Satz, Robert J. Mayer, James Thomas, Heidi Nelson, Renaud Whittom, Alexander Hantel, Richard L. Schilsky, and Charles S. Fuchs, Impact of physical activity on cancer recurrence and survival in patients with stage III colon cancer: Findings from CALGB 89803. Journal of Clinical Oncology, 2006. 24(22): p. 3635-3541.
  2. Michelle D. Holmes, W.Y.C., Diane Fesknich, Candyce H. Kroenke, Graham A. Colditz, Physical activity and survival after breast cancer diagnosis. Journal of the American Medical Association, 2005. 293(20): p. 2479-2486.
  3. Jeffrey A. Meyerhardt, E.L.G., Michelle D. Holmes, Andrew T. Chan, Jennifer A. Chan, Graham A. Colditz, and Charles S. Fuchs, Physical activity and survival after colorectal cancer diagnosis. Journal of Clinical Oncology, 2006. 24(22): p. 3527-3534.
  4. Margaret L. McNeely, K.L.C., Brian H. Rowe, Terry P. Klassen, John R. Mackey, Kerry S. Courneya, Effects of exercise on breast cancer patients and survivors: A systematic review and meta analysis. Canadian Medical Association Journal, 2006. 175(1): p. 34-41.
  5. Rees-Punia E, Teras LR, Newton CC, et al. Leisure-Time Physical Activity and Cancer Mortality Among Cancer Survivors. JAMA Netw Open. 2026;9(2):e2556971. doi:10.1001/jamanetworkopen.2025.56971
  6. Key T, Appleby P, Barnes I, Reeves G. Endogenous sex hormones and breast cancer in postmenopausal women: reanalysis of nine prospective studies. J Natl Cancer Inst. Apr 17 2002;94(8):606-616.
  7. McTiernan A, Tworoger SS, Ulrich CM, et al. Effect of exercise on serum estrogens in postmenopausal women: a 12-month randomized clinical trial. Cancer Res. Apr 15 2004;64(8):2923-2928.
  8. Friedenreich CM, Neilson HK, Woolcott CG, et al. Inflammatory Marker Changes in a Yearlong Randomized Exercise Intervention Trial among Postmenopausal Women. Cancer Prevention Research. January 1, 2012 2012;5(1):98-108.
  9. Daniel Y T Fong, J.W.C.H., Bryant P H Hui, Antoinette M Lee, Duncan J Macfarlane, Sharron S K Leung, Ester Cerin, Wynnie Y Y Chan, Ivy P F Leung, Sharon H S Lam, Aliki J Taylor, Kar-keung Cheng, Physical activity for cancer survivors: Meta analysis of randomised controlled trials. British Medical Journal, 2012. 344(70).
  10. Ruud Knols, N.K.A., Daniel Uebelhart, Jaap Fransen, and Geert Aufdemkampe, Physical exercise in cancer patients during and after medical treatment: A systematic review of randomized and controlled clinical trials. Journal of Clinical Oncology, 2005. 23(16): p. 3830-3842.
  11. Rosalind R. Spence, K.C.H., Wendy J. Brown, Exercise and cancer rehabilitation: A systematic review. Cancer Treatment Reviews, 2009. 36: p. 185-194.
  12. Elizabeth A. Salerno, Eva Culakova, Amber S. Kleckner, Charles E. Heckler, Po-Ju Lin, Charles E Matthews, Alison Conlin, Lora Weiselberg, Jerry Mitchell, Karen M. Mustian, Michelle C. Janelsins. Physical Activity Patterns and Relationships With Cognitive Function in Patients With Breast Cancer Before, During, and After Chemotherapy in a Prospective, Nationwide Study. Journal of Clinical Oncology. 2021. https://ascopubs.org/doi/full/10.1200/JCO.20.03514.
  13. LK Sprod, S.M., W Demark-Wahnefried, MC Janelsins, LJ Peppone, GR Morrow, R Lord, H Gross, KM Mustian, Exercise and cancer treatment symptoms in 408 newly diagnosed older cancer patients. Journal of Geriatric Oncology, 2012. 3(2): p. 90-97.
  14. Barbara Sternfeld, E.W., Charles P. Quesenberry, Jr., Adrienne L. Castillo, Marilyn Kwan, Martha L. Slattery, and Bette J. Caan, Physical activity and risk of recurrence and mortality in breast cancer survivors: Findings from the LACE study. Cancer Epidemiology, Biomarkers & Prevention, 2009. 18(1): p. 87-95.
  15. Cao, C, Friedenreich, CM and Yang L. Association of Daily Sitting Time and Leisure-Time Physical Activity With Survival Among US Cancer Survivors. JAMA Oncology, January 6, 2022 online, https://jamanetwork.com/journals/jamaoncology/article-abstract/2787951.
  16. Gilchrist SC, Howard VJ, Akinyemiju T, Judd SE, Cushman M, Hooker SP, Diaz KM. Association of Sedentary Behavior With Cancer Mortality in Middle-aged and Older US Adults. JAMA Oncology. 2020;6(8):1210–1217.

Antioxidants and cancer risk: the good, the bad, and the unknown

Diet, Habits, & Other Behaviors
By Nyedra W. Booker, PharmD, MPH and Diana Zuckerman, PhD
Updated 2015

Do you take vitamin pills or dietary supplements? If so, you are not alone! Most adults in the U.S. take at least one dietary supplement,1 and products with claims of cancer and other disease-fighting benefits are increasingly popular. Vitamins A, C, E, beta carotene and selenium are all considered “antioxidants,” and people take them hoping to prevent disease and improve overall health.  You have probably heard that antioxidants fight cancer, but the latest research suggests that any benefits they have in preventing cancer may be reversed for people who already have cancer (including those who have cancer but haven’t been diagnosed yet).

What are antioxidants?

Antioxidants prevent a chemical process known as “oxidation,” which is a natural part of living and aging. Oxidation damages cells and can lead to the development of disease, including Alzheimer’s, heart disease, and cancer. Antioxidants are found in fruits, vegetables, nuts, beans, grain cereals, and other foods. Even dark chocolate is rich in antioxidants.

The antioxidants made by our body play an important role in finding and repairing damaged cells, as well as boosting our immune system. But do antioxidants in dietary supplements provide the same health benefits as the antioxidants we make on our own? Supplements are often produced using man-made products or by extracting the antioxidants from certain foods. Unfortunately much of the health benefits may be lost during these manufacturing processes.2

The good, the bad and the unknown

A landmark study from the late 1980s was among the first to look at the effect of antioxidants on cancer risk. The study involved almost 30,000 Chinese men and women at high risk for cancer who took daily vitamin and mineral supplements for 5 years. Patients were assigned to receive one of the following combinations of supplements:  (a) retinol and zinc, (b) riboflavin and niacin, (c) vitamin C and molybdenum, or (d) beta carotene, vitamin E and selenium. Men and women taking the antioxidant combination of beta carotene, vitamin E and selenium had significantly lower death rates and a reduced risk for cancer after 1-2 years of taking the supplements.3

However, excitement about antioxidants to prevent cancer was short-lived. In 1994, the New England Journal of Medicine (NEJM) published findings from an 8-year study on antioxidant use to prevent lung cancer in men who smoke. Almost 30,000 male smokers age 50-69 were randomly assigned to one of the following: (a) vitamin E, (b) vitamin E + beta carotene, (c) beta carotene or (d) placebo (a sugar pill).  But rather than reduce the risk for lung cancer, the men taking beta carotene (either alone or in combination with vitamin E) were more likely to develop lung cancer after only 18 months of daily beta carotene use, and the number of lung cancer cases continued to increase disproportionately for the duration of the study.4

In 1996, a study of more than 18,000 men and women at high-risk for lung cancer looked at whether antioxidants could reduce the risk of lung cancer in high-risk patients. Study participants included current smokers, former smokers, and workers with prior exposure to asbestos, who were randomized to receive beta carotene, vitamin A or placebo.  The study was stopped early when preliminary results showed a 17% higher death rate in the antioxidant groups.5

These two lung cancer studies caused great concern about antioxidants.  Beta carotene was discontinued two years into a study involving 540 patients with head and neck cancer taking a combination of vitamin E + beta carotene supplements to prevent a second cancer. But the researchers found a significant increase in the risk of a second cancer in the patients who continued to take vitamin E. Once this supplement was discontinued, the cancer risk decreased to that of patients taking the placebo.6

A 2012 review of almost 80 randomized clinical studies of antioxidant use (vitamin A, C, E, beta-carotene and selenium) again showed cause for concerns. Together the studies included a total of almost 300,000 men and women (described as both “healthy” and with diseases in a “stable phase”). Men and women were more likely to die if they were taking Vitamin E, beta-carotene or doses of vitamin A that exceed the Recommended Dietary Allowance (700µg for women and 900µg for men). The authors concluded that the use of antioxidant supplements could be dangerous for the general population and those diagnosed with various diseases.7

What could explain the possible increased cancer risk?

Starting around 2008, there was growing evidence that antioxidants could be dangerous for anyone who already had cancer, and that could explain some of the contradictory results of previous studies. In one study, large doses of vitamin C supplements reduced the effectiveness of several anti-cancer drugs including Methotrexate, Doxorubicin and Imatinib, resulting in 30-70% fewer cancer cells killed. The authors concluded that vitamin C may actually be helping cancer cells survive by protecting the cells’ power source.8 In another study, the antioxidants vitamin C and N-acetyl cysteine (often sold under the name “NAC”) significantly reduced the effectiveness of anti-cancer drugs Vinblastine and Cisplatin.9

As more recent studies continue to suggest antioxidants could actually help cancer cells grow, research by Zachary Schafer shows that cancer cells’ survival can be aided by antioxidants that protect these cells from free radicals.10 Free radicals harm cells, and getting rid of free radicals therefore can help cancer cells. “If you are a person who is healthy, meaning no tumors of any kind, antioxidants are probably going to protect against cancer,” Schafer says. But he points out that if a person has cancer cells, antioxidants can help those cancer cells survive.

The bottom line

Dietary supplements are intended to be used when your body is not receiving certain nutrients in the right amounts, but like drugs, they can have unintended side effects so they should only be taken as recommended.

If a person definitely doesn’t have cancer, antioxidants can help them.  However, if they have cancer, even if they have early cancer that hasn’t been diagnosed yet (which is certainly a risk for heavy smokers or former smokers, for example), antioxidants could be harmful.

It may be tempting to go out and buy nutritional products that claim to be all-natural and will make you feel great and stay healthy. Remember, however, that a product labeled as being “natural” or “organic” is not necessarily safe. The Food and Drug Administration (FDA) does not test the safety and effectiveness of nutritional supplements before they are placed on the shelf the way they do for prescription and over-the-counter medications.  Consequently, you may be purchasing a product that is neither safe nor effective!

So what are some proven strategies that can help reduce your risk of cancer?

  • Maintain a healthy weight by limiting the high-calorie foods you eat and getting regular physical activity
  • Eat plenty of fruits and vegetables every day (fruits and vegetables should cover half of your plate. For more tips, see My Plate: A New Alternative to the Food Pyramid)
  • Limit the amount of red meat and processed meat (hot dogs, sausages, bologna, etc.) that you eat
  • Eat foods made of whole grains

Weight and cancer: What you need to know

Diet, Habits, & Other Behaviors
Brandel France de Bravo, MPH, Noy Birger, Shahmir Ali ABD, and Ealena Callender, MD, MPH,  Cancer Prevention and Treatment Fund

There are many reasons why being overweight is bad for our health, but most people
don’t realize that cancer is one of them.  Of course, excess body weight can contribute
to serious medical conditions such as heart disease and type II diabetes. Still, more
recent research shows that excess body fat also increases the risk of developing certain
types of cancer.

Researchers estimate that more than 481,000 of newly-diagnosed cancer cases
worldwide in 2012 were due to overweight or obesity. [1] An estimated 111,000 cancer
cases in North America are caused by being overweight or obese. This represents 23%
of total global cancer cases – the highest of any region. In addition, three cancers
accounted for 73% of all obesity-related cancers among women globally: endometrial
cancer, postmenopausal breast cancer, and colon cancer. For men, kidney and colon
cancers accounted for 66% of all obesity-related cancers. Other cancers associated
with overweight and obesity include prostate cancer, several gastrointestinal cancers,
and non-Hodgkin’s lymphoma.

In 2018, American Cancer Society researchers concluded that each year from 2011 to
2015, approximately 37,700 cancer cases in men in the U.S. and 74,700 cancer cases
in women aged 30 years or older were attributable to excess body weight. [2] Among men,
the excess cancers ranged from 3.9% in Montana to 6.0% in Texas. In women, the
excess risk of cancer was almost twice as high as for men, ranging from 7.1% in Hawaii
to 11.4% in Washington, DC. The highest number of weight-related cancers were
primarily found in southern and midwestern states, as well as Alaska and Washington,
D.C. Overall, cancers attributable to excess body weight account for at least 1 in 17 of
all cancers in each state.

The good news is that a large 2014 study showed that with a healthy diet and regular
exercise, postmenopausal women may significantly reduce their cancer risk. [3]  In the
study, researchers defined a healthy diet as one that limits red meat and processed
meat, emphasizes whole grains over refined grains, and includes two and a half cups of
vegetables and fruits daily. In addition, regular exercise involves at least 150 minutes of
moderate-intensity physical activity or 75 minutes of vigorous-intensity physical activity
every week. Those with the healthiest diets and most active lifestyles saw their chance
of getting breast cancer drop by 22%, their likelihood of colon cancer drop by 52%, and
their overall chance of dying during the 12-year study drop by 27%. While all the women
who ate better and exercised more lowered their chances of developing cancer, non-
white women seemed to benefit the most.

A 2020 study of more than 8,000 Black and White men and women also found that
exercise helps lower the likelihood of dying from cancer. The study found that inactive
people (whether couch potatoes or sitting at a desk all day) were more likely to die from
cancer. At the same time, those who engaged in light to moderate physical activity were
less likely to die from cancer. [4]

In 2022, a study of adults aged 59 to 82 found that those who were as physically active
as was recommended by the Physical Activity Guidelines for Americans were less likely
to die of cancer than those who were less active. [5] All men and women in the study
who were at least moderately active were less likely to die from cancer or
cardiovascular disease than those who were not active at all. In addition, when
researchers evaluated the type and intensity of activity, the activity that seemed most
likely to reduce the chance of dying from cancer was running, followed by other aerobic
exercise, swimming, and cycling.

How does obesity increase the risk of developing cancer?

Excess body weight results in extra body fat – which has unique features that can make
it more likely for an obese person to get cancer. [6] Body fat, also known as adipose
tissue, contains an abundance of cells that cause chronic inflammation and make it
easier for tumors to grow.

Chronic inflammation in individuals with excess body fat may also contribute to insulin
resistance. [7]  Insulin is a hormone that helps our cells use glucose – a type of sugar
found in the foods we eat – to make energy. Insulin resistance means our bodies can’t
respond properly to insulin, and the glucose we need for energy stays in our blood,
where it can’t be used. Too much glucose in our blood – also referred to as high blood
sugar levels or hyperglycemia – increases the likelihood of getting and dying from
cancer. [8] Elevated blood sugar levels lead to an increase in insulin and similar hormones
that cause tumors to grow. The higher the insulin level of a breast cancer patient, the
greater the chance of death. [9] For example, one study of non-diabetic women with early-
stage breast cancer found that women with the highest fasting insulin levels had three
times the risk of recurrence and death compared with women with the lowest insulin
levels. High insulin levels may also interfere with the way certain cancer drugs work,
making treatments less effective. [10]

Researchers think the danger of excess weight is partly due to hormones secreted by
fat tissues, such as estrogen. In women, estrogen comes from a different source before
and after menopause. Before menopause, a woman’s ovaries secrete estrogen. After
menopause, estrogen comes from other tissues in the body. For obese postmenopausal
women, most estrogen comes from body fat, which can encourage the growth of cancer
cells. [11,12] Increased estrogen and increased body fat increase the likelihood of
developing postmenopausal breast cancer and endometrial cancer (also called cancer
of the uterus) in women. [11,12]

The location of body fat also may be important. Fat tissue deep inside your body
wrapped around your organs may increase the risk of developing cancer. For example,
one study followed 3,086 men and women for up to seven years and used medical
imaging scans and physical exams to assess the location of excess fat deposits. [13] After
statistically controlling for the effects of age, exercise habits, BMI, and eating habits,
researchers concluded that those with more fat deep inside the body, compared to
those with fat mostly just beneath the skin, were more likely to develop heart disease
and cancer.

How new is this news?

Researchers have documented the link between obesity and cancer
for many years. In 2003, based on a study of more than 900,000 adults, researchers
estimated that 90,000 cancer deaths could be avoided if adults maintained a normal
body weight. [14] Of all deaths from cancer in Americans over age 50, as many as 14% in
men and 20% in women may be attributable to overweight and obesity. [15]

Every additional study helps to explain how it is that fat fuels tumor growth. Renehan et
al.’s 2012 study, which seemed to be groundbreaking at the time, is based in part on an
earlier meta-analysis (a type of statistical analysis that combines many studies) in which
many of the same authors analyzed more than 200 comparable data gathered from
different countries around the world. [16] The meta-analysis found that excess weight in
men was most strongly associated with cancer of the esophagus, thyroid, colon, and
kidneys. According to the meta-analysis, being overweight did not appear to increase a
man’s risk of prostate cancer. On the other hand, one U.S. study found that an
overweight man with prostate cancer is more likely to die of it than a man with prostate
cancer who is not overweight. [17]

According to the meta-analysis, excess weight in women increases the chances of
developing endometrial cancer, cancer of the gallbladder, esophagus, and kidneys. A
few other cancers were also associated with being overweight for both men and
women, including leukemia, multiple myeloma, and non-Hodgkin’s lymphoma, but the
link was weaker. In men, rectal cancer and malignant melanoma also seemed related to
weight. In women, those with a higher BMI were slightly more likely to be diagnosed
with post-menopausal breast cancer, cancers of the pancreas and thyroid, and colon
cancer.

Additional studies have come to similar conclusions. For example, the American
Institute for Cancer Research (AICR) estimated that excess body fat is responsible for
49% of endometrial cancers; 35% of esophageal cancers; 28% of pancreatic cancers;
24% of kidney cancers; 21% of gallbladder cancers; 17% of breast cancers; and 9% of
colon cancers. [18]  In addition, AICR estimates that over 100,000 new cases of cancer
each year are due to excess body fat, which is similar to estimates from the 2018
American Cancer Society study.

Neuhouser’s study, conducted at 40 U.S. clinical centers, of women ages 50 to 79
followed for about 13 years, showed that women who gained more than 5% of their
baseline weight during the study’s follow-up period had a modest increase in their
chance of getting breast cancer. [19] The risk was most significant for women with a body
mass index (BMI) over 35 — they were 60% more likely to develop breast cancer than
women of normal weight. Keep in mind that a BMI of 30 or higher is considered obese.

A 2016 study found that the link between obesity and cancer is more robust in some
countries than others. [20] Middle Eastern countries have the highest proportion of
overweight and obesity in the world and a high proportion of obesity-related cancer. [20] In contrast, countries in sub-Saharan Africa and Asia have only seen a limited increase in
BMI over the last 30 years. Likewise, North America and Europe have a large proportion
of obesity-related cancers, while countries in sub-Saharan Africa and Asia have a
smaller proportion of obesity-related cancer.

Several studies show that high dietary fat intake increases the risk of post-menopausal
breast cancer, [21]  prostate cancer, [22]  and pancreatic cancer. [23] Researchers have also
found that high-fat diets may increase the likelihood of death from cancer, while low-fat
diets reduce the chances of cancer recurrence. [24] It is unclear whether weight or diet is a
stronger predictor of increased cancer risk, although red meat and processed meat
have been found to increase the risk of some cancers. For more information, see our
articles entitled “Red Meat: The News is Not Good” and “Are Processed Meats More
Dangerous Than Other Red Meats?”

Does losing weight reduce your risk of cancer?

Can losing weight help prevent you from getting cancer? The evidence is clear for some
cancers but not for others. For example, postmenopausal women who lose weight may
reduce their chance of getting breast cancer. [25] Also, weight loss may reduce the
likelihood of gastroesophageal reflux – which may be linked to esophageal cancer. In
addition, some studies have found an association between weight loss and decreased
chance of getting prostate cancer.

Men and women who experience significant weight loss after bariatric surgery may
decrease their likelihood of getting cancer. Bariatric surgery, also called weight-loss
surgery, is generally associated with a decrease in body weight of 20% to 35%. [26] A
2022 study of 30,318 men and women compared the incidence of cancer and cancer-
related death between obese patients who had bariatric surgery and those who did not.
The incidence of most types of cancer and cancer-related death was lower in the
surgical weight loss group. This difference was most significant for endometrial cancer –
the cancer most strongly associated with obesity.

Other studies of obese patients who intentionally lost weight found a decrease in certain
factors in the blood that encourage tumor growth. Called tumor growth factors, these
markers represent chronic inflammation and create a setting that makes it easier for cancer cells to grow. [27,28]  Estrogen – a hormone associated with postmenopausal breast cancer and endometrial cancer – also decreased in women who intentionally lost weight. [27] The study found that women who experienced just a 10% weight loss saw their blood estrogen levels decrease by at least 33%. Overall, researchers have not reached a conclusion about the association between weight loss and postmenopausal breast cancer. Although one study showed a decreased likelihood when the weight loss occurs after age 30 but before menopause, [28] other studies have found no impact at all. [29]

What we know and don’t know

Decreasing the likelihood of getting cancer is one of the many benefits of achieving and
maintaining a healthy body weight. However, we still do not fully understand how a
person’s weight, diet, level of physical activity, and genes all work together to determine
one’s cancer risk.

Bottom Line

After giving up tobacco, watching your weight and staying active are your best forms of
health insurance. For guidelines and tips on living a healthy lifestyle, read Eating Habits
That Improve Health and Help with Weight Loss and BMI. [30]

All articles are reviewed and approved by Dr. Diana Zuckerman and other senior staff.

The National Center for Health Research is a nonprofit, nonpartisan research, education and advocacy organization that analyzes and explains the latest medical research and speaks out on policies and programs. We do not accept funding from pharmaceutical companies or medical device manufacturers. Find out how you can support us here.

References:

  1.  Arnold M, Pandeya N, Byrnes G, et al. Global burden of cancer attributable to high
    body-mass index in 2012: a population-based study. The Lancet Oncology.
    2015;16(1):36-46. doi:10.1016/S1470-2045(14)71123-4
  2.  Islami F, Goding Sauer A, Gapstur SM, Jemal A. Proportion of Cancer Cases
    Attributable to Excess Body Weight by US State, 2011-2015. JAMA Oncology.
    2019;5(3):384-392. doi:10.1001/jamaoncol.2018.5639
  3. Thomson CA, McCullough ML, Wertheim BC, et al. Nutrition and Physical Activity
    Cancer Prevention Guidelines, Cancer Risk, and Mortality in the Women’s Health
    Initiative. Cancer Prevention Research. 2014;7(1):42-53. doi:10.1158/1940-
    6207.CAPR-13-0258
  4. Gilchrist SC, Howard VJ, Akinyemiju T, et al. Association of Sedentary Behavior
    With Cancer Mortality in Middle-aged and Older US Adults. JAMA Oncol.
    2020;6(8):1210. doi:10.1001/jamaoncol.2020.2045
  5.  Watts EL, Matthews CE, Freeman JR, et al. Association of Leisure Time Physical
    Activity Types and Risks of All-Cause, Cardiovascular, and Cancer Mortality Among
    Older Adults. JAMA Network Open. 2022;5(8):e2228510.
    doi:10.1001/jamanetworkopen.2022.28510
  6. Khanna D, Khanna S, Khanna P, Kahar P, Patel BM. Obesity: A Chronic Low-Grade
    Inflammation and Its Markers. Cureus. Published online February 28, 2022.
    doi:10.7759/cureus.22711
  7. Gutierrez DA, Puglisi MJ, Hasty AH. Impact of increased adipose tissue mass on
    inflammation, insulin resistance, and dyslipidemia. Curr Diab Rep. 2009;9(1):26-32.
    doi:10.1007/s11892-009-0006-9
  8. Stocks T, Rapp K, Bjørge T, et al. Blood Glucose and Risk of Incident and Fatal
    Cancer in the Metabolic Syndrome and Cancer Project (Me-Can): Analysis of Six
    Prospective Cohorts. Wareham NJ, ed. PLoS Med. 2009;6(12):e1000201.
    doi:10.1371/journal.pmed.1000201
  9.  Hede K. Doctors Seek To Prevent Breast Cancer Recurrence by Lowering Insulin
    Levels. JNCI Journal of the National Cancer Institute. 2008;100(8):530-532.
    doi:10.1093/jnci/djn119
  10. Boyd DB. Insulin and Cancer. Integr Cancer Ther. 2003;2(4):315-329.
    doi:10.1177/1534735403259152
  11. Cleary MP, Grossmann ME. Obesity and Breast Cancer: The Estrogen Connection.
    Endocrinology. 2009;150(6):2537-2542. doi:10.1210/en.2009-0070
  12. Kaaks R, Lukanova A, Kurzer MS. Obesity, Endogenous Hormones, and
    Endometrial Cancer Risk: A Synthetic Review1. Cancer Epidemiology, Biomarkers
    & Prevention. 2002;11(12):1531-1543. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4142485/
  13. Britton KA, Massaro JM, Murabito JM, Kreger BE, Hoffmann U, Fox CS. Body Fat
    Distribution, Incident Cardiovascular Disease, Cancer, and All-Cause Mortality.
    Journal of the American College of Cardiology. 2013;62(10):921-925.
    doi:10.1016/j.jacc.2013.06.027
  14. Calle EE, Rodriguez C, Walker-Thurmond K, Thun MJ. Overweight, Obesity, and
    Mortality from Cancer in a Prospectively Studied Cohort of U.S. Adults. N Engl J
    Med. 2003;348(17):1625-1638. doi:10.1056/NEJMoa021423
  15. NCI. Home | Cancer Trends Progress Report. Published March 2020. Accessed
    January 10, 2023. https://progressreport.cancer.gov/
  16. Renehan AG, Tyson M, Egger M, Heller RF, Zwahlen M. Body-mass index and
    incidence of cancer: a systematic review and meta-analysis of prospective
    observational studies. The Lancet. 2008;371(9612):569-578. doi:10.1016/S0140-
    6736(08)60269-X
  17. Wright ME, Chang SC, Schatzkin A, et al. Prospective study of adiposity and weight
    change in relation to prostate cancer incidence and mortality. Cancer.
    2007;109(4):675-684. doi:10.1002/cncr.22443
  18. Nelson M. Large study finds (again) obesity links to many cancers. American
    Institute for Cancer Research. Published March 1, 2017. Accessed January 10,
    2023. https://www.aicr.org/resources/blog/large-study-finds-again-obesity-links-to-
    many-cancers/
  19.  Neuhouser ML, Aragaki AK, Prentice RL, et al. Overweight, Obesity, and
    Postmenopausal Invasive Breast Cancer Risk: A Secondary Analysis of the
    Women’s Health Initiative Randomized Clinical Trials. JAMA Oncol. 2015;1(5):611.
    doi:10.1001/jamaoncol.2015.1546
  20. Arnold M, Leitzmann M, Freisling H, et al. Obesity and cancer: An update of the
    global impact. Cancer Epidemiology. 2016;41:8-15.
    doi:10.1016/j.canep.2016.01.003
  21. Wynder EL, Cohen LA, Muscat JE, Winters B, Dwyer JT, Blackburn G. Breast
    Cancer: Weighing the Evidence for a Promoting Role of Dietary Fat. JNCI Journal of
    the National Cancer Institute. 1997;89(11):766-775. doi:10.1093/jnci/89.11.766
  22. Giovannucci E, Rimm EB, Colditz GA, et al. A Prospective Study of Dietary Fat and
    Risk of Prostate Cancer. JNCI Journal of the National Cancer Institute.
    1993;85(19):1571-1579. doi:10.1093/jnci/85.19.1571
  23. Thiébaut ACM, Jiao L, Silverman DT, et al. Dietary Fatty Acids and Pancreatic
    Cancer in the NIH-AARP Diet and Health Study. JNCI: Journal of the National
    Cancer Institute. 2009;101(14):1001-1011. doi:10.1093/jnci/djp168
  24. Chlebowski R. Lifestyle Change Including Dietary Fat Reduction and Breast Cancer
    Outcome. The Journal of Nutrition. 2007;137(1):233S-235S.
    doi:10.1093/jn/137.1.233S
  25. Wolin KY, Colditz GA. Can weight loss prevent cancer? Br J Cancer.
    2008;99(7):995-999. doi:10.1038/sj.bjc.6604623
  26. Aminian A, Wilson R, Al-Kurd A, et al. Association of Bariatric Surgery With Cancer
    Risk and Mortality in Adults With Obesity. JAMA. 2022;327(24):2423.
    doi:10.1001/jama.2022.9009
  27. Byers T, Sedjo RL. Does intentional weight loss reduce cancer risk? Diabetes,
    Obesity and Metabolism. 2011;13(12):1063-1072. doi:10.1111/j.1463-
    1326.2011.01464.x
  28. Harvie M, Howell A, Vierkant RA, et al. Association of Gain and Loss of Weight
    before and after Menopause with Risk of Postmenopausal Breast Cancer in theIowa Women’s Health Study. Cancer Epidemiology, Biomarkers & Prevention.
    2005;14(3):656-661. doi:10.1158/1055-9965.EPI-04-0001
  29. Teras LR, Goodman M, Patel AV, Ryan Diver W, Dana Flanders W, Feigelson HS. Weight loss and postmenopausal breast cancer in a prospective cohort of overweight and obese US women. Cancer Causes Control. 2011;22(4):573-579. doi:10.1007/s10552-011-9730-y
  30. Dudley S, Pederson S, Kennedy C, Rosseau N. Eating Habits That Improve Health and Help with Weight Loss and BMI. National Center for Health Research. Published March 29, 2010. Accessed January 10, 2023. https://www.center4research.org/eating-habits-improve-health-help-weight-loss-bmi/

 

Good news for coffee drinkers: the health benefits outweigh the risks for most people

Colon Cancer, Diet, Habits, & Other Behaviors, Other Cancers, Skin Cancer, Skin Cancer
By Morgan Wharton, Jessica Cote, and Shahmir Ali ABD

latte-249102_640Most Americans drink coffee every day.11 The caffeine in coffee helps us stay alert but also may cause jitteriness and interfere with sleeping. A few studies suggest that decaffeinated coffee also has health benefits, perhaps because of antioxidants or acids in the coffee bean.12

What Are The Health Benefits Of Drinking Coffee?

For years medical experts advised people to drink less coffee, mostly because of research suggesting coffee might increase the risk of heart disease. However, numerous studies conducted recently have discovered coffee’s unexpected health benefits. Like all well-designed research, most of these studies considered the impact of age, sex, body mass index (BMI), physical activity, tobacco use, and whether family members had developed cancer. By controlling for those factors, researchers made sure they could separate coffee’s impact on health from the effects of people’s lifestyle, family history, and previous health problems. However, the type of coffee you drink may influence its health benefits; a very large study from the UK published in 2022 found that adults who drank larger quantities of unsweetened or sugar-sweetened coffee were less likely to die from cancer in the subsequent 7 years, and also less likely to die from any cause during that time frame.13  However, drinking more artificially sweetened coffee had no impact on cancer or other deaths.

Colorectal Cancer

Meta-analyses are a kind of statistics that combine data from several comparable studies to make one very large study. These results are usually more accurate than any one study can be. Taken together, three meta-analyses suggest that drinking about four or more cups of coffee per day may reduce the chances of getting colorectal cancer by 11-24%.141516

Endometrial (uterine) Cancer

Using data from 67,470 women who participated in the Nurses’ Health Study, researchers found that women who drank four or more cups of coffee per day were 25% less likely to develop endometrial cancer than women who drank only one cup of coffee per day. Compared to women who did not drink any coffee, those who drank four cups or more per day were 30% less likely to develop endometrial cancer. Decaffeinated coffee was just as effective as caffeinated coffee, but caffeinated tea did not lower the risk of endometrial cancer.17

Liver Cancer And Cirrhosis (Scarring of the Liver/Chronic Liver Disease)

One study found people who drank one or two cups of coffee per day had a slightly lower risk of getting the most common type of liver cancer compared to non-drinkers, but people who drank three or four cups of coffee were about half as likely as non-drinkers to get this kind of liver cancer. Meanwhile, people who drank five or more cups per day had an even lower risk than that (about one-third the risk of non-drinkers).18

Similarly, a study in Japan found a 76% decrease in the risk of that type of liver cancer in people who drank at least five cups of coffee per day compared to those who did not drink coffee. The strongest benefit was seen in individuals with hepatitis C, a disease which increases a person’s risk of developing liver cancer, although the researchers were not sure why.19

A study of 120,000 Americans over an 8-year period found a 22% decrease in the chances of developing cirrhosis for each daily cup of coffee. In Norway, a 17-year study of 51,000 citizens found that those who drank two or more cups of coffee per day were 40% less likely to develop cirrhosis compared to those who did not consume coffee.20

Skin Cancer

Using data from two enormous studies, the Nurses’ Health Study and the Health Professionals Follow-up Study, researchers found that men and women who drank more than three cups of caffeinated coffee per month were 17% less likely to develop basal cell carcinoma compared to people who drank less than one cup per month. Basal cell carcinoma is the most common and least dangerous type of skin cancer. Drinking decaffeinated coffee did not affect basal cell carcinoma.21

A 2014 study in the Journal of the National Cancer Institute found that the more coffee participants drank, the less likely they were to develop malignant melanoma over a 10 year period. Melanoma is the most dangerous form of skin cancer. Almost 450,000 whites, aged 50-71, participated in the study. Researchers found that drinking four or more cups of coffee per day was linked to a 20% lower risk of getting malignant melanoma. Once again, drinkers of decaffeinated coffee lost out. Their risk of getting melanoma was no different from that of non-coffee drinkers. Coffee drinking, however, did not affect the least dangerous form of melanoma, called melanoma in situ.

Remember that no matter how much coffee with caffeine you drink, the best way to prevent skin cancer is still to limit your time exposed to the sun and ultraviolet light! 22

Type 2 Diabetes

People in Finland consume more coffee than almost any other nation, and a study of 14,000 people over 12 years  found that men who drank 10 or more cups of coffee daily had a 55% lower risk of developing type 2 diabetes than men who drank 2 cups of coffee a day or fewer.  Even more dramatic, women who drank 10 or more cups per day had a 79% lower risk of developing type 2 diabetes than those who drank fewer than 2 cups daily.23

A different Finnish study of 5,000 sets of identical twins found that individuals who drank more than seven cups of coffee per day had a 35% lower risk of type 2 diabetes than their twins who drank two cups or fewer per day.24 Because identical twins are so biologically similar, the difference in disease risk is very likely caused by coffee consumption levels. Studies of fewer people in other countries have found less dramatic but similarly positive results.

Parkinson’s Disease

A study of more than 8,000 Japanese-American men found that men who did not drink coffee at all were three to five times more likely to develop Parkinson’s disease within 30 years than men who drank four and a half cups or more of coffee per day.25

Suicide

Because suicide may be related to alcohol intake, medications, and stress levels, suicide studies took those factors into account.  A 10-year study of 128,000 people in California found that the risk of suicide decreased by 13% for every additional cup of coffee consumed per day. Even one cup of coffee per day seemed to reduce the risk of suicide. A different 10-year study of 86,000 women found a 50% lower risk of suicide for those who drank two or more cups of coffee per day compared to women who did not drink coffee.26

Brain Power and Aging

A study of 676 healthy men born between 1900 and 1920 suggested that coffee helped with information processing and slowed the cognitive decline typical of aging. Cognitive functioning was measured by the Mini-Mental State Examination, a 30 point scale. Men who regularly consumed coffee experienced an average decline of 1.2 points over 10 years, while men who did not drink coffee saw a decline of 2.6 points over 10 years. Men who drank three cups of coffee per day declined only 0.6 points over 10 years.27

Even old mice are sharper with caffeine: a study using a mouse model of Alzheimer’s disease showed that coffee actually reversed the cognitive decline and slow-down in processing that occurred with age. Mice given caffeine in their water showed signs of recovering their memory during testing.28

What about the risks?

Childbearing

Two separate studies found that 300 mg of caffeine (two to three cups of coffee) decreased a woman’s chances of getting pregnant by more than a third. This same amount of coffee also increased the chances of women having low birth-weight babies by 50%. These studies took into account potentially influential  factors such as contraception used in the past and infertility history.29

Hip Fracture

According to data from the Nurses’ Health Study, women aged 65 and over who drank more than four cups of coffee per day had almost 3 times as many hip fractures over the next six years as women who did not drink coffee. Researchers took important factors into consideration such as how much calcium the women consumed each day.30

Parkinson’s Disease among post-menopausal women taking estrogen-only hormone therapy

Other researchers used data from the Nurses’ Health Study to evaluate the risk of Parkinson’s disease among women who drank coffee while using estrogen medication after menopause. For women who were NOT using estrogen therapy, those who drank four or more cups of coffee per day were about half as likely to develop Parkinson’s disease as women who did not drink coffee. For women who did use post-menopausal estrogen, however, those who drank four or more cups of coffee were about twice as likely as those who didn’t drink coffee to develop Parkinson’s.31

Heart Disease

Two different meta-analyses found that people who drank five or more cups of coffee per day were 40-60% more likely to develop heart disease compared to those who did not drink coffee at all. Other studies have also shown that high coffee use (five to ten cups per day) increases the risk of heart disease, while moderate consumption (three to four cups daily) was not associated with a higher risk. Only coffee drinkers who consumed more than nine cups a day had a greater risk of dying from heart disease.32 It is important to consider that people drinking close to 10 cups of coffee a day are likely to have other health problems, such as stress or sleep deprivation, and this could contribute to higher risk of heart disease and death regardless of coffee use.

Bottom line

For most people, drinking coffee seems to improve health more than harm it. Many of coffee’s health benefits increase with the number of cups per day, but even one cup a day lowers the risk of several diseases. However, women who want to get pregnant or already are pregnant and women over 65 should probably limit their coffee intake because, in their case, the risks may outweigh the health benefits.

Even though many studies show coffee has benefits, it’s still not clear why. How can one popular beverage help metabolism (for example, lowering the risk of type 2 diabetes) and also protect against a range of cancers? Until further research can solve that puzzle, most adults should continue to enjoy their cup (or two, or three) of Joe. Finally, remember that nearly all studies on coffee and health have been done on adults. Coffee may affect children and teens differently.

Are Pesticides, Roundup, and Cancer in Children Connected?

Diet, Habits, & Other Behaviors, Environmental Exposures,
By Prianka Waghray and Avni Patel
2022

In murder mysteries, rat poison and pesticides intentionally added to food are sometimes used to kill.  Scientists have also warned they can cause birth defects.  However, more recent research shows that relatively low levels of pesticides and indoor bug sprays can cause cancer and other serious medical problems in children, and possibly adults.

A study published in 2020 found that children exposed to pesticides are more likely to develop cancer later in life. The study highlights an urgent need to prevent and child’s exposure to pesticides 1. Although it was already known that many chemicals used in pesticides, such as certain organophosphates, can cause cancer, the study aimed to find out how much exposure is likely to cause cancer in children.

The evidence about the risks of various chemicals has been growing. There is some evidence that high level of exposures to pesticides, especially among farm workers, may increase the chances of developing lung cancer, but more research is needed on which pesticides are most likely to cause harm 2. In 2019, a University of  Washington study showed that the use of a widely used weed killer called Roundup increases the chances of contracting non-Hodgkin lymphoma by 21% 3.  Children are especially vulnerable to even small amounts of insecticides and pesticides that are meant to kill rodents or insects, even in tick and flea sprays used on pets, because children are smaller than adults and their bodies and brains are still developing.  Roundup, which has been banned in 41 countries as of 2021 due to health concerns, as well as other weed killers are currently being investigated by scientists to learn more about the risks for adults and children. 4.

Even before the latest study, the American Academy of Pediatrics (AAP), which is the nonprofit organization for pediatricians, warned that children can be harmed by pesticides in their daily life.5. The AAP concludes that exposure to pesticides early in life can result in childhood cancers, behavioral problems, and lower scores on tests to measure thinking, reasoning, and remembering. They recommend that parents reduce their children’s exposure to pesticides as much as possible, by controlling bugs and other pests using non-chemical methods whenever possible, and by reducing the amount of pesticides in what children eat and drink.

Several studies have found, for instance, that children exposed to organophosphates, which are common in household insecticides, in their early years tend to have lower IQ and more likely to show the behaviors typical of autism and attention deficit and hyperactivity disorders.6

Several cancer-causing organophosphates have been banned from household pesticides. Unfortunately, they have been replaced with other organophosphates that have not yet been studied. Whether or not these chemicals cause cancer, they can be dangerous and children should not be exposed to them.8

Young children are more likely to be exposed to more pesticides and insecticides than adults because they are closer to the ground and often put whatever they find there, along with their own fingers, in their mouths. When bug spray or other pesticides are used in the home, chemical residues can linger in the air, on the floor or carpet where children crawl and play, and on toys.33 Children breathe in more pesticide than adults, too, because they are down low where the chemicals accumulate. Lawn and garden weed killers can be tracked in the house by pets or people, and left in carpets and rugs.

How can we reduce children’s exposure to pesticides?

The good news is that parents can reduce their children’s exposure to these chemicals. The easiest way is to stop using them in your home and garden. It is also safer to use roach motels, ant baits, and mouse traps instead of chemical sprays. You can weed the yard by hand instead of using weed killers (at least while your children are young).

What about the fruits and vegetables that you buy?  Be sure to wash, scrub, and peel fruits and vegetables if you don’t buy organic produce. Although washing and peeling fruits and vegetables doesn’t get rid of the pesticides that have been absorbed into the growing vegetable or fruit, it is still better than nothing. However, if you can afford to buy them, organic fruits and vegetables have the least amount of pesticide on and inside the fruit or vegetable.34

One way to reduce the use of bug sprays and other chemicals in the home is to not leave out food overnight that can attract bugs or rodents. Discourage rats by covering garbage cans.

If you must use pesticides, use the ones that are less toxic. If you aren’t sure how a product kills pests, look at the label. According to the EPA, pesticides with “warning” on the label are more dangerous to humans than the ones that say “caution.” Products with labels that say “danger” are the most harmful.35 36 Besides using the lowest risk products, be careful where you store pesticides, so that children can’t reach them and the chemicals won’t contaminate foods or medicines.

Is buying organic really better for you?

Researchers at Stanford University have concluded that organic fruits and vegetables are not more nutritious than other produce. However, they also found that children who eat organic produce have significantly lower levels of pesticides in their bodies than children who eat regular produce.37,38,39

Unfortunately, organic fruits and vegetables are not always available, and they are often more expensive. One way to eat organic less expensively is to limit your organic purchases to the fruits and vegetables on the Environmental Working Group’s (EWG) Dirty Dozen list.40 These are the 12 fruits and vegetables that tend to have the highest amount of pesticide residues. The list is constantly being updated based on recent test results so check it regularly (http://www.ewg.org/foodnews/). There is also a Clean 15 list, which lists 15 foods that have the least amount of pesticides and, therefore, are safe even when they are not organic. By following these lists, you can feed your children more safely without breaking the bank.

As of Feburary 2022, the Dirty Dozen consists of the following foods:

  1. Strawberries
  2. Dirty dozen; peachesSpinach
  3. Kale, collard, and mustard greens
  4. Nectarines
  5. Apples
  6. Grapes
  7. Cherries
  8. Peaches
  9. Pears
  10. Bell and hot peppers
  11. Celery
  12. Tomatoes

The Clean 15 list consists of the following foods, where it is not necessary to buy organic:

  1. Avocados
  2. Sweet Corn
  3. Pineapples
  4. Onionsclean 15; red onions
  5. Papaya
  6. Sweet Peas (frozen)
  7. Eggplant
  8. Asparagus
  9. Broccoli
  10. Cabbage
  11. Kiwi
  12. Cauliflower
  13. Mushrooms
  14. Honeydew Melon
  15. Cantaloupe

THE BOTTOM LINE

Even small amounts of pesticides are very harmful for children. They may cause behavior problems, harm children’s thinking and memory, and increase their risk of childhood cancers.  These chemicals can also harm adults, especially after years of exposure.  To help prevent these problems, limit your use of bug sprays, weed killers, and other pesticides and herbicides and buy organic fruits and vegetables that would otherwise have a lot of pesticide residue.

All articles on our website have been approved by Dr. Diana Zuckerman and other senior staff. 

 

Lung cancer is a women’s health issue

Diet, Habits, & Other Behaviors, Lung Cancer, Lung Cancer

By Susan Dudley, PhD, Renee Y. Carter, MD, Tiffanie Hammond, and Amrita Ford, MA

Risk Factors for Lung Cancer
Non-Smokers and the Possible Role of Estrogen
Surviving Lung Cancer
Racial and Ethnic Differences in Lung Cancer
Symptoms of Lung Cancer
Lung Cancer Detection and Treatment
Advances in Treatment but They are High-Cost and Only for Some Patients
Funding for Lung Cancer Research

Lung cancer is the #1 cause of cancer death among women in the United States. Lung cancer used to be thought of as a man’s disease, but women now account for almost half of new cases and deaths from lung cancer. In 2014, 48% of the almost 216,000 people diagnosed with lung cancer were women, and 45% of the 155,526 who died from lung cancer were women.41

Lung cancer deaths in women began quickly rising in 1960, and by 1987, the number of female deaths from lung cancer exceeded the number of deaths from breast cancer. Today the number of deaths in women from lung cancer surpasses those from all gynecological cancers combined.42 While the rate of lung cancer deaths among men has been steadily decreasing since the 1990s, the lung cancer death rate among women did not start to go down until a decade later (2003-2007).43 The decline of lung cancer deaths among women, however, may not be as rapid as it has been in men: women born around 1960 with a high rate of smoking are just now entering the age when lung cancer diagnosis is most common.

Risk Factors for Lung Cancer

Everyone knows that smoking is the leading cause of lung cancer. It is responsible for 90% of lung cancer deaths in men and 80% in women. Beginning in the 1940’s during World War II, smoking became more acceptable for American women.44 As more women began to smoke, the number of deaths from lung cancer increased very dramatically among women — by more than 600% between 1950 and 1997. When a woman stops smoking, her risk of developing lung cancer decreases, but not as much as many women may think. Twenty years after stopping, the risk of developing lung cancer drops only by half. In addition, exposure to second-hand smoke at home, work, or other environments—including childhood exposures—can cause lung cancer in women who have never smoked themselves.45

Additionally, exposure to radon, arsenic, asbestos, radiation, air pollution, some organic chemicals, such as benzene, and tuberculosis, also increase the risk of developing lung cancer.

Non-Smokers and the Possible Role of Estrogen

Although smoking increases the risk of lung cancer dramatically, 1 in 5 women diagnosed with lung cancer have never smoked, whereas among men who develop lung cancer, only 1 in 12 have never smoked.446 Of all the types of lung cancer, women are more likely to develop adenocarcinoma, a type of non-small cell lung cancer (NSCLC), which is also the type of lung cancer more commonly found in non-smokers.

It is unclear why non-smoking women are at greater risk for developing lung cancer than non-smoking men. Studies indicate that biological and genetic differences between men and women play a role in susceptibility to lung cancer and the risk of dying from it. Some research shows that estrogen, a hormone found in both men and women but much higher in women, may help certain lung cancer cells to grow and spread throughout the lungs. For example, a 2009 study based on the Women’s Health Initiative showed that post-menopausal women who took estrogen and progesterone combined hormone therapy had an increased risk of dying from lung cancer, regardless of whether they had never smoked, stopped smoking, or were currently smoking (although current and former smokers were at the highest risk for death).47 A 2010 study indicated that post-menopausal women who took hormone therapy for more than 10 years were at an increased risk of developing lungcancer.48  In 2011, a study showed that women who take estrogen-blocking medication like tamoxifen to prevent a recurrence of breast cancer also reduce their risk of dying from lung cancer.49 For both the 2010 and 2011 studies, the link between hormones and lung cancer were maintained regardless of the person’s smoking status. For more information about hormone therapy and lung cancer, read Lung Cancer and Hormone Therapy: Bad News for Former and Current Smokers.

Surviving Lung Cancer

Women are nearly as likely as men to be diagnosed with lung cancer, but on a more positive note, they tend to survive longer than men with the disease. Women generally live longer than men at every stage of lung cancer, regardless of when they were diagnosed, the type of lung cancer they had, or how they were treated.5051 Studies have shown that women with non-small cell lung cancer (NSCLC) have a greater 5-year survival following partial removal of the lung (resection) than men.525354 Women with NSCLC who are treated with chemotherapy prior to removal of the tumor also have better survival rates than men.55 Furthermore, women with advanced lung cancer of any type who undergo chemotherapy survive longer than their male counterparts.56

Why do women with lung cancer live longer than men? No one is really certain. One reason may be that women tend to notice symptoms and go to the doctor earlier than men, allowing the disease to be caught at an earlier stage when the cancer is local (still in the lung) and can be completely removed.57 However, even when researchers control for this and other differences between men and women, women still live longer following surgery.13 For both women and men with lung cancer, complete removal of an entire lobe of the lung (lobectomy) results in higher survival rates than only partial removal of the lung. Younger patients and patients with smaller tumors are more likely to survive lung cancer than those who are older or have larger tumors, regardless of sex.14

Racial and Ethnic Differences in Lung Cancer

The incidence of lung cancer among African American women is about the same as white women yet smoking rates among African American women are lower.58 In 2007, about 16% of African American women smoked, while the rate for white women was about 20%.59 Similarly, African-American men smoke less than white men yet have higher rates of lung cancer. Is there a genetic difference that places African Americans at higher risk? Or are African-Americans exposed to other lung cancer causing bacteria and chemicals that increase their risk?

No one knows the answer yet but there are several explanations for why African Americans—men and women—are more likely to die from lung cancer than white men and women. Even African American women who have never smoked have higher death rates from lung cancer than white women who have never smoked.60 Most experts believe African Americans with lung cancer don’t live as long because they don’t have the same access to health care. For instance, they are less likely to have insurance coverage which could impact diagnosis and treatment options.61 They are less likely to receive timely care and may not receive the most effective treatment for their type of lung cancer.62 One study found that African American patients underwent partial surgical removal of the lung less frequently than white patients. 63 Other factors that may contribute to the lower survival rates of African American lung cancer patients include differences in lung function,20 provider biases,64 inadequate physician-patient communication,65 distrust of physicians and the health care system,66 and a greater likelihood of refusing surgery.67 For more on African Americans and lung cancer, read here.

After African American and white women, native Hawaiian women have the highest incidence of lung cancer, while Hispanic and Japanese women have the lowest rates.20 Unlike other racial and ethnic groups where the incidence of lung cancer in women has increased over time, rates have actually declined among Hispanic women (who are more likely to be non-smokers than African Americans, whites or native Hawaiians): they decreased by 1.5% every year from 1994 to 2003.68 Despite the decline of lung cancer in both men and women, lung cancer remains the leading cause of cancer death among Hispanic men and the second leading cause of cancer death among Hispanic women.

Symptoms of Lung Cancer

The most commonly recognized symptoms of lung cancer include:

  • persistent cough, coughing that wakes you up at night, and/or coughing up blood
  • wheezing and/or shortness of breath
  • chest pain
  • hoarseness
  • swelling of the face and neck
  • loss of appetite and/or unexplained weight loss
  • unusual tiredness
  • recurring pneumonia or bronchitis

Lung Cancer Detection and Treatment

While survival rates for many cancers have improved substantially over the last 30 years, little progress has been made in the survival rate for lung cancer. For example, between 1974 and 2007, the 5-year survival rate for breast cancer increased from 75% to 89% and the 5-year survival rate for prostate cancer increased from 67% to 99%. In contrast, the 5-year survival rate for lung cancer increased from 13% to just under 16% during the same time period.

What would be needed in order for the survival rates for lung cancer patients to parallel that of breast, prostate or cervical cancers? The main problem is that by the time most women are diagnosed with lung cancer, it has already spread to other organs, making a cure extremely unlikely. Pap smears and colonoscopies, for instance, make it possible to diagnose and remove pre-cancerous cells on the cervix or polyps in the colon before they can develop into cervical cancer or colon cancer or spread elsewhere in the body. And while better survival rates for women with breast cancer are mostly attributed to improvements in treatment, mammogram screenings have helped some women by detecting their breast cancer at earlier stages than before, when surgery, radiation, or chemotherapy have an even better chance of eliminating the disease. Earlier diagnosis and more effective treatments, therefore, will be necessary to improve the survival rate of lung cancer.

The National Lung Screening Trial, which started in 2002, evaluated the use of chest x-rays and low-dose computed tomography (low-dose CT scans) for early detection of lung cancer in men and women who were heavy smokers. Each randomized group was screened annually for 3 years. Researchers found that using low-dose CT scans reduced lung cancer deaths by 20% in the high-risk population. Compared to standard x-rays, CT scans may be more effective in detecting nodules and tumors. Based on a 2011 report of the trial, low-dose CT screening could potentially increase the 5-year lung cancer survival rate to 70% if it allowed lung cancer to be detected in its earliest stage (stage 1A), when the tumor is still relatively small, still in the lung, and can be removed easily through surgery.69707172

Although no U.S. public health agency has recommended screening for lung cancer, in January 2013 the American Cancer Society (ACS) did so for the first time, saying that annual screening with low dose CT scans “could save many lives.”73 ACS has recommended that people at highest risk for lung cancer, as defined by the National Lung Cancer Trial, have a discussion with their doctor about the benefits and risks of annual screening. They advised doctors to have this conversation only with patients who match the profile of the people who were enrolled in the National Lung Cancer Screening Trial: current and former smokers who are 55 to 74 years old and have a 30-pack-year history of smoking (20 cigarettes a day for 30 years, 40 cigarettes a day for 15 years, and so on. To calculate your pack years, visit http://smokingpackyears.com/). If the patients are former smokers, they should have quit within the last 15 years.  Doctors should discuss screening with patients only if low dose CT scans and high quality treatment are available in their area, and only if the patient seems healthy and able to undergo treatment in the event that cancer is found.  For all other patients, “there is too much uncertainty regarding the balance of benefits and harms …”

Three other organizations have issued their own slightly different guidelines.  The National Comprehensive Cancer Network has two definitions of high risk: the one used by the American Cancer Society and one that includes people as young as 50 and as old as 79 with only a 20-pack-year history—provided they have one other risk factor for lung cancer such as a family history, Chronic Obstructive Pulmonary Disease (COPD), or exposure to radon.  Given the close link between COPD and lung cancer, the Network’s screening criteria could potentially find more cases of lung cancer than the 30-pack criteria. (For more info on COPD, see Chronic Obstructive Pulmonary Disease and Lung Cancer.) The American College of Chest Physicians and the American Society of Clinical Oncology also have guidelines.  Only time will tell which guidelines work best, but any of these guidelines make it more likely that insurance companies will pay for screening. As a result of the National Lung Cancer Screening Trial, the U.S. Department of Veterans Affairs is starting to implement a screening program using CT scans for veterans at high risk.  However, most government health programs, such as Medicare and Medicaid, do not usually reimburse for lung cancer screening and might not do so until a public health agency has issued guidelines.

Unfortunately, CT scans are not a great solution for finding and diagnosing lung cancer in people who don’t have symptoms and aren’t at high risk. Low-dose CT scans have been shown to produce a high percentage of false positive results (people who the scan says have an abnormality when they don’t have cancer), which can lead to unnecessary lung biopsies. Since lung biopsies can be harmful, low-dose CT as a screening method isn’t useful for the general population. This is unfortunate because women who didn’t smoke are at higher risk than men who didn’t smoke, as are men and women exposed to years of second-hand smoke, but no screening has been found to be appropriate for them. For more information about screening, read Lung Cancer: Who Is at Risk and Can They be Screened?

Advances in Treatment but They are High-Cost and Only for Some Patients

Historically, lung cancer treatments have not been very effective. For instance, erlotinib (trade name Tarceva), which is taken as a pill, extends survival in patients with non-small cell lung cancer by only about 2 months on average and costs anywhere from $2,000 to $5,000 a month.747576 Patients usually take Tarceva after having already undergone chemotherapy, and many use it as a maintenance therapy to prevent further cancer progression and to shrink tumors that are already present. Patients stay on Tarceva for as long as it appears to be having an effect (developing a rash is considered a good sign) and scans show that the cancer is stable. Not only is Tarceva expensive but it doesn’t benefit everyone with lung cancer: it works best in patients who have never smoked or who have a specific gene mutation (EGFR mutation).36[77 Tarceva acts by inactivating the signal in the mutated EGFR gene that makes lung cancer grow.

New targeted treatments that interfere with specific molecules involved in tumor growth and progression and which promote cancer cell death are showing promise in the fight against lung cancer. In August of 2011, the Food and Drug Administration fast-tracked approval for crizotinib (trade name Xalkori) for use in a small subset of lung cancer patients with late-stage, non-small cell lung cancer (NSCLC) who express a rearrangement of the anaplastic lymphoma kinase (ALK) gene. Rearrangement of this gene leads to cancer growth and occurs in 1-7% of NSCLC patients. Xalkori was approved with an accompanying diagnostic test to determine if a patient has the abnormal ALKgene rearrangement.78 Based on an October 2011 study published in Lancet Oncology, the overall survival rate for Xalkori after 1 and 2 years was 74% and 54%, respectively. The recommended dose for Xalkori is 250mg twice daily and the drug costs about $9,600 per month or about $115,000 a year.79 Targeted treatments tend to be very expensive because they are usually taken by a very small number of patients who have limited treatment choices.

Funding for Lung Cancer Research

Far too many women and men are dying of lung cancer every year. Could an increase in research funding result in better screening, earlier diagnosis, more effective treatments, longer survival, and overall lower mortality for patients diagnosed with lung cancer? We believe the answer is “yes.”

The National Cancer Institute is the major source of cancer research funding in the U.S. Comparisons of NCI funding for various types of cancer in 2010 are shown below and clearly show that lung cancer research is under-funded in proportion to how deadly it is for so many people.180 Between 2003 and 2007, NCI funding for lung cancer actually decreased while funding for breast cancer increased.81 The same inequities are seen in funding for prevention. In the Centers for Disease Control and Prevention (CDC) 2008 budget, about $201M was allocated for breast cancer while $104M was allocated for smoking cessation programs (and not lung cancer specifically).82

Total NCI Funding (in millions)

New Cases Diagnosed
(male & female)

Funding per New Case

Overall Deaths

Funding per Patient Death
Lung Cancer

$282.0

221,130

$1,275

156,940

$1,797
Breast Cancer

$631.2

232,620

$2,713

39,970

$15,792
ColonCancer

$270.4

101,340

$2,668

49,380

$5,476
Prostate Cancer

$300.5

240,890

$1,247

33,720

$8,912

 

Many researchers and advocates point to the stigma associated with lung cancer as a reason for why the disease is under-funded.83 Since smoking is associated with the majority of lung cancer cases, many people believe lung cancer patients are responsible for their health problems and therefore not deserving of the same sympathy and research investments that patients of other deadly diseases receive. This attitude may also extend to clinicians who care for lung cancer patients. One study found that physicians were less likely to send their lung cancer patients with advanced stages of the disease to an oncologist than their breast cancer patients.84 Breast cancer patients were also more likely to be referred for further therapy where lung cancer patients were referred for only symptom control. We know now that more complex factors other than cigarette smoking contribute to lung cancer and the lack of funding over the years has hindered researchers from fully understanding why and how this disease progresses in different populations.

So how can we persuade the federal government to fund more lung cancer research? Some think legislation is needed.

In 2008, Congress approved the Peer Reviewed Lung Cancer Research Program which was the first time in history that federal funding was allocated specifically for the study of lung cancer. However, the program is funded by the Department of Defense to study early detection and disease management specifically in military men and women at high risk for lung cancer.

The Lung Cancer Mortality Reduction Act of 2011 is a bipartisan bill currently in Congress which aims to reduce lung cancer mortality by 50% by 2020.85 The bill, first introduced in 2008, calls on the cooperation of the Department of Health and Human Services, Department of Defense, and Veterans Affairs to meet that goal and develop a coordinated plan that addresses the prevention, early detection, and treatment of lung cancer. It would require the National Cancer Institute to review and prioritize research grants related to lung cancer, the Food and Drug Administration to establish quality standards and guidelines for facilities that conduct computed tomography screening for lung cancer, and the Centers for Disease Control and Prevention to establish a Lung Cancer Early Detection Program which would provide low-income, uninsured, and underserved populations at high risk for lung cancer with access to early detection services. For more information and to support this important legislation in the fight against lung cancer, visit http://www.opencongress.org/bill/112-h1394/show.

Smoking cessation products

Diet, Habits, & Other Behaviors, Lung Cancer

It’s hard to quit smoking, but there are products that can help you quit.  No matter how long you have smoked, stopping can decrease your risk of lung cancer and possibly lower your risk of breast cancer.  Here are some important points to remember:

Types of smoking cessation products:

There are two types of smoking cessation products:

  1. Those that contain nicotine to help you reduce your addiction by lowering the levels
  2. Those that do not contain nicotine that are intended to ease withdrawal symptoms

If you use a nicotine replacement product, only use one kind. Do not use gum and a patch on the same day, for example.  Call your health care professional if you experience nausea, dizziness, weakness, vomiting, fast or irregular heartbeat, mouth problems with the lozenge or gum, or redness or swelling of the skin around the patch that does not go away.

Risks

Talk to your health care professional before using these products if you have

  • diabetes, heart disease, asthma, or stomach ulcers
  • had a recent heart attack
  • high blood pressure that is not controlled with medicine
  • a history of irregular heartbeat
  • been prescribed medication to help you quit smoking

Women who are pregnant or breast-feeding should use these products only with approval from their health care professional.

If you take prescription medication for depression or asthma, let your health care professional know if you are quitting smoking; your prescription dose may need to be adjusted.

Products not containing nicotine

Two medicines that do not contain nicotine have FDA’s approval as smoking cessation products. They are Chantix (varenicline tartrate) and Zyban (buproprion). Both are available in tablet form on a prescription-only basis.  Neither of these drugs is recommended for people under 18 years of age.

Both products have serious risks, and can cause changes in behavior, depressed mood, hostility, and suicidal thoughts or actions.  Since quitting smoking is already difficult, does it make sense to take a drug that can make you feel depressed and suicidal. One study found that Chantix is especially likely to cause an increase in reported depression, suicide, and self-injury.  Chantix has other risks as well, and we agree with the researchers who called it “unsuitable” for smoking cessation, unless nothing else has worked.86

Before taking either of these products, read the product’s patient medication guide in its entirety if you use or plan to use either Chantix or Zyban. These guides offer important warnings that you need to know before making a decision.

This article is based on an article on the FDA web site.  For more information, click here.

Quitting smoking: women and men may do it differently

Diet, Habits, & Other Behaviors, Lung Cancer
By Anna E. Mazzucco, Ph.D

Quitting  smoking is hard to do, and new studies suggest that what works for men may not always work for women, and vice versa.  Scientists believe that nicotine is more important for men, while other aspects of smoking seem to be more important for women.  If you are trying to quit, there’s new research that may help you choose the strategy that is most likely to work for you.

Many counselors, quit lines, and other experts recommend talking with your doctor about your interest in quitting or cutting back on the number of cigarettes you smoke. Your doctor will discuss different tools and medications, some of which require a prescription.  Nicotine patches and gum, for instance, can be purchased without a prescription.  These are often used to “step down” nicotine levels (see this article for more information),  but studies have suggested that these medications may work better for men than women, especially when it comes to quitting for good. 87  Other types of medication to help you quit smoking, such as prescription drugs Chantix and Zyban, do not replace nicotine, but instead try to reduce the craving for it.  But these drugs are riskier and have more side effects than nicotine replacements (see this article for more information).

So, what are the other options, especially for women who may not be helped as much by nicotine patches or gum, and who don’t want to use prescription medicines with serious side effects?  Most experts suggest the following:

  1. Plan for success.  Start by picking a good time to quit.  Experts recommend choosing a time of year that is not particularly stressful, since quitting can take a lot of energy.  You might try setting a goal like a “smoke-free” date that is personally meaningful to you—maybe your or a loved one’s birthday, or a holiday.  Some people decide to save the money they would have spent on cigarettes for something special.  If watching your savings accumulate is helpful, consider putting a glass jar somewhere where you can easily see it and get re-inspired daily!  Interestingly, one study showed that women who try to quit during the first half of their monthly cycle (right after menstruation) are more likely to succeed.88
  2. Know yourself.  Quitting can be more successful if you try to identify the situations where you tend to smoke.  Do you have a particular time of day, or group of people that you enjoy smoking with? Anticipate these situations and come up with plans for how to handle them ahead of time.
  3. Find healthier replacements.   Some people find mint gum, lozenges, sunflower seeds or shelled nuts can help reduce their craving for a cigarette.   This may be especially important for women, who often need to replace the hand-to-mouth aspects of smoking as much or more than the nicotine itself.  Research suggests that certain foods might make cigarettes less appealing, such as healthy fruits and vegetables and spicy foods, which might curb the craving for a strong taste.89  Even brushing your teeth can help keep cravings at bay!
  4. Be good to your body.  Regular exercise, such as brisk walking, jogging, yoga or tai chi, can help reduce stress and increase a sense of well-being.  Research suggests that these feel-good replacements may be especially useful for those who smoke to cope with stress. 90  Lungs can quickly begin to heal once you quit smoking.  So breathe deeply and enjoy!
  5. Call in reinforcements.  Next time you feel a craving, try calling a friend, or consider joining a support group.  There are also online quitting tools such as TheExPlan, SmokeFree Women Quit Plan, QuitNet, and Freedom From Smoking Online.  And, you guessed it, there are now many “quitting apps” such as Smoke Out, tweetsmoking, Butt Out, Livestrong MyQuit Coach, and Smoke Break.   Apps can help you count the days since your last cigarette, calculate money saved, show your decreasing risks for diseases, and share your progress with others– and many of them are free. (For a detailed review, see this site). There are also many websites with useful information and links, compiled here by the Center for Disease Control.

Bacteria: the good, the bad, and the ugly

Diet, Habits, & Other Behaviors
Jennifer Yttri, PhD

Bacteria are everywhere, including your entire body. The bacteria in our body weighs as much as our brain–3 lbs! Bacteria can be harmful, but some species of bacteria are needed to keep us healthy. The bacteria on our skin, in our airways, and in our digestive system are the first line of defense against foreign “invaders” (pathogens) that can cause infection and other problems.

Bacteria also act as “tuning forks” for our body’s immune system, making sure it’s pitched just right. The immune system shouldn’t be too sensitive or too sluggish: it needs to respond quickly to an infection but it shouldn’t over-react. (If it does over-react and attacks the body itself, the result is an autoimmune disease, such as rheumatoid arthritis, lupus, or MS). Each person has a personalized collection of bacteria, called the microbiome.91 We acquire our first bacteria while being born, and every day our environment exposes us to more. Some of these bacteria will take up residence inside the body and help develop a robust immune system.

The Good

The species of bacteria that colonize our respiratory and digestive systems help set up checks and balances in the immune system. White blood cells police the body, looking for infections, but they also limit the amount of bacteria that grow there. Likewise, bacteria keep white blood cells from using too much force. Bacteria also help out by doing things cells are ill-equipped to do. For instance, bacteria break down carbohydrates (sugars) and toxins, and they help us absorb the fatty acids which cells need to grow. 92 Bacteria help protect the cells in your intestines from invading pathogens and also promote repair of damaged tissue. Most importantly, by having good bacteria in your body, bad bacteria don’t get a chance to grow and cause disease.

The Bad

Of course, some species of bacteria in your body can result in diseases, such as cancer, diabetes, cardiovascular disease, and obesity. 93  Usually, these diseases happen only when the normal microbiome is disrupted, but that can occur even from antibiotics. Antibiotics kill bacteria, and some of those will be good bacteria that we need to protect our health. When that happens, the bad bacteria that normally are kept in check have room to grow, creating an environment ripe for disease.

Bad bacteria can exist at low levels in your body without causing harm or can grow too much and wreak havoc. Staphylococcus aureus can cause something as simple as a pimple or as serious as pneumonia or toxic shock syndrome. P. gingivalis can cause gum disease, and was recently linked to pancreatic cancer (read our article find out more). Similarly, when not suppressed by good bacteria, Klebsiella pneumonia can cause colitis, and subsequently lead to colorectal cancer. 94

The Ugly

In addition to allowing disease-causing bacteria to flourish, the elimination of good bacteria throws  the immune system out of whack. The result can be simple allergies or very debilitating autoimmune diseases. Without the right balance of bacteria, your body might suffer from constant inflammation.

Inflammation is the body’s alarm system, which calls white blood cells to heal a wound or to get rid of infection. Chronic inflammation, however, can make the body more susceptible to autoimmune diseases and cancer, such as causing inflammatory bowel disease which if uncontrolled can cause colon cancer. 95

The Future

Research suggests that efforts to make a cleaner environment, free from bacteria, are contributing to the rise in obesity, cancer, and heart disease. 96 Experts are trying to figure out how “probiotics” (foods like yogurt with active cultures and dietary supplements that contain live bacteria) can improve our health. Research is underway so  that in the future, specific bacteria may be prescribed as individually tailored treatments for patients.

Our immune system needs the right combination of bacteria so we can stay healthy and rely less on medications. Antibiotics remain a powerful tool to keep us healthy but shouldn’t be used when they aren’t needed. The more we learn, the more we appreciate the power of the bugs inside of us—to heal and not just to do harm.

Related Content:
Pancreatic cancer: could bacteria in our mouth help us detect this deadly cancer sooner?
Fat moms and fat babies? Weight gain during pregnancy
Ten easy tips to get your family eating healthy

Have colon cancer? Skip the hot dogs, deli, and burgers

Colon Cancer, Colon Cancer, Diet, Habits, & Other Behaviors, Uncategorized
Caitlin Kennedy, Ph.D.

New research shows that eating red meat and processed meat increases the risk of colon cancer or of dying from colon cancer. The 2013 Cancer Prevention study by the American Cancer Society has been studying the impact of diet on cancer by following 184,000 patients for 18 years.97

Among the men and women diagnosed with colon cancer, those who ate more than 4 servings per week of red or processed meat before and after they were diagnosed with colon cancer were significantly more likely to die from colon cancer than those who ate fewer than 4 servings per week. Processed meats include deli foods such as hot dogs, sausage, bacon, and bologna, ham and other lunch meats, and bacon. Those who ate more than 4 servings per week had a 79% higher risk of dying from colon cancer compared to those who ate these foods less often. Those who had a family history of colon cancer and ate these foods frequently were especially likely to die from colon cancer.

Remember that “portion” sizes are smaller than what many people typically eat in a meal. For example, 2 hot dogs are considered 2 portions, and one double quarter pound hamburger is considered 3 portions. A large steak could be counted as 3 portions or even more.

Previous research has found connections between eating red meat frequently and an increased likelihood of being diagnosed with colon cancer and other health problems. However, this study is the first to show an increased risk of death from colon cancer.

Bottom line

These very popular foods are more harmful than any of us would like to think. The best way to prevent a variety of health problems, including colon cancer, is to limit red and processed meats in your diet. While the chicken or turkey you make in your oven is fine, the processed chicken and turkey sold at the deli counter or packaged in the supermarket are processed foods. Unfortunately, grilled foods including grilled chicken have also been associated with colon cancer.98 Fish and beans are other healthier sources of protein. If you have a family history of colon cancer, you should be especially careful to eat red and processed meats less frequently. Keep in mind that the American Cancer Society study found an increased chance of dying from colon cancer for men and women who ate these foods either before or after they were diagnosed with colon cancer.

The good news is that it’s never too late to start eating healthy and cutting back on your red and processed meat consumption! Even if someone is already diagnosed with colon cancer, eating less red meat and less processed meat can increase the chances of cancer survival.