Category Archives: Prevention

Prostate Cancer: Diet and Dietary Supplements

Diet, Habits, & Other Behaviors, Prevention, Prostate Cancer
Brandel France de Bravo, MPH, Caitlin Kennedy, PhD, Anna E. Mazzucco, PhD, and Laura Gottschalk, PhD, Cancer Prevention & Treatment Fund

Prostate cancer is the second most common cancer among American men, and the second leading cause of cancer deaths among them as well. The American Cancer Society estimates almost 192,000 new diagnoses of prostate cancer in 2020, and more than 33,000 prostate cancer related deaths.[1] 

Compared to most cancers, prostate cancer usually progresses very slowly, and many men live with it for years and even decades. Once diagnosed, some men decide to undergo treatment to halt the progression of the disease, and others refrain from treatment, preferring instead to closely monitor the cancer’s progression. Those who choose “active surveillance” do this because the medical and surgical treatments for prostate cancer often cause very undesirable side effects, and because most men with prostate cancer will die from something else. This strategy is especially likely for older men in the earliest stage of the disease.

At one time, it was unheard of to suggest that diet might have a role to play in battling prostate cancer. But there is now evidence that certain foods and dietary supplements have an impact on prostate health—both positive and negative. Some foods or supplements appear to promote prostate health and prevent cancer cells from developing, but others should not necessarily be taken by men who already have prostate cancer.

The role of diet drew researchers’ attention when they noticed that prostate cancer rates vary greatly from one country to another, with the highest rates appearing in countries where people tend to eat a lot of fat. Studies also show that men who are obese or have a high fat diet are more likely to have prostate cancer.[2] Diets high in saturated fats, such as the animal fats found in red meat, may pose the greatest risk. The lowest rates of prostate cancer are found in Asian countries where men eat a lot of soy foods, a rich source of naturally occurring phytoestrogens. It was hoped that by increasing men’s intake of phytoestrogens, they might reduce their risk of prostate cancer, slow its progression, or reduce the risk of prostate cancer recurring, but at least three studies have failed to find any protective benefit from phytoestrogens.[4][5][6]

Dietary Supplements

As more and more people take dietary supplements containing antioxidants, studies have been conducted to determine their effect on reducing the risk and growth of cancers, including prostate cancer. Three antioxidants that have received attention with regard to prostate health are vitamin E, selenium, and vitamin D.

Studies comparing men who live in areas of the country with high levels of selenium to men in areas with low levels suggest that this mineral protects against prostate cancer. Selenium was believed to reduce the risk of developing prostate cancer because it keeps cells from proliferating or dying off in a rapid or unusual way. An analysis in 2002 of the Nutritional Prevention of Cancer Trial revealed that the men who took selenium supplements daily were half as likely to be diagnosed with prostate cancer.[7] However, a 2014 report based on the Selenium and Vitamin E Cancer Prevention Trial (SELECT) indicated that selenium supplements increased the risk of prostate cancer by 91% and taking vitamin E supplements increased the risk of prostate cancer by 17%.[8] This result led the researchers to discourage men over 55 from taking amounts of vitamin E higher than the recommended dietary allowance (RDA), which is 15 mg of alpha-tocopherol.  Moreover, a 2009 study found that higher selenium levels in the blood may worsen prostate cancer in many men who already have the disease.[9] As a result of this trial, the researchers have encouraged men over 55 to limit their intake of selenium to the recommended dietary allowance (RDA) of 55 mcgs.

The SELECT findings on selenium don’t mean that antioxidants have no role to play in preventing cancer or slowing its spread. Some antioxidants may be helpful but some may encourage small cancers to grow larger.  A 2014 study by researchers in the U.K. tested the effect of Pomi-T, a supplement that contains broccoli, pomegranate, green tea, and turmeric on the health of men with prostate cancer. After six months, they found that the men taking Pomi-T had a smaller increase in PSA, a protein that becomes elevated with prostate cancer, as compared to men with prostate cancer who didn’t take Pomi-T. The researchers suggest that the unique blend of polyphenols and antioxidants in the supplement had a beneficial effect on health of these prostate cancer patients.[10]

A study published in 2016 brought yet another antioxidant, vitamin D, into the prostate cancer discussion. Vitamin D is well known for its role in helping build strong bones and teeth, but it may also contribute to the fight against cancer (read more here AND here). The prostate cancer study looked at the levels of vitamin D in men who had their prostates removed due to cancer. They found that men who had the most aggressive forms of prostate cancer had lower levels of vitamin D in their blood compared to men with less aggressive forms of cancer.[11] It is not yet known whether higher levels of vitamin D prevent more aggressive forms of prostate cancer or if aggressive prostate cancer lowers levels of vitamin D. Since it is impossible to know if low levels of vitamin D is a cause or effect of aggressive prostate cancer, and since high levels of vitamin D can be dangerous, more research is needed before experts will know if men diagnosed with prostate cancer should try to take more vitamin D.

Bottom Line: We need studies to determine exactly how diet and dietary supplements can be used to prevent prostate cancer and slow its spread. Meanwhile, men should reduce saturated fats as much as possible. While the jury is still out on phytoestrogens, men may benefit from eating more soy products—especially if they are eating them in place of red meat!

For more on cancer and antioxidants, read here.

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

  1. American Cancer Society. Key Statistics for Prostate Cancer. Cancer.org. https://www.cancer.org/cancer/prostate-cancer/about/key-statistics.html. Updated 2020.
  2. Narita, S., Nara, T., Sato, H., Koizumi, A., Huang, M., Inoue, T., & Habuchi, T. (2019). Research evidence on high-fat diet-induced prostate cancer development and progression. Journal of clinical medicine, 8(5), 597.
  3. Ma R, Chapman K. A systematic review of the effect of diet in prostate cancer prevention and treatment. Journal of Human Nutrition and Dietetics. Vol (22)2009:187-199.
  4. Ganry O. Phytoestrogens and prostate cancer risk. Preventive Medicine. Vol (41) 2005:1-6.
  5. Ward H, Chapelais G, Kuhnle GC, Luben R, Khaw KT, Bingham S. Lack of Prospective Associations between Plasma and Urinary Phytoestrogens and Risk of Prostate or Colorectal Cancer in the European Prospective into Cancer-Norfolk Study. Cancer Epidemiology Biomarkers & Prevention Vol (17) 2008: 2891-2894.5
  6. Bosland MC, Kato I, Zeleniuch-Jacquotte A, Schmoll J, Rueter EE, Melamed J, Kong MX, Macias V, Kajdacsy-Balla A, Lumey LH, Xie H, Gao W, Walden P, Lepor H, Taneja SS, Randolph C, Schlicht MJ, Meserve-Watanabe H, Deaton RJ, & Davies JA. Effect of soy protein isolate supplementation on biochemical recurrence of prostate cancer after radical prostatectomy. JAMA 2013; 310(2): 170-178. doi: 10.1001/jama.2013.7842
  7. Duffield-Lillico AJ, et al. Baseline characteristics and the effect of selenium supplementation on cancer incidence in a randomized clinical trial: A summary report of the Nutritional Prevention of Cancer Trial.Cancer Epidemiology, Biomarkers, and Prevention. Vol (11) 2002: 630-639.
  8. Kristal AR, et al., Baseline Selenium Status and Effects of Selenium and Vitamin E Supplementation on Prostate Cancer Risk.  Journal of the National Cancer Institute, 2014.
  9. Chan JM et al. Plasma Selenium, Manganese Superoxide Dismutase, and Intermediate-or High-Risk Prostate Cancer. Journal of Clinical Oncology. Vol (27) 2009: 3577-3583.
  10. Thomas, R., Williams, M., Sharma, H., Chaudry, A., & Bellamy, P. (2014). A double-blind, placebo-controlled randomised trial evaluating the effect of a polyphenol-rich whole food supplement on PSA progression in men with prostate cancer—the UK NCRN Pomi-T study. Prostate Cancer and Prostatic Diseases, 17(2), 180-186.
  11. Nyame Ya, et al. Associations between serum vitamin D and adverse pathology in men undergoing radical prostatectomy. J Clin Oncol. 2016 Feb 22.

Breast implants and mammography: what we know and what we don’t know

Breast Cancer, Prevention, Uncategorized, ,
Elizabeth Santoro, RN, MPH and Dr. Diana Zuckerman

There has been a lot of attention given to mammography screening in recent years. Some of this information has been confusing to women—at what age should I first have a mammogram, how frequently should I have repeat mammograms, and are mammograms even effective? These are questions that women both with and without breast implants have been trying to understand. Despite this confusion, the U.S. Preventive Services Task Force recommends screening every two years for women ages 50-74 who have an average risk of breast cancer. Women at high risk because of family history, BRCA gene mutations, or other reasons should discuss a screening schedule with their doctor.  But, what does this mean for women who have breast implants? Are women with breast implants faced with different risks when undergoing a mammography screening? Will women with implants require special considerations during the procedure?

Delayed Breast Cancer Detection

Breast implants can interfere with the detection of breast cancer, because the implants can obscure the mammography image of a tumor. Implants therefore have the potential to delay the diagnosis of breast cancer. Although mammography can be performed in ways that minimize the interference of the implants, as described below, Miglioretti and her colleagues found that even so, 55% of breast tumors were missed, compared to 33% of tumors for women without implants.1  They also found that among newly diagnosed breast cancer patients who did not have any symptoms, the augmented women had larger tumors than those who did not have implants.

What is the impact of this possible delay in diagnosis?  Research findings have been inconsistent, but a 2013 Canadian systematic review of 12 studies found that women with breast cancer who had breast implants are diagnosed with later-stage cancers than women with breast cancer who did not have implants.2

A delay in diagnosis could result in the woman needing more radical surgery or the delay could be fatal.  A 2013 Canadian meta-analysis of five studies found that if women who had breast augmentation later developed breast cancer, they were more likely to die from it than women diagnosed with breast cancer who did not have breast augmentation.3

These studies indicate that for an individual woman, a delay in diagnosis could potentially result in death, and more research is needed to determine how often that happens, and under what circumstances. From a public health perspective, delays in diagnosis could potentially necessitate more radical surgery: a cancer that could have been treated at an earlier stage with breast-sparing treatments, such as lumpectomy, may instead require a mastectomy.3,4

What are the other possible problems that implants can cause regarding mammography?

A study by FDA scientist Dr. S. Lori Brown and colleagues describes problems that were reported to the FDA related to breast implants and mammography screening.5 The authors found 66 adverse events that were reported as either occurring during the mammogram or involving breast implants interfering with the mammogram. Forty-one reports of either silicone or saline breast implants- – almost two out of three reports– pertained to ruptures that were suspected as happening during mammography. The other 25 reports included delayed breast cancer detection, inability to perform the mammogram due to capsular contracture or because of fear that the implant would rupture, and pain/soreness during and after the procedure.

Description of the FDA Study

This study examined data from the Manufacturer and User Facility Device Experience (MAUDE) database. This FDA database collects mandatory or voluntary reports of medical device adverse events from physicians, breast implant manufactures, consumers, and others. The reports were received between June 1992 and October 2002 for events that occurred between June 1972 and June 2002. The mean age of the implant was 14.5 years, and ranged from 2-29 years.

The use of the MAUDE database has limitations. The FDA does not verify the information that is provided. Therefore, the FDA cannot guarantee that the information is accurate and complete. In addition, in some cases, a doctor and a patient could potentially report the same problem.  On the other hand, most problems are not reported even once, since patient and physician reporting is voluntary. It is well-documented that the vast majority of problems arising from medical products are not reported to the FDA. As a result of these shortcomings, these data cannot be used to calculate the number of new adverse events expected for a given number of people in a defined time period.

Key Implications of the Studies on Implants and Mammograms

Potential Implant Rupture

The FDA warns that all implants will eventually break, and research shows that most women who have implants for ten years or longer will have at least one broken implant.6 The risk of breast implant rupture is known to increase as the implant ages. A study by Holmich and colleagues suggested that during the first ten years a woman has implants, most implants do not break, between 11-20 years most will break, and by the time they are more than 20 years almost all have broken.7 Women with implants have been told that mammography is safe for them, but the results of the Brown study suggest that the risk of rupture can be exacerbated by mammography.

Brown and her colleagues also reviewed the published research on implant rupture during mammography and found an additional 17 cases reported in medical journals. According to the American Society of Plastic Surgery, approximately half of the women who get breast implants are in their 20′s or early 30′s,8 which means that the implants are already broken or vulnerable by the time these women are old enough for screening mammograms.

Mammography may therefore increase the risk of a rupture earlier in the typical lifespan of implants, and the squeezing involved in mammography probably increases the risk of leakage in implants that are already ruptured. The potential risk of rupture or leakage needs to be weighed against the benefits of mammography by each individual woman. For women who are concerned about breast cancer, knowledge of mammography problems might discourage women from getting breast implants, or encourage them to have their implants removed and not replaced. Current guidelines encourage women with breast implants to have regular mammograms provided that the technician knows the woman has implants prior to the procedure and that special techniques are utilized.6 In light of this new research, those guidelines need to be reconsidered, especially for women with silicone gel breast implants, where leakage can cause permanent disfigurement and has unknown health risks.

Avoidance of Mammography

The Brown study also found that implants sometimes make it impossible to perform a mammogram. This can happen for two reasons. First, conditions such as capsular contracture, where the scar tissue around the implant tightens and causes the breast to become hard and misshapen, can make it very difficult or even impossible to perform the mammogram.9, 10 The compression of the breast that is required in order to perform the mammogram can be extremely painful if there is capsular contracture, and in some cases the hardness of the breast makes it impossible to compress the breast for the mammogram. Some women avoid getting mammograms because they are afraid of rupture and the latest research indicates that this is a reasonable concern.

Biomaterials testing of breast implants indicates that implants should only break under the most traumatic circumstances, and yet implants break for no apparent reason, as well as under pressure from mammograms.11 It is difficult to know how much risk a mammogram increases the risk of rupture since so little is understood about why implants break and under what circumstances.

What Does this Mean for Women?

Women considering breast implants and women with breast implants need to be informed consumers, and that includes knowing about the problems that arise from having mammograms with breast implants. This is true for all women, but especially breast cancer patients who may use implants on a healthy breast so that it will match the reconstructed breast after a mastectomy. (Detection of cancer in the reconstructed breast is unlikely to be a problem because mammography is not used after a mastectomy. Since breast cancer survivors are at greater risk for breast cancer in the breast that was not removed, compared to women who have not had breast cancer, survivors should have regular mammograms of the surviving breast, and need to know the risks.

Women with breast implants and those considering breast implants need to know that they will have a different mammography experience than women without implants, to try to improve the accuracy. The special techniques used will push the implant back to try to move it out of the way, and extra views will be taken. Even so, as reported earlier in this article, mammograms performed on women with implants will still miss more tumors than is typical of mammograms for women who do not have implants.7, 12 In addition, women with implants should expect that mammography will require more views and take longer, thus costing more and exposing them to increased levels of radiation. Unfortunately, the most common problem, capsular contracture, can make mammography more painful, less accurate, or even impossible to perform. In such cases other, more expensive tests, such as an MRI or ultrasound, may be required.

Women also need to understand that even if breast implants do not cause contracture or other problems, they will still interfere with mammography and mammograms might still cause rupture and leakage.

The bottom line is that women considering breast implants and those who already have them need to be informed about potential problems with mammography so that they can make the decisions that will help them reduce the risk of breast cancer and avoid the problems that arise with implant breakage and leakage.

For more information on breast implants, see www.breastimplantinfo.org.

Related Content:
What you need to know: Breast cancer, suicide, mastectomy, and breast implants
Summary of: Breast Implants, Self-Esteem, Quality of Life, and the Risk of Suicide
2016 Update: When should women start regular mammograms? 40? 50? And how often is “regular”?

 

Can a handful of nuts a day keep cancer away?

Breast Cancer, Colon Cancer, Diet, Habits, & Other Behaviors, Ovarian Cancer, Pancreatic Cancer, Prevention, , ,
By Krista Kleczewski, Claire Karlsson, and Edyth Dwyer

Evidence is growing about the many ways in which eating nuts, seeds, and legumes can improve your health. Eating walnuts or legumes like peanuts, beans, or lentils have been linked to healthier hearts and a lower risk of diabetes, but now studies show they may also cut your risk of getting cancer! Here’s what we know and don’t know.

In addition to erroneously thinking that peanuts are nuts, many people think almonds, cashews, and pecans as nuts, but they are actually types of seeds. The difference is based on the plant they grow on, where peanuts grow underground below the plant roots, nuts and seeds grow inside or outside the plant’s fruit. Although this article uses the term “nuts,” the studies we describe include many combinations of nuts, seeds, and legumes. It’s also important to note that each study has different methods, and they need to be interpreted differently. Some studies looked at fewer than 100 people and closely tracked their diet and health, while others were meta-analyses that collected results from many studies of thousands of people and summarized their findings. 

What are some health benefits of nuts?

 In 2015, a Dutch study of 120,000 men and women between the ages of 55-69 found that those who ate about half a handful of nuts or peanuts each day were less likely to die from respiratory disease, neurodegenerative diseases, diabetes, cardiovascular diseases, or cancer than those who consumed no nuts or seeds.[1] The same benefit was not seen for peanut butter, however, which suggests that the salt, vegetable oils, and trans fatty acids in peanut butter may counterbalance the benefits of the peanuts. A serving of nuts is about the size of 30 almonds, and a study found that eating several servings a week had health benefits. A 5-year study conducted in Spain of 7,000 men and women aged 55 to 80 years old found that eating at least three servings of nuts per week reduced the risk of cardiovascular and cancer death.[2] Another study similarly found eating nuts – especially walnuts — reduces the risk of developing cancers, diabetes and heart disease when eaten as a part of the Mediterranean Diet, which also emphasizes fruits, vegetables, whole grains, and legumes.[3] Walnuts were highlighted by the study as reducing inflammation associated with certain cancers and other conditions like diabetes and heart disease. More evidence is needed, however, to determine the specific impact of walnuts on cancer risk.

Breast Cancer

Eating large amounts of peanuts, walnuts, or almonds can reduce the risk of developing breast cancer, according to a 2015 study of 97 breast cancer patients.[4] The researchers compared the lifetime consumption of peanuts, walnuts and almonds among breast cancer patients with the consumption of those without breast cancer, finding that women who ate large quantities were half to one-third as likely to develop breast cancer. No difference was found between people who ate a small amount of nuts, legumes and seeds and those who ate none at all, suggesting that a person needs to consume a substantial amount of these over their lifetime to reduce their chances of developing breast cancer.

Another study looked at the risk of breast cancer for people who ate nuts and peanuts compared to people who did not. Some types of breast cancers respond to the body’s natural hormone estrogen, growing faster when exposed to estrogen. These are called Estrogen Receptor (ER) positive cancers. ER negative cancers are not influenced by exposure to estrogen. In a study of over 4,000 women in the Netherlands, those who ate 10 grams (a large handful) of nuts per day had a 45% lower risk of developing ER negative breast cancer when compared to those who ate no nuts, but it did not significantly affect ER positive breast cancer.[5,6] Since ER negative breast cancer occurs in only a third of the 12% of women who are diagnosed with breast cancer, the risk to the average person decreased overall by about half of 1% when their diet included that many nuts. 

Girls who regularly eat nuts in their diet may be less likely to develop breast cancer as adults. A 2020 study of more than 9,000 girls between the ages of 9-15, and found that girls who regularly ate peanut butter or any kind of nuts were 36% less likely than girls who did not to have developed benign breast conditions when followed up with 10 years later. Although not dangerous, benign breast conditions (such as breast cysts or hyperplasia) increase a woman’s chances of eventually getting breast cancer. [7]

Can eating nuts, legumes and seeds reduce colorectal cancer risk?

To find out whether snacking on foods with peanuts lowers your chances of getting colorectal cancer (also called colon cancer), researchers studied more than 23,000 adults in Taiwan, ages 30 and older.[8] The researchers reported in 2006 that women who ate meals with peanut products at least twice each week were less likely to develop colorectal cancer. More research is needed to see if this benefit is actually from the peanuts.

A 2021 meta-analysis collected results from over 40 studies, and it examined whether eating more nuts would have an impact on colon cancer risk. Researchers found that eating 5 grams of nuts per day could decrease the risk of colon cancer by 25%.[9] Since the lifetime risk of colon cancer is about 4%, a 25% reduction would mean a decrease from 4% to 3% of the overall risk of colon cancer for people regularly eating nuts. Five grams is about 5-6 almonds, and this study found that the benefits of eating nuts started for people averaging just 2 grams per day and continued to decrease for people eating up to 9 grams per day.  After that, the effects leveled off, so eating more than 9 grams was not more beneficial than eating 9 grams. A meta-analysis combines results from many studies, so the 2-9 grams per day were average amounts, whether the person eats them all in one day or spread out over the course of a week. 

In one of the largest studies of diet and cancer, which was conducted in 10 European countries, researchers discovered that eating nuts and seeds reduced women’s chances of developing colon cancer, but did not lower the risk for men.[10] Women who ate a modest daily amount of nuts and seeds (about 16 peanuts or a small handful of nuts or seeds) every day were less likely to develop colon cancer, and women who ate the largest quantities of these foods were the least likely to develop colon cancer. Again, more research is needed to understand these findings.

Researchers have also investigated whether a diet containing nuts and peanuts can improve patient chances of survival for those who have already been diagnosed with colon cancer. In a study of over 800 patients with advanced (stage III) colon cancer, patients who ate more nuts were more likely to survive after treatment, without being re-diagnosed with colon cancer.[11] This study measured a serving of nuts to be one ounce, or about 15 cashews. When compared to those who ate no nuts, those who ate 2 or more servings of nuts per week had 46% lower risk of re-diagnosis of their cancer, as well as a 53% lower risk of dying from the cancer. This study has several important limitations to keep in mind. Not only was it a relatively small study, but it only examined Stage III colon cancer patients, comparing cancer patients who ate nuts to those who did not eat nuts. This means that the results cannot be generalized to the average American’s risk of colon cancer. 

Pancreatic Cancer

Eating nuts also seems to lower the risk of developing diabetes, which may then lower the risk of developing pancreatic cancer.[12] In addition, a large study of women found that frequently eating nuts was associated with less chance of developing pancreatic cancer,13 one of the most deadly cancers.

A 2021 meta-analysis that examined results from over 30 studies, found that the chances of developing pancreatic cancer risk decreased for those who ate more nuts. The average lifetime risk of developing pancreatic cancer is about 1.5%. Because the results show a 6% lower risk for those eating nuts, this means the overall risk of pancreatic cancer may lower from 1.5% to 1.4% for people who regularly eat nuts.[9]

Ovarian cancer

A 2010 study examined the possible link between ovarian cancer and foods high in phytoestrogens and/or fiber, including nuts, beans, and soy.[15] They found that these foods seemed to help prevent “borderline ovarian cancer”—slow-growing tumors that are less dangerous and more likely to affect younger women. However, these foods did not seem to protect against the more aggressive types of ovarian cancer.

What makes nuts good for your health?

There is still some debate about why nuts might be so beneficial. Omega-3 fatty acids are found in peanuts, walnuts, and some seeds, and researchers think their health benefits may help to prevent cancer.[16] The omega-3 acids can help protect cell structures and walls, and since they are anti-inflammatory; that might reduce the risk of cancer for people who regularly eat peanuts, walnuts, and seeds. [17]

Some research has shown that walnuts can also improve your gut biome, meaning it helps you grow healthy bacteria in your gut.[18]  To test this, an experiment was done on 18 people, where some were assigned to eat walnuts and others ate no nuts. Blood and fecal samples were tested, and researchers were able to see changes in the bacteria, and lower levels of “secondary bile” which suggests the nuts decreased inflammation in their intestines. This experiment studied a very small group of people, so more research is needed to understand why these nuts, seeds, and legumes improve the risk of cancer over a lifetime. 

 

The Bottom Line

There is growing evidence that nuts, legumes, and seeds reduce the risk for several types of cancer, as well as having other health benefits. Researchers are still investigating whether the health benefits of nuts are because people who eat nuts have a healthier overall diet, but tree nuts seem to have some health benefits on their own. Peanuts and peanut butter may also have benefits, but the higher levels of fat and sodium could explain why these legume products show fewer health benefits. Peanuts, walnuts, almonds, and other nuts are high in calories, so don’t overdo it. It seems safe to assume that adding these foods to your diet, in small quantities several times a week, is a good idea, especially if you use them to replace less healthy snacks.

 

 

 

  1. Brandt, P., & Schouten, L. Relationship of tree nut, peanut and peanut butter intake with total and cause-specific mortality: A cohort study and meta-analysis. (2015). International Journal of Epidemiology, 44(3), 1038-1049. doi:10.1093/ije/dyv039  
  2. Guasch-Ferré, M., Bulló, M., Martínez-González, M.A., Ros, E., Corella, D., et al. Frequency of nut consumption and mortality risk in the PREDIMED nutrition intervention trial. (2013). BMC Med; 11: 164. doi: 10.1186/1741-7015-11-164  
  3. Toner, CD., Communicating clinical research to reduce cancer risk through diet: Walnuts as a case example (2014). Nutr Res Pract. 8(4): 347–351. doi: 10.4162/nrp.2014.8.4.347  
  4. Soriano-Hernandez, A.D., Madrigal-Perez D.G., Galvan-Salazar H.R., Arreola-Cruz A., Briseño-Gomez L., Guzmán-Esquivel J., Dobrovinskaya O., Lara-Esqueda A., Rodríguez-Sanchez I.P., Baltazar-Rodriguez L.M., Espinoza-Gomez F., Martinez-Fierro M.L., de-Leon-Zaragoza L., Olmedo-Buenrostro B.A., Delgado-Enciso I. (2015). The Protective Effect of Peanut, Walnut, and Almond Consumption on the Development of Breast Cancer. 2015;80(2):89-92. doi: 10.1159/000369997.  
  5. van den Brandt P.A., Nieuwenhuis L. Tree nut, peanut, and peanut butter intake and risk of postmenopausal breast cancer: The Netherlands Cohort Study. Cancer Causes Control, (2018). 29(1):63–75.
  6. Putti T.C., El-Rehim D.M.A., Rakha E.A., Paish C.E., Lee A.H.S., Pinder S.E., et al. Estrogen receptor-negative breast carcinomas: a review of morphology and immunophenotypical analysis. (2005). Mod Pathol, 18(1):26–35.
  7. Berkey C.S., Tamimi R.M., Willett W.C., Rosner B., Hickey M., Toriola A.T., et al. Adolescent alcohol, nuts, and fiber: combined effects on benign breast disease risk in young women. (2020). NPJ Breast Cancer;6(1):61.
  8. Yeh, C. C., You, S. L., Chen, C. J., & Sung, F. C. Peanut consumption and reduced risk of colorectal cancer in women: a prospective study in Taiwan. (2006). World Journal of Gastroenterology, 12(2), 222.  
  9. Naghshi, S., Sadeghian, M., Nasiri, M., Mobarak, S., Asadi, M., Sadeghi, O. Association of total nut, tree nut, peanut, and peanut butter consumption with cancer incidence and mortality: A comprehensive systematic review and dose-response meta-analysis of observational studies. (2021). Adv Nutr, 12(3):793–808.
  10. Jenab, M., Ferrari, P., Slimani, N., Norat, T., Casagrande, C., Overad, K., Riboli, E. et al. Association of nut and seed intake with colorectal cancer risk in the European Prospective Investigation into Cancer and Nutrition. (2004). Cancer Epidemiology Biomarkers & Prevention, 13(10), 1595-1603.  
  11. Fadelu T., Zhang S., Niedzwiecki D., Ye X., Saltz L.B., Mayer R.J., et al. Nut consumption and survival in patients with stage III colon cancer: Results from CALGB 89803 (alliance). (2018). J Clin Oncol,36(11):1112–20.
  12. Jenkins, D. J., Kendall, C. W., Banach, M. S., Srichaikul, K., Vidgen, E., Mitchell, S., Josse, R. G., et al. Nuts as a replacement for carbohydrates in the diabetic diet. (2011). Diabetes care, 34(8), 1706-1711.  
  13. Bao, Y., Hu, F. B., Giovannucci, E. L., Wolpin, B. M., Stampfer, M. J., Willett, W. C., & Fuchs, C. S. Nut consumption and risk of pancreatic cancer in women. (2013). British journal of cancer.  
  14. Lee J.T., Lai G.Y., Liao L.M., Subar A.F., Bertazzi P.A., Pesatori A.C., et al. Nut consumption and lung cancer risk: Results from two large observational studies. (2017). Cancer Epidemiol Biomarkers Prev,26(6):826–36.
  15. Hedelin, M., Löf, M., Andersson, T. M. L., Adlercreutz, H., & Weiderpass, E. Dietary phytoestrogens and the risk of ovarian cancer in the women’s lifestyle and health cohort study. (2011). Cancer Epidemiology Biomarkers & Prevention, 20(2), 308-317.  
  16. Fabian C.J., Kimler BF, Hursting S.D.. Omega-3 fatty acids for breast cancer prevention and survivorship. (2015) Breast Cancer Res;17(1):62. https://breast-cancer-research.biomedcentral.com/articles/10.1186/s13058-015-0571-6
  17. Freitas R.D.S., Campos M.M.. Protective effects of omega-3 fatty acids in cancer-related complications. (2019). Nutrients;11(5):945. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6566772/#:~:text=Omega%2D3%20polyunsaturated%20fatty%20acids,structure%20and%20fluidity%20of%20membranes
  18. Holscher H.D., Guetterman H.M., Swanson K.S., An R., Matthan N.R., Lichtenstein A.H., et al. Walnut consumption alters the gastrointestinal Microbiota, microbially derived secondary bile acids, and health markers in healthy adults: A randomized controlled trial. (2018). J Nutr;148(6):861–7.

Children and Cell Phones: Is Phone Radiation Risky for Kids?

Brain Cancer, Environmental Exposures, Prevention, , , , ,
Hannah Kalvin

Children use cell phones to watch TV, play games, make phone calls, and send text
messages.  Many older kids and teens have their own cell phones, which they are attached to kid texting24/7. But are there risks to such frequent use by children, and if so is that different than the risks for adults?

Cell phones emit a type of radiation that is known as Radio Frequency-Electromagnetic Radiation (RF-EMR), also referred to as microwave radiation. There have been concerns from the scientific community about whether or not cell phones are safe. Cancer is a particular concern, but since cancers take 10-20 years to develop and children’s frequent cell phone use is a relatively recent development, there are more questions than answers.  To read more about whether we should be worried about cell phone radiation in general, read our article here.

There are several studies of the impact of cell phone radiation on children. Here are some of the conclusions so far:

  • A 2010 study of cell phone radiation noted that, “in general and on average, children suffer a higher exposure of their brain regions than adults.”  This is because children have proportionally smaller heads and brains, yet receive the same levels of cell phone radiation as adults.13 The American Academy of Pediatrics agrees, saying that “when used by children, the average RF energy deposition is two times higher in the brain and 10 times higher in the bone marrow of the skull, compared with mobile phone use by adults.”14
  • Another study found that people who begin using cell phones (and cordless landline phones) before the age of 20 are at an even higher risk of developing brain tumors than people who begin using these wireless phones as adults.15,16 This is because of the closer proximity of the source of radiation to the brain of kids (they have thinner tissues and bones than adults).
  • Research also suggests that cell phone exposure could affect children’s behavior.17 The children in the study who were hyperactive or had emotional or behavioral problems, including trouble getting along with other kids, were much more likely to have mothers who used cell phones during pregnancy. After accounting for other factors that could affect behavior, the children of these mothers were 80% more likely to have behavioral problems than children whose mothers rarely or didn’t use cell phones. However, this is difficult to study because mothers who use cell phones frequently during pregnancy or after the baby is born, may pay less attention to their children, resulting in the children’s bad behavior. More research is needed to understand the link between mother’s cell phone use and children’s behavior.
  • Children that used cell phones more were more likely to have ADHD. Although the link to ADHD was only for children who also had high levels of lead in their blood, when researchers adjusted for blood lead level, they still found that ADHD was more likely for children who made more phone calls and spent a longer amount of time on the phone.18 This study was conducted in Korea, so it would be important to do similar research on children living in other countries.
  • A 2014 article reviewing studies on children and their cell phone use found that the younger the child, the greater the risk of brain cancer and brain tumors. The same article also points to studies concluding that cell phones are associated with an increased risk of breast cancer (due to adolescents putting cell phones in their bras), parotid (salivary) gland tumors, and sperm damage for adolescents and adults.19

Reactions To Research About Cell Phone Radiation

In 2012, the American Academy of Pediatrics wrote a letter to the Federal Communications Commission, which sets the standards for cell phone radiation in the United States, and recommended that they reevaluate these standards since this had not been done since 1996. Their reasoning is that “children, however, are not little adults and are disproportionately impacted by all environmental exposures, including cell phone radiation.”2 But, as of 2015, the FCC still says that there is no evidence between wireless device use and health problems and continues to uphold the regulations from 1996.20 Other countries have taken a different approach. As of 2014, Turkey, Belgium, Australia, and France have warned about the dangers of children’s cell phone usage.7

 

Conclusions

Scientists disagree on whether cell phone radiation can cause cancer or other health problems.  Since so many children and adults use cell phones so frequently, that makes it difficult to do a study comparing high and low cell phone usage.  And since brain tumors and other cancers usually do not develop until several decades after the initial exposure, it could be years before we know how risky cell phones are and under what circumstances.7

By the time we find out, many people will have been harmed if cell phones are found to be dangerous. Here are some precautionary tips on how to protect your children from the health issues that could be connected to cell phone radiation.21

  1. Turn airplane mode on when giving a child a technology device or when a cell phone is near a pregnant abdomen, to prevent exposure to radiation.
  2. Turn off wireless networks and devices to decrease your family’s radiation exposure whenever you aren’t actively using them. As an easy first step, turn your Wi-Fi router off at bedtime.
  3. Decrease use of phones or wifi where wireless coverage is difficult, in order to avoid an increase in radiation exposure.
    The warning about RF exposure found on an iPhone 5s.
    The warning about RF exposure found on an iPhone 5s.
  4. Use the speaker phone or a plug in earpiece when you use a cell phone. To protect children from radiation, they should not use cell phones except in emergency and should use the speaker phone.
  5. Increase the distance between you and your cell phone whenever it is on, to reduce your exposure to radiation emitted. For example, do not use a cell phone while a child is on your lap, and do not carry your cell phone in your baby carrier, crib, or pockets. When the phone is on, tell your kids to put it in a backpack as far from their body as possible (such as an outside pocket) or on the desk or other furniture at home, instead of holding it or carrying it in a pocket.
  6. Read the fine print: All device manufacturers advise that cell phones should be at least 5 millimeters, or about ¼ of an inch away from your body or brain. With the iPhone 6 and the iPhone 6s, the company advises users to keep the cell phone at least 10 millimeters, or about half an inch, away from your body or brain. See the safe distance for your phone. For iPhone 5 and iPhone 6, this is located under: Settings -> General -> About -> Legal -> RF Exposure.
  7. Share this info with your friends, family, and schools so that they can make these simple changes as well.

 

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

Tanning beds: safe alternative to sun?

Diet, Habits, & Other Behaviors, Environmental Exposures, Prevention, Skin Cancer
By Heidi Mallis, B.A and Diana Zuckerman, PhD
Updated 2015

For many years, tanning beds were advertised as a safe alternative to a natural suntan, but in fact, there was no evidence that was true.  No U.S. government agency evaluated sun lamps, tanning beds, or tanning booths to make sure they were safe.  As a result, nearly 30 million people in the U.S. were using tanning beds each year22, 2.3 million of whom were adolescents.23

Research evidence was growing about the risks of tanning beds.  According to the American Academy of Dermatology and the World Health Organization, indoor tanning increases a person’s chances of developing melanoma by 59 percent, and the risk goes up with each use.24

Finally, in 2014 the U.S. Food and Drug Administration (FDA) announced that all sun lamps and UV lamps intended for use in sun lamp products must come with warnings include the following:

  • This product is contraindicated for persons under the age of 18 years;
  • This product must not be used if skin lesions or open wounds are present;
  • This product should not be used on people who have had skin cancer or a family history of skin cancer
  • People repeatedly exposed to UV radiation should be regularly evaluated for skin cancer3

As evidence grew of the link between tanning beds and skin cancer, especially for men and women in their 20s, more than 60% of states passed some kind of legislation restricting the use of tanning salons by children under 18 and two states, California and Vermont, have passed complete bans of indoor tanning for minors.25

What does this mean for you?

Tanning beds expose the user to a lot of artificial UV radiation in a short period of time. Just one 8-20 minute session exposes a person to more UV radiation than an entire afternoon spent in natural sunlight. In fact, doses of UV radiation emitted by high pressure sunlamp products may be up to 10 to 15 times higher than that of the midday sun, which is more intense than UV radiation found in nature.

A study conducted by Dr. S. Elizabeth Whitmore and Dr. Warwick Morison of Johns Hopkins University School of Medicine found that ten tanning sessions in two weeks produced evidence of a suppressed immune system among participants. This means that the body is less capable of fighting off infectious agents.26 Tanning bed use is also associated with faster skin aging because the UV radiation destroys skin fibers and damages elasticity. Characteristics of skin aging include wrinkles, dark spots, and a leathery texture.27

The International Agency for Research on Cancer lists tanning beds in its highest cancer risk category, “carcinogenic to humans.” This means that there is enough evidence to conclude that tanning beds can cause cancer in humans. Prior to 2009, the agency, which is part of the World Health Organization (WHO), previously classified tanning beds as “probably carcinogenic.” The change came after an analysis of more than 20 epidemiological studies indicating that people who begin using tanning devices before age 30 are 75% more likely to develop cutaneous melanoma, the most serious type of skin cancer28

Skin cancer is the most common form of cancer, with more than one million cases diagnosed each year in the U.S. There are three types of skin cancer: squamous cell, basal cell, and melanoma. Squamous cell carcinomas typically occur on surfaces exposed to the most sunlight, such as the ears or face. This type of skin cancer can spread quickly to other organs in the body. Basal cell carcinomas account for 8 out of 10 skin cancers. They grow very slowly and rarely spread to other parts of the body (as a result, they are highly treatable). Melanomas are the third and most dangerous type of skin cancer. They are less common than basal and squamous cell carcinomas but much more serious.29 Melanomas usually present as a change to an existing mole or an entirely new mole that is black or has a blue-black area. Their diameter is typically larger than that of a pencil eraser. If caught early, melanomas are often completely curable. However, they are much more likely to spread to other parts of the body if not found early.30

Risk factors for all three types of skin cancer include:

  • Lifetime exposure to UV radiation (from natural or artificial sources)
  • Family history of skin cancer
  • Geographic location (people who live close to the equator as well as in the mountains are exposed to higher levels of UV radiation)
  • Fair skin that freckles or burns easily
  • Severe sunburns as a child
  • Radiation therapy

Here are a few ways to lower your risk and avoid wrinkles and other skin damage:

  • Avoid direct sun exposure during midday hours (from 10 am-4 pm),
  • Use sunscreen with a sun protection factor (SPF) of at least 15
  • Regularly check your skin for any new moles, sores, or scaly patches (and visit a dermatologist if you notice the lesion changing form or color), and
  • Avoid using a tanning bed or booth (especially if you are a child, teenager, or young adult).31

Keeping track of moles and other changes to your skin are an easy way to improve your skin health. However, the U.S. Preventive Services Task Force suggests that if you are not at an increased risk of developing skin cancer, there is no need for yearly skin checks by a dermatologist.32

Continue to monitor any existing or new moles and contact your doctor if you detect any significant changes in size, shape, or color.

 

Running and skin cancer prevention

5K, Events, Prevention, Skin Cancer
By Danielle Pavliv
2015

Exercise reduces your risk of cancer and many other diseases, but running outdoors can increase your risk of skin cancer if you don’t follow a few simple rules.

Running is one of the most popular forms of exercise. It can be done anywhere, doesn’t require a gym or any special equipment (although some people prefer to use a treadmill)-just a good pair of shoes and comfortable clothing. Running outside — whether on a track, in the woods, or on a path by the river — can be a wonderful and restorative way to exercise. Nature and exercise are both great ways to improve your mood.

Running regularly can lower the risk of many health problems including heart disease, stroke, osteoporosis and bone fracture, diabetes, and obesity.[end Warburton DE, Nicol CW, Bredin SS. Health benefits of physical activity: The evidence. Canadian Medical Journal. 2006; 174(6):801-809.] In addition, it can improve mental health and blood pressure.[end Paluska SA, Schwenk TL. Physical activity and mental health: Current concepts. Sports Medicine. 2000;29(3):167-180.] However, many people don’t take proper precautions when they decide to go running outside, and the results can be deadly.

Imagine this: it’s a nice day outside, so you decide to go for a jog, wearing running shorts and a t-shirt. You probably don’t spend too much time thinking about what to wear — you simply notice what the temperature is, put on something comfortable, and go. Sunscreen seems like a hassle, and you think you’ll probably sweat it off anyway. It’s not like you will be laying out at the pool or playing golf all day, so how much harm can a 30-minute run cause anyway?

While many of us try to protect our skin when spending time outside, data show that just over half of all American adults usually take at least one of these three precautions:  seeking shade, using sunscreen, or wearing sun-protective clothing.[end Sun-Protective Behavior Rates. Skin Cancer. Centers for Disease Control and Prevention. August 2011. Available at: http://www.cdc.gov/cancer/skin/statistics/behavior.htm.] People who don’t do any of these are at much higher risk for skin cancer.

Skin cancer

Skin cancer is the most common of all cancers. In the U.S., accounting for almost half of all cancers and affecting over 2 million people each year. One in 5 Americans will develop skin cancer during their lifetime.[end Robinson JK. Sun exposure, sun protection, and vitamin D. Journal of the American Medical Association. 2005;294(12):1541-1543.] There are three types of skin cancer: basal cell, squamous cell, and melanoma. Basal cell carcinomas are the most common type of skin cancer. They rarely spread to other areas of the body, and are very treatable. Squamous cell carcinomas, on the other hand, can spread to organs and other areas in the body and can be fatal if they are not caught early. The third type of skin cancer, melanomas, are the least common but most dangerous — they kill more than 8,600 Americans every year.[end Skin Cancer Statistics. Centers for Disease Control and Prevention. April 2012. Available at: http://www.cdc.gov/cancer/skin/statistics/.] If found early, however, melanomas can be treated. Melanomas are most often caused by ultraviolet radiation from the sun or tanning beds. They usually resemble moles and are often black or brown. Most change over time, including an increase in size.[end National Cancer Institute. Signs and symptoms of melanoma. U.S. National Institutes of Health. January 11, 2011. Available at: http://www.cancer.gov/cancertopics/wyntk/skin/page8.] In recent years, incidence of melanoma has increased significantly, especially in those with fair skin. While melanoma is more prevalent in men than women, rates of diagnoses and death are increasing for both men and women.

Is exercising outside more risky than just relaxing outside?

In 2006, Dr. Christina Ambros-Rudolph and colleagues at the Medical University of Graz in Austria conducted a study to see if marathon runners are at higher risk of melanoma than people who don’t run as regularly.[end Ambros-Rudolph CM, Hofmann-Wellenhof R, Richtig E, Müller-Fürstner M, Soyer HP, Kerl H, Dermatol A. Malignant Melanoma in Marathon Runners. Archives of Dermatology. 2006;142(11):1471-1474.] They examined over 200 runners and found that they are at increased risk for skin cancer. In fact, runners who trained the most intensively had the highest rates of skin lesions. Almost all of the athletes wore shirts and shorts that did not totally cover their arms, back and legs, and only 56% wore sunscreen. Although there was a clear link between sun exposure and skin lesions, the researchers found another reason the athletes who had more intense workouts were more prone to skin cancer. Endurance exercise such as long-distance running suppresses immune function in the body, which is why extreme athletes are often more susceptible to infections than others. This can release a type of protein called cytokines, limiting the ability of the body’s immune system to fight off potential cancers. In addition, sweating a lot while outside is linked to skin cancer. The wetter your skin, the more UV rays are absorbed, which means that exercising on sunny days can be much more dangerous for your skin than just sitting or laying down in the sun.

How to stay safe outside

You don’t have to give up running outside — there are plenty of ways to protect yourself outside for exercise or any other activity. Try to do as many of these as possible each time you go out in order to lower your risk for melanoma or other types of skin cancer:

  • Use a generous amount of sunscreen with a sun protection factor (SPF) of 30 or higher, even on cloudy days — cloud cover only blocks out one type of UV rays. Reapply often, especially if you are sweating or in the water. Use a water-resistant sunscreen that will stay on when you swim or sweat.
  • Avoid the sun between 10 a.m. and 4 p.m., when UV rays are the strongest. If you want to go for a run outside, try to do it early in the morning or right before sunset.
  • Put on some sunglasses with high UV absorption to protect your eyes, and a hat to protect your face.
  • Wear clothes made of tightly woven fabrics that you cannot see through. Try to avoid regularly exposing areas of your body such as your shoulders, neck and chest. To prevent overheating, wear light-colored clothing that reflects the sun’s rays.
  • Look for shade: try to do your stretches and other exercises in a shaded area.

Choosing a sunscreen

The American Academy of Dermatology recommends that everyone wears a water-resistant sunscreen of at least 30 SPF daily.[end American Academy of Dermatology Sunscreen Website. Stats and Facts. Prevention and Care. Sunscreens. 2012. Available at: http://www.aad.org/media-resources/stats-and-facts/prevention-and-care/sunscreens.] Further, they recommend using a broad-spectrum sunscreen that protects against both types of UV rays (UVA and UVB). You can use the Environmental Working Group’s website to find out which sunscreen really work and don’t contain a lot of harmful and even cancer-causing ingredients. The Food and Drug Administration (FDA) didn’t regulate sunscreen until June 2012. Prior to that date, there was no guarantee that the sunscreen you were slathering on your body actually protected you or did what the label claimed. Now, manufacturers are required to label their products accurately and are held to safety and effectiveness standards.[end FDA sheds light on sunscreens. U.S. Food and Drug Administration. June 2012. Available at: http://www.fda.gov/forconsumers/consumerupdates/ucm258416.htm.] When choosing a product, remember that a sunscreen with twice the SPF does not mean you can stay outside in the sun twice as long before you get a sunburn. The intensity of UV radiation matters just as much as how long you are in the sun, which is why it’s so important that you limit your exposure from 10 a.m. to 4 p.m.[end Jou PC, Feldman RJ, Tomecki KJ. UV protection and sunscreens: What to tell patients. Cleveland Clinic Journal of Medicine. June 2012;79(6):427-436.]

Make sure to regularly check your body for any new moles or scaly patches. If they change size, form or color, visit a dermatologist. If you have skin cancer in your family, you will likely want to get your moles checked regularly.

Sun damage is permanent and irreversible, so it’s important to take good care of your skin throughout your life. Remember — a tan is a sign of skin damage. There’s no such thing as a “healthy” tan!

For more information about the most dangerous type of skin cancer, see http://dev.stopcancerfund.org/t-skin-cancer/treating-skin-cancer-melanoma/

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.

Which sunscreen should you use?

Prevention, Skin Cancer
By Isabel Platt and Laura Gottschalk, PhD
Updated 2016

Sunscreen-infographic

 

Other than the 15 minutes of sunshine we all need for our daily requirement of vitamin D, staying out of the sun should always be the first choice for skin cancer prevention.  However, there are ways to reduce the damage your skin gets from the sun. Wearing protective clothing, hats, and limiting sun exposure during the sunniest parts of the day are all great ideas. When sun exposure can’t be avoided, however, sunscreen can also help protect from some of the damaging effects of the sun.

But what kind of sunscreen is best? Spray or lotion? SPF 15 or SPF 70? Waterproof or moisturizing? It seems like new rules come out every year. To clear up mixed messages, here is a guide to choosing the best sunscreen for you and your family.

SUNSCREEN PREVENTS CANCER

Spending too much time in the sun puts you at risk for skin cancer. There are three types of skin cancer: basal cell, squamous cell, and melanoma. Basal cell cancers, the most common, are slow growing and are the easiest to treat. Squamous cell cancers detected at an early stage are curable and cause minimal damage. Melanoma is the least common but most dangerous kind of skin cancer. If not caught early, it can spread throughout the body and become fatal.

Most melanomas result from sun exposure.33 The number of men and women in the U.S. diagnosed with melanomas increased by nearly 2% each year between 2000 and 2009, and even more among Caucasians.1 34 35 If you have fair skin, you are especially likely to get melanoma from sun exposure. The easiest way to reduce your risk of melanoma is to apply sunscreen to exposed areas every day as part of your morning routine, but don’t forget that it only lasts about 2 hours so you may need to apply it again later in the day.36 If you need another reason to wear sunscreen, a 2013 study found that applying sunscreen every day reduces aging of the skin by 24%.37

Protecting your kids from sunburns is especially important. Getting sunburns during childhood increases the risk of cancer later in life.1 So get your kids into the routine of applying sunscreen every morning (after they brush their teeth) before going to school or to camp, no matter how cloudy it is outside.

WHICH SPF TO USE?

Sun protection factor (SPF) choices range from SPF 8 all the way up to SPF 100+. According to the Food and Drug Administration (FDA), SPFs below 15 protect against sunburns, but they do not prevent damage that can cause skin cancer.38 On the other hand, very high SPFs are misleading since SPF 30 protects against 97% of UV rays, SPF 50 protects against 98%, and SPF 100 protects against 99%. Sunscreens with the highest SPFs cost more and provide little additional protection, and they also encourage people to stay out in the sun longer and reapply less frequently. For effective sun protection, look for an SPF between 15 and 50.

In addition, make sure to choose “broad-spectrum” sunscreen, which guards against both UVB and UVA rays. While only 10% of UV radiation from the sun is UVB, this type of radiation is the primary cause of sunburns, wrinkling, and skin cancer.1 UVA rays penetrate deep into the skin to cause premature aging, and with enough exposure can also damage DNA to cause cancer.

You may be surprised to learn that the FDA does not check the ingredients in sunscreens to test if they are safe and effective. Many of the active ingredients in sunscreens have been used for so long that they are generally believed to be safe and effective, but that is different from being proven to actually be safe and effective. The FDA is currently working on a plan to start testing sunscreen ingredients for safety and effectiveness.

Consumer Reports rated the effectiveness of sunscreens but not their safety.  This is the list of the top sunscreen lotions and sticks from their 2016 report.  However, all of them are made with endocrine disrupting chemicals.  The sunscreens that are made with the safer ingredients (zinc oxide and titanium dioxide) scored very poorly in the Consumer Reports report.

Lotions

1. La Roche-Posay Anthelios 60 Melt-in Sunscreen Milk (note that this is much more expensive than other sunscreens listed)

2. Pure sun Defense Disney Frozen SPF 50

3. Coppertone Water Babies SPF 50

4. Equate (Walmart) Ultra Protection SPF 50

5. Ocean Potion Protect & Nourish SPF 30

6. Aveeno Protect + Hydrate SPF 30

Sticks

1. Coppertone kids stick SPF 55

2. Up & Up (Target) Kids stick SPF 55

LOTION OR SPRAY? WATERPROOF OR WATER-RESISTANT?

Avoid powder makeup and instead use liquid makeup products that contain SPF. Loose powders contain zinc and titanium that can be carcinogenic if inhaled.39 For this reason, the FDA no longer allows the manufacture of powder make-up with SPF, but some of these products are still on the market.

In addition, be sure to avoid sunscreen sprays, especially for kids. Sprays make it easy to inhale the chemicals that are found in the sunscreens. This can pose a safety issue, especially for small children who tend to squirm a lot while sunscreen is put on them. The FDA has also expressed concern about sprays but has not yet limited their use.8 Sunscreen lotion provides better protection against burns that cause skin cancer and aging, without the risk of inhaling dangerous chemicals. If a spray sunscreen is the only available option, first spray it in your hands before applying it to children. Do the same before applying it to the face of adults.

Waterproof sunscreens are no longer for sale. The FDA issued new guidelines that sunscreens can only be labeled as “water resistant” and must say whether they protect for 40 or 80 minutes while sweating or swimming.7 So be sure to reapply your water resistant sunscreen right after getting out of the water.

WHICH INGREDIENTS TO AVOID?

Even when sunscreens are approved by the FDA it does not mean that all the chemicals in them are entirely safe. Try to stay away from Vitamin A and oxybenzone. Vitamin A is found in about 25% of sunscreens because manufacturers claim that it prevents skin aging.40 However, the National Institutes of Health (NIH) has shown that the combination of sunlight and Vitamin A on the skin can increase your risk of cancer.41 The Environmental Working Group (EWG) recommends avoiding oxybenzone, which can potentially cause allergic reactions and interfere with hormones.42

THE BOTTOM LINE

So what should you do to prevent sunburns, aging, and skin cancer? Apply a generous amount of SPF 15 – 50 sunscreen lotion every morning, wear a hat and sunglasses, and generally try to stay in the shade. Reapply your sunscreen after extended sun exposure, sweating, and swimming. Always check the expiration date on sunscreens before you buy and use them, and stay away from tanning beds and sun lamps. If you are fair-skinned or have a family history of skin cancer, be extra careful.

Every year, the Environmental Working Group researches sunscreens on the market and rates them for safety and how well they work. To see how your sunscreen compares, visit their website. If your sunscreen is poorly rated, you can browse their site to find good alternatives.

Are Bisphenol A (BPA) plastic products safe for infants and children?

Environmental Exposures, Prevention
By Diana Zuckerman, PhD, Paul Brown, Laura Walls, and Anna E. Mazzucco, PhD

Bisphenol A (BPA) is a chemical used to make plastics. It is widely used in sports equipment, water bottles, medical devices, and as a coating in food and beverage cans. The Centers for Disease Control and Prevention found measurable amounts of BPA in the bodies of more than 90 percent of the U.S. population studied.43 The highest estimated daily intakes of BPA occur in infants and children.44

BPA is more likely to leach out of plastic when its temperature is increased, as when one warms up food in the microwave or warms up a baby bottle.2  In 2012, the Food and Drug Administration (FDA) banned the use of BPA in baby bottles—after several large manufacturers had already voluntarily removed it. Before the ban, most plastic baby bottles contained BPA.

How BPA affects our bodies

BPA mimics and interferes with the action of estrogen–a hormone that helps us develop when we’re young and eventually reproduce.45   BPA has been widely detected in blood, urine, amniotic fluid and breast milk, and has been found in nearly all adults and children who have been tested 46  For that reason, scientists are concerned about BPA’s  effects on fetuses, infants, and children at current exposure levels, and whether it can affect the prostate, brain, testicles, breasts, and behavior.2   Studies suggest that the more a baby is exposed to estrogen while in the womb, the greater the risk of breast, testicular and prostate cancer later in life.47,48,49

BPA’s effects on Animals and Human Cells

A study published in October 2008 also found that cancer cells exposed to low levels of BPA were more resistant to chemotherapy.50  Studies have also linked the hormonal effects of BPA from canned cat food to the epidemic of hyperthyroidism in cats, especially females.51 After studies of rats and mice linked BPA to hyperactivity and brain activity, the first study of nonhuman primates found that BPA levels were associated with cognitive problems that could affect learning and memory.52  BPA experiments on rats linked the chemical to precancerous lesions in the prostate and mammary glands, and to early puberty in females at BPA dosages similar to human exposures, according to a 2008 report on BPA by the National Institutes of Health’s National Toxicology Program.2 A 2014 study that  used mice to model prostate cancer in humans showed that a baby’s BPA exposure in the womb may increase risk of prostate cancer later in life 53  Another similar study in mice is creating concern about liver cancer risks as well.54  While early concerns were based primarily on animal studies and research on cells, there is increasing evidence from human studies that BPA causes serious harm. For instance, researchers have discovered possible links between BPA exposure and insulin resistance (a risk factor for Type II diabetes), increased formation and growth of fat cells (which can lead to obesity), and reproductive health problems for both men and women.4

The evidence so far is based on links scientists have observed between high levels in the body and health problems. Studies in which some people are intentionally exposed to BPA and others aren’t (randomized, controlled trials) have never been done because it could be dangerous and therefore is unethical.

Health Effects in Girls and Women

There is concern about the impact of BPA on early puberty in girls. Studies have also linked BPA to frequent miscarriages.4

In addition, several studies have found a connection between high levels of BPA and decreased fertility in women, including less success with in vitro fertilization treatments.55

Health Effects in Boys and Men

A 2009 research article reported that men who were exposed to very high levels of BPA at work had less sexual desire and were four times as likely to have problems getting and maintaining an erection than men who did not work with BPA.56 BPA-exposed workers were also seven times as likely to have problems with ejaculation. Although the men in this study had much higher levels of BPA exposure than the average man, this study demonstrates that BPA can harm men’s sexual health and that workers need to be protected. Research is needed to study the effects of more typical BPA exposures on men’s sexual health.  Unfortunately, several other studies have also linked high BPA levels to poorer sperm quality in men as well.57

Earlier Responses to BPA Concerns

The National Toxicology Program 2008 report recommended that more studies be conducted on BPA’s health effects on humans, and the report stated: “The possibility that bisphenol A may alter human development cannot be dismissed.”2

Also in 2008, based primarily on two chemical industry-funded studies, the Food and Drug Administration (FDA) claimed that BPA is safe.3 However, according to a publication of the American Chemical Society, the national professional association for chemists, 153 government-funded BPA experiments on lab animals and tissues found adverse effects while only 14 did not.1

After the 2008 National Toxicology report and FDA report, new studies of humans added greatly to concerns about the health risks of BPA.

In the fall of 2008, a major study was published in the Journal of the American Medical Association indicating that adults with higher levels of BPA in their bodies were more likely to be diagnosed with diabetes or heart disease.58 Adults with higher BPA were also more likely to be obese, but diabetes and heart disease were correlated with BPA levels even when obesity was statistically controlled.

Is it possible that BPA is contributing to the obesity epidemic and diabetes epidemic among children and adults? Wouldn’t it be ironic if the most popular water bottles for athletes contributed to obesity and diabetes?

Even before these more recent studies, the FDA Science Board, which consists of independent scientists who do not work for the FDA, disagreed with the FDA’s safety claims. The Science Board recommended in October 2008 that the FDA analyze the research literature again, relying less on the two industry-funded studies and taking into account the best independent studies. It also recommended that new research be conducted to examine BPA safety concerns. Government funding for that research was announced in late 2009.

What has actually been done to limit the potentially harmful effects of BPA?

In July 2013, the FDA responded to a petition from Representative Markey and comments from consumer groups by banning the use of BPA in packaging for infant formula, following on their 2012 ban of BPA from baby bottles.  But further action from FDA to eliminate BPA from cans and other food containers still has not happened.  Prior to the FDA ban, bills had been introduced in several states, cities, and in the U.S. Senate and House of Representatives (S. 593/H.R. 1523) to ban BPA in children’s products. Suffolk County in New York became the first in the U.S. to ban BPA in baby bottles and sippy cups, in March, 2009.   In March 2009, the six major manufacturers of baby bottles in the United States announced that they would no longer sell baby bottles made with BPA in the U.S.59 A few days later, SUNOCO, a BPA manufacturer, announced that it would require customers to confirm that no BPA would be used in food or water containers for children under 3 years of age.60  In 2008, manufacturers such as Playtex and Nalgene and retailers such as Wal-Mart pledged to remove BPA from their products and stores by the end of the year.61

Despite these efforts, BPA still remains in many canned food and beverages sold to people and pets in the U.S. and other countries.  But at least two producers of canned foods in the U.S. have BPA-free cans: Eden Foods began using BPA-free cans in 1999 and now uses BFA-free cans for everything except highly acidic tomato products, and Vital Choice introduced new cans and pouches for its fish products at the end of 2008.62,63  According to Eden, it costs the company $300,000 more a year to produce BPA-free cans, which are 14% more expensive than industry standard cans; this translates into about 2 cents more per can.64  In 2012, Campbell’s also announced that it would phase out BPA from its canned foods, although this has not yet happened.

What you can do to lower your family’s exposure to BPA

While we wait for more research to be conducted, you may want to avoid BPA. Is that possible? A 2011 study from the Silent Spring Institute showed that you can lower your BPA levels significantly by avoiding pre-packaged food and keeping your food from coming into contact with plastic containers, plastic utensils, and non-stick pans during preparation, eating and storage.65

BPA is found in polycarbonate (PC) plastics, which are typically clear and hard, marked with the recycle symbol “7″ or may contain the letters “PC” near the recycle symbol.

To avoid warming up food in plastic containers with these or other chemicals, use stoneware, china, or glass dishes and containers in your microwave. In 2012, the FDA banned BPA in baby bottles and children’s drinking cups, after several large manufacturers had already voluntarily removed it. However, bottles from before 2012 may still contain BPA.  Another problem is that manufacturers are replacing BPA in plastic bottles with other chemicals that experts believe have many of the same effects as BPA but that we know even less about. For that reason, parents may want to include safer alternatives such as glass baby bottles, particularly for use at home.

Can wearing a bra cause breast cancer?

Breast Cancer, Prevention
Caroline Novas

There are several persistent email and internet rumors about potential causes of breast cancer. One is that wearing a bra, or wearing an underwire bra, causes the disease.

The idea that bras may cause cancer was fueled by the 1995 book called Dressed to Kill by Sydney Ross Singer and Soma Grismaijer. It claims that women who wear underwire bras for 12 hours a day have a much higher risk of developing breast cancer than women who do not wear bras.They maintain that bras restrict the lymph system, which results in a build-up of toxins in the breasts.66 However, according to the American Cancer Society, there is no evidence that compression of the lymph nodes by bras causes breast cancer; in reality, body fluids travel up and into the underarm lymph nodes, not towards the underwire.67 Similarly, there is no sufficient evidence that any types of bras cause breast cancer.

In Dr. Susan Love’s Breast Book, Love claims that the hypothesis about bras causing cancer stems from our desire to have control over areas of life where we have a lot of uncertainty or fear. People want something to blame, and also hope that by avoiding bras they can avoid breast cancer.68 While there are geographic variations in breast cancer rates, there are many, many factors, including diet, exercise, lifestyle, childbearing practices, as well as other behaviors and exposures that are more plausible explanations for these regional differences in breast cancer than bras. In places where people have less access to medical care, breast cancer will not be diagnosed as often, even though it might be present. And because the risk of breast cancer increases as women get older, breast cancer rates will be lower in parts of the world where people die of other causes at younger ages, whether they have worn bras or not.

Even if women who wear underwire bras are more likely to be diagnosed with breast cancer, a likely explanation would be that many women with larger breasts also tend to be heavier. Being overweight or having a lot of body fat puts a woman at increased risk for breast cancer.69 It would make sense that women with larger breasts are both more likely to wear underwire bras and more likely to develop breast cancer. But this doesn’t mean that underwire bras cause breast cancer!

In a study published in 2014, researchers interviewed postmenopausal female participants about their lifetime bra wearing patterns. Evaluating more than 1,000 women with breast cancer and almost 500 who did not have breast cancer, the researchers found no evidence of a connection between the number of hours spent wearing a bra or wearing an underwire bra and increased breast cancer risk.70

The bottom line: well-designed studies have not convinced experts that wearing bras or underwire bras increase your chances of developing breast cancer. Here are some factors that are associated with increased risk of breast cancer:71

Risk factors you can’t control

  • Sex: Women represent 99% of all breast cancer patients and have a 12.1% chance of being diagnosed with breast cancer during their lifetime.
  • Age: The chances of getting breast cancer increase with age. About 65% of women are over 55 years old when they are diagnosed.
  • Race: After age 45, white women are more likely to get breast cancer than black women, but black women have a higher incidence before age 45 and are more likely to die from breast cancer.
  • Family history: Certain inherited gene mutations (BRCA1 and BRCA2) increase the risk of developing breast cancer. However, these genes account for only 5-10% of overall cases. Even without those genes, having a grandmother, mother, sister, or daughter diagnosed with breast or ovarian cancer increases the risk.
  • A previous history of breast cancer, abnormal breast cells (atypical hyperplasia) or certain non-invasive “pre-cancers” like lobular carcinoma in situ (LCIS) or ductal carcinoma in situ (DCIS) increase the risk of developing invasive cancer.
  • Beginning menstruation early (before age 12) increases the risk of breast cancer by affecting the level of reproductive hormones a woman is exposed to during her lifetime.
  • Starting menopause late (after age 55) increases the risk of breast cancer.
  • Dense breast tissue (including fibrocystic breasts) increases the risk of breast cancer

Risk factors you can (possibly) control

  • Women who delay having their first child until later in life or who never have children are at a higher risk for breast cancer.In contrast, having children at a younger age and breastfeeding decrease the risk of developing breast cancer
  • Women who take hormonal therapy for menopause are at an increased risk for breast cancer.
  • Being overweight or obese increases the risk of postmenopausal breast cancer
  • Physical inactivity increases risk.
  • Women who drink an average of 2 alcoholic beverages per day increase their breast cancer risk by 21%. The more a woman drinks, the greater her risk.
  • High levels of radiation in the chest area before the age of 30 increase the risk.
  • Women who took DES during pregnancy (this drug was mainly used in the 40s, 50s, 60s, and 70s) are at an increased risk of breast cancer. The risk to their daughters is still being studied.
  • There is growing evidence that smoking and exposure to tobacco smoke probably increase breast cancer risk.
  • The use of oral contraceptives may slightly increase the risk of developing breast cancer. Some studies have found no increased risk from taking birth control pills and others have shown an increased risk.

If you are worried about your risk of breast cancer, you should discuss your concerns with a health care professional and find out about ways to cut your risk. Knowing the real risk factors and making healthy lifestyle choices can help you reduce your risks. Going braless won’t.

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