Category Archives: Pancreatic Cancer

Boosting Healthy Bacteria for a Healthy Pancreas

Jessica Cote and Danielle Shapiro, MD, MPH, Cancer Prevention and Treatment Fund

Pancreatic cancer is rare–less than 2% of Americans will develop it in their lifetimes. However, pancreatic cancer is the 4th most common cause of cancer-related deaths in the U.S. claiming more than 43,000 American lives in 2017.1  The good news is that  prevention is possible, since most pancreatic cancers are not cause by inherited genes. Smoking and alcohol use are the major known causes, and can double the lifetime risk to about 3%.2 Quitting smoking and cutting back on alcohol are good ways to prevent pancreatic cancer and so is a healthy mouth and gut. Scientists have recently discovered that the bacteria living in our bodies can help us stay healthy and ward off dangerous cancers.

What is the Microbiome?

Inside our bodies we have hundreds of type of living bacteria and other organisms; this community of microorganisms is called the microbiome. These organisms live in harmony with our body and can keep us from getting sick, so we call them “probiotic” or “good bacteria.” In 2012, Scientists from the National Institutes of Health started the Human Microbiome Project to study the role of the microbiome in human health and disease.

We can increase the amounts of good bacteria in our body by eating foods rich in natural probiotics or taking a probiotic supplement. Probiotic-rich foods include: yogurt, sourdough bread, sour pickles, soft cheeses, sauerkraut, tempeh (fermented soy and grains), and other foods. Check out this list — you’re bound to find something you like!

Oral Bacteria and Pancreatic Cancer

A 2017 review found that gum disease can increase the chances of developing pancreatic cancer in a lifetime to about 2.4% to 3.2%. When scientists studied the blood of patients before they got diagnosed with pancreatic cancer, they began to find patterns of “bad” vs. “good” bacteria.3

Since diagnosing cancer early is the key to effective treatment, scientists hope that it will soon be possible to have a simple screening test for pancreatic cancer by testing the saliva for certain bacteria. They believe that 9 times out of 10, if certain bacteria are present, the person is not likely to have pancreatic cancer.4

Although medical experts aren’t completely certain how to remove bad bacteria from the mouth and gums, they usually recommend flossing and brushing teeth regularly as well as rinsing with mouthwash as the best ways to get rid of them.

Gut Bacteria and Pancreatic Cancer

Like the mouth, certain bacteria in the gastrointestinal (GI) tract may have a role to play in the development of pancreatic cancer. The bacteria Helicobacter pylori, which causes stomach ulcers and stomach cancer, can increase the lifetime risk of pancreatic cancer to about 2.4%. These trends were more frequently seen in people living in Europe and East Asia rather than North America, which suggests that environment, diet (red meat or high temperature foods), and genetics may all help to increase or decrease the chances of developing pancreatic cancer.5

The Bottom Line

More research is needed to understand the link between bacteria and pancreatic cancer, and medical experts have not yet figured out how best to reduce the number of harmful bacteria in our bodies and increase the good kind. Until then, take good care of your mouth (brushing and flossing and regular visits to your dentist) and keep your gut healthy by eating fruits, vegetables, and foods rich in natural probiotics such as yogurt. See memphis article to know more.


  1. National Cancer Institute. Cancer Stat Facts: Pancreas Cancer. Accessed Dec. 18, 2017. Available online:
  2. National Cancer Institute. Pancreatic Cancer Treatment (PDQ®)–Patient Version. (Dec. 23, 2016). Available online:
  3. Bracci PM. Oral Health and the Oral Microbiome in Pancreatic Cancer: An Overview of Epidemiological Studies.The Cancer Journal. 2017;23(6): 310–314. doi: 10.1097/PPO.0000000000000287
  4. Ertz-Archambault N, Keim P, Von Hoff D. Microbiome and pancreatic cancer: A comprehensive topic review of literature. World Journal of Gastroenterology. 2017;23(10):1899-1908. doi:10.3748/wjg.v23.i10.1899.
  5. Xiao M, Wang Y, Gao Y. Association between Helicobacter pylori Infection and Pancreatic Cancer Development: A Meta-Analysis. Miao X, ed. PLoS ONE. 2013;8(9):e75559. doi:10.1371/journal.pone.0075559.

Alcohol and Cancer

Ealena Callender, MD, MPH, & Meg Seymour, PhD, Cancer Prevention and Treatment Fund

The link between alcohol and cancer may surprise you. The American Society of Clinical Oncology reports that drinking alcohol increases the risk of cancer of the mouth and throat, vocal cords, esophagus, liver, breast, and colon. The risks are greatest in those with heavy and long-term alcohol use. Even so, moderate drinking can add up over a lifetime, which could be harmful.1

What is Moderate Drinking? Heavy Drinking?

The 2020-2025 Dietary Guidelines for Americans recommends that Americans can reduce their risk of alcohol-related health problems by drinking in moderation, which means 1 drink per day or less for women and 2 drinks per day or less for men.2 However, not all “drinks” are equal. A drink is defined as approximately 0.6 fluid ounces of alcohol, which equals: 1.5 ounces of distilled spirits (e.g., vodka, gin, tequila, etc), 5 ounces of wine, 12 ounces of beer, and 8 ounces of malt liquor.3 (Click here to see the CDC’s fact sheet.) The guidelines define moderate drinking as two drinks or less per day for men and one drink or less per day for women.

The CDC describes heavy drinking as having more than eight drinks per week for women and more than 15 drinks per week for men. Binge drinking refers to consuming multiple drinks on a single occasion – four or more drinks for women and five or more drinks for men.

Drinking and Cancer

In January 2023, the Canadian Centre on Substance Use and Addiction (CCSA) published updated guidelines that recommend limiting alcohol use to two or fewer drinks per week to reduce the risk of harm from alcohol.4 At that level, they say risk of harm from alcohol is low. Risk is moderate for those who drink three to six servings of alcohol per week and “increasingly high” for those who drink seven or more. The report warns that drinking three to six alcoholic beverages per week is associated with increased risk of several types of cancer.

These guidelines may surprise many people, especially those who assumed moderate drinking was not anything to be concerned about.  But research indicating the risk of cancer from drinking even small amounts of alcohol has been published for years.  For example, Alcohol is known to cause at least six types of cancer: mouth and throat cancer, larynx (voice box) cancer, esophageal cancer, colon and rectal cancer, liver cancer, and breast cancer in women.5 A 2021 study found that 4% of all new cancer cases diagnosed throughout the world in 2020 were attributable to alcohol consumption, and the researchers say that may be a low estimate.6

Depending on the amount a person drinks, they can increase their chances for developing even rare cancers. For example, moderate drinkers can almost double their lifetime risk of mouth and throat cancer to almost 2%, while heavy drinkers increase their risk of having mouth or throat cancer, from 1% to 5%.1 A 2020 study from Australia found that the heaviest drinkers (drinking more than 14 drinks per week) had an overall higher likelihood of developing cancer, compared with those who drank the least (1 or 0 drinks per week). The men who drank the most had a 4.4% higher overall likelihood of developing cancer than the men who drank the least, and the women who drank the most had a 5.4% higher overall chance of developing cancer.7

Women need to be more cautious about drinking any amount of alcohol because the alcohol is even more likely to cause cancer in women than in men. Research has shown that women who drink even 1 drink per day have a 5-9% higher chance of developing breast cancer, compared with women who do not drink.8 The risk is even higher for women who drink more. One reason may be that alcohol affects the amounts of certain sex hormones circulating in the body. For women who have had hormone receptor-positive breast cancer, seven or more weekly drinks increased the chances of having a new cancer diagnosed in the other breast from about 5% to about 10%.1

Heavy drinking is also risky for those who currently have or have had other types of cancer. Among all cancer survivors, heavy drinking caused an 8% increased risk in dying and a 17% increased risk of cancer recurrence. Patients with cancer who abuse alcohol do worse because alcohol causes poorer nutrition, a suppressed immune system, and a weaker heart.1

In 2020, an estimated 100,000 cases of cancer globally were caused by light to moderate drinking (fewer than two alcoholic beverages per day).6 A study of alcohol use in the European Union found that a drinking level of less than one drink per day was linked to 40% of alcohol-related cancers in women and 32% in men.9

Individuals who increase their alcohol use may also increase their chance of getting cancer, according to a large 2022 study.10 Compared with men and women who maintained the same level of drinking over about six years, the study found that those who increased their alcohol consumption were more likely to get cancer. While those who increased their alcohol consumption most dramatically saw a more significant increase in their risk of cancer, even those who only increased their consumption by a small amount had a higher risk of cancer than those who did not change their level of drinking.

How Alcohol Causes Cancer

Scientists believe that alcohol causes cancer in several ways:1

  • Alcohol (ethanol) is broken down into a toxic substance called acetaldehyde, which is directly toxic to the body’s cells.
  • Alcohol causes damage to cells through a process called free-radical oxidation.
  • Alcohol causes the body to absorb less folate (an important B vitamin) and other nutrients (antioxidant vitamins A, C, and E), which naturally repair damage and fight off cancers.
  • Alcohol increases the body’s level of estrogen (a sex hormone associated with breast cancer)

What You Can Do to Lower Cancer Risk for You and Your Family

  • If you drink alcohol, limit drinks to an average of 1 a day for women and 2 a day for men.
  • Recognize heavy drinking in a loved one,because the more a person drinks, the greater his or her chances of developing cancer. The “CAGE” questionnaire provided here can help spot heavy drinking.
    1.   Has the person tried to Cut back?
    2.   Has the person been Annoyed when asked about drinking?
    3.   Has the person felt bad or Guilty?
    4.   Has the person needed a drink first thing in the morning (Eye opener)? Each “yes” counts as 1 point. A score of 2 or more suggests problem drinking.
  • Talk with your doctor about your risk.Doctors can refer or offer counseling and treatment services to patients with risky drinking habits.
  • Seek help early. Problem drinking can’t be wished away. There are many resources to access information and help. The Substance Abuse and Mental Health Services Administration (SAMHSA), which is part of the U.S. Department of Health and Human Services (HHS) has a toll free hot-line and website. Call 1-800-662-HELP (4357) or visit
  • Practice healthy habits. Eating a diet rich in cancer-fighting nutrients (i.e., fruits and vegetables), exercising, maintaining a healthy weight, reducing stress, and getting restful sleep can all help to lower cancer risk. Don’t smoke, and quit if you do. Drinking and smoking increases cancer risk more than either one alone.

The Bottom Line

To decrease your chances of cancer and other serious health problems, try to limit your drinking.  If you drink alcohol, try to drink less often and aim for a maximum average of 1 a day if you’re a woman and 2 a day if you’re a man.

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

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



1. LoConte NK, Brewster AM, Kaur JS, Merrill JK, Alberg AJ. Alcohol and cancer: a statement of the American Society of Clinical Oncology. Journal of Clinical Oncology. 2018;36(1):83-93.

2. U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020-2025. 9th Edition. December 2020. Available at

3. Centers for Disease Control and Prevention. Dietary Guidelines for Alcohol. Updated December 2020.


5. Centers for Disease Control and Prevention. Alcohol and Cancer. Updated July 2019.

6. Rumgay H, Shield K, Charvat H, Ferrari P, Sornpaisarn B, Obot I, Islami F, Lemmens VE, Rehm J, Soerjomataram I. Global burden of cancer in 2020 attributable to alcohol consumption: A population-based study. The Lancet Oncology. 2021;22(8):1071-80.

7. Sarich P, Canfell K, Egger S, Banks E, Joshy G, Grogan P, Weber MF. Alcohol consumption, drinking patterns and cancer incidence in an Australian cohort of 226,162 participants aged 45 years and over. British Journal of Cancer. 2021;124(2):513-23.

8. National Institute on Alcohol Abuse and Alcoholism. Women and Alcohol. Updated April 2021.

9. Rovira, P., & Rehm, J. (2021). Estimation of cancers caused by light to moderate alcohol consumption in the European Union. European journal of public health31(3), 591–596.

10. Yoo, J. E., Han, K., Shin, D. W., Kim, D., Kim, B. S., Chun, S., Jeon, K. H., Jung, W., Park, J., Park, J. H., Choi, K. S., & Kim, J. S. (2022). Association Between Changes in Alcohol Consumption and Cancer Risk. JAMA network open5(8), e2228544.


Pancreatic cancer: are you at risk?

Heidi Mallis, Cancer Prevention & Treatment Fund

Pancreatic cancer is the 3rd leading cause of cancer death among women and men in the U.S.[1]

Surprising Facts

  • The five-year survival rate is less than 8%. This figure has improved only slightly since 1975, when it was 3%.[2]
  • There is no reliable screening test for early detection of pancreatic cancer.[3]
  • Only about 2.5% of the National Cancer Institute’s federal research funding is currently allocated to pancreatic cancer.[4]
  • Pancreatic cancer has claimed the lives of several public figures including: actors Patrick Swayze and Alan Rickman, opera tenor Lucianno Pavarotti, and professor and bestselling author Dr. Randy Pausch.[5]

Risk Factors

Every year, more than 50,000 people are diagnosed with pancreatic cancer in the U.S., and more than 40,000 people die from the disease.[6] It is known as a “silent killer” because its symptoms (pain, jaundice, and weight loss) can easily be mistaken for other diseases. Diagnosis is often at an advanced stage when the cancer has spread to other parts of the body, making treatment more difficult. That is why new research is needed to help identify earlier warning signs that could lower the fatality rate for this disease.

Several risk factors are known. Most are common and can’t be changed. The following traits increase your risk of developing pancreatic cancer:

  • 60 years of age or older
  • African American
  • Male
  • Smoking:  Smokers are 2-3 times more likely to develop pancreatic cancer than nonsmokers, and smoking is responsible for 20-30% of all pancreatic cancer cases.
  • Type 2 diabetes:  Several studies show that people with diabetes are more likely to also develop pancreatic cancer and vice versa, but it is unclear whether diabetes causes pancreatic cancer or is caused by pancreatic cancer.[7][8]
  • Family history of pancreatitis (inflammation of the pancreas), ovarian, or colon cancer. If a person has an immediate family member who has any of these types of cancer, his or her chance of developing pancreatic cancer is tripled.[9]

Research has shown that family history or shared genes were a risk factor for pancreatic cancer. In 2009, new light was shed on the role of genes when a study showed that people with blood type O may have a lower risk of pancreatic cancer than those with blood types A, B, or AB. The study was conducted by a group of researchers from several academic institutions that are part of the Pancreatic Cancer Cohort Consortium, which is affiliated with the National Cancer Institute (NCI).[10] The group hopes to further examine genetic risks, and future findings could help increase early detection and prevention of pancreatic cancer.

Regardless of blood type and other risk factors, individuals can reduce their risk of developing pancreatic cancer by lowering controllable risk factors. A study revealed that a diet rich in fresh fruit and vegetables, Vitamin C, and fiber might actually reduce the risk of developing pancreatic cancer.[11] Other risk factors, such as smoking or diabetes related to weight gain, can be reduced by quitting smoking and maintaining a healthy weight, which decreases a person’s risk of many other diseases as well. In addition, one study of 60,000 adults indicates that drinking fewer (non-diet) soft drinks may decrease the risk of pancreatic cancer.[12] The authors suggest that sugary drinks, by increasing insulin levels, help fuel pancreatic cancer cell growth. They also speculate that people who consume more soft drinks tend to be more likely to smoke and to eat red meat, all of which are considered potential risk factors for pancreatic cancer.

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


  1. Cancer Treatment Centers of America. (2016, October). What should you know about pancreatic cancer?
  2. National Cancer Institute. (2016, April). Cancer Stat Facts: Pancreas Cancer.
  3. American Cancer Society (2017). Can cancer of the pancreas be found early?
  4. Office of Budget and Finance. Fiscal year 2015 fact book. National Cancer Institute.
  5. Pancreatic Cancer Action Network (2016). Public figures affected by pancreatic cancer.
  6. American Cancer Society (2017). Key statistics for pancreatic cancer.
  7. Coughlin SS, Calle EE, Teras LR, Petrelli J, Thun MJ (2004). Diabetes mellitus as a predictor of cancer mortality in a large cohort of US adults. American Journal of Epidemiology, 159: 1160-1167.
  8. European Cancer Organisation. (2017, January). Diabetes or its rapid deterioration can be an early warning sign for pancreatic cancer.
  9. National Cancer Institute (2017). Pancreatic cancer. U.S. National Institutes of Health.
  10. Amundadottir L, Kraft P, Stolzenberg-Solomon RZ, et al (2009, August 2). Genome-wide association study identifies variants in the ABO locus associated with susceptibility to pancreatic cancer. Nature Genetics, September 2009; 41(9): 986-990.
  11. Ghadirian P, Lynch HT, and Krewski D (2003). Epidemiology of pancreatic cancer: an overview. Cancer Detection and Prevention, 27(2): 87-93.
  12. Muelle NT, Odegaard A, Anderson A, Yuan J-M, Koh W-P, Pereira MA. Soft Drink and Juice Consumption and Risk of Pancreatic Cancer: The Singapore Chinese Health Study. Cancer Epidemiology, Biomarkers & Prevention. 2010.19(2);447-455.


Can a handful of nuts a day keep cancer away?

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.
  17. Freitas R.D.S., Campos M.M.. Protective effects of omega-3 fatty acids in cancer-related complications. (2019). Nutrients;11(5):945.,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.