Eating Grains May Lower Risk of Advanced Prostate Cancer
A new international study found that eating more fiber from grains may slightly reduce the risk of developing advanced prostate cancer and dying from it. However, fiber from fruit and vegetables did not show the same benefit.
Some foods, like oatmeal. quinoa, and wild rice are naturally whole grains. To ensure breads, cereals, flours, and pastas are whole grain, check the ingredients list for the word ¡°whole¡± before any type of grain, such as whole wheat flour, whole grain corn, and whole rye berries or flour. Don¡¯t rely on how darkly colored a food is to indicate how rich it is in whole grains or on front-of-the-package descriptions, like ¡°made with whole grain,¡± ¡°double fiber,¡± or ¡°multigrain,¡± because they don¡¯t guarantee that the food is 100% whole grain.? Credit: USDA Food and Nutrition Service
The Challenge
Prostate cancer found at an early stage, when tumors are slow-growing, small, and contained to the prostate gland, have an almost 100% 5-year survival. But prostate cancers found at a late (advanced) stage, when tumors have spread to other parts of the body, have a 30% to less than 40% 5-year survival rate.
Understanding which foods might help lower the risk of advanced or aggressive prostate cancer could save lives.
Some early research has shown that lycopene antioxidants in tomatoes and proteins called isoflavones in soybeans might help prevent or lower the risk of developing some prostate cancers.
Other studies have suggested that eating a lot of dairy products or other foods with a lot of calcium may increase the risk for developing prostate cancer.
The exact role of diet in prostate cancer isn¡¯t clear. Researchers continue to look for foods, or substances in foods that can help lower the risk for developing prostate cancer.?
Researchers hypothesize that dietary fiber may lower? the risk of prostate cancer because high amounts of dietary fiber have been linked with lower overall inflammation and improve insulin sensitivity.
The Research
A large group of researchers from 15 large cohort studies across the world, including two from the ÁñÁ«ÊÓƵ (ÁñÁ«ÊÓƵ)¡ªYing Wang, PhD, and recently retired Marjorie McCullough, ScD,¡ª analyzed data from over 842,000 men across North America, Europe, Australia, and Asia to learn whether dietary fiber affected the risk of developing advanced and aggressive forms of prostate cancer.
No men had prostate cancer when the study started, but during the follow-up time, about 52,700 men developed it during follow-up periods ranging from 9 to 22 years.
Each study asked participants to answer a food frequency questionnaire or to give diet histories to learn about their consumption of fiber during the previous year¡ªbefore they were diagnosed with cancer.?
The researchers looked at total dietary fiber and fiber specific food types: fruits, vegetables, and grains. They published their findings in the in July 2025.
Key findings:
- Total dietary fiber consumption was not associated with lower risk of prostate cancer overall.
- Fiber from fruits and vegetables showed no benefits in lowering the risk of developing an advanced stage of cancer or dying from cancer.
- Fiber from grains, however, was modestly linked to a lower risk of progression to advanced prostate cancer and death from prostate cancer.
Because grains contain many nutrients with ¡°anticarcinogenic properties,¡± including minerals and vitamins, the authors pointed out that the small protective effect from eating grains could be due to the nutrients in them rather than from the dietary fiber. However, after adjusting for whole-grain (defined as foods with more than 50% whole grain content) consumption, they found similar results.
Why It Matters
While no food can completely prevent cancer, this study adds to the growing evidence that choosing whole grains over refined grains (like white bread or pasta) may help protect against some serious diseases¡ªincluding advanced prostate cancer.
Future studies could add more detail to the current knowledge base by evaluating:
- Whether associations differ?by race or ethnicity¡ªmore than 90% of the men studied were White.
- How the frequency and timing of food questionnaires affect the results, as for these pooled studies, food questionnaires were only answered one time, at baseline before diagnosis.
- Whether association between grain consumption and prostate cancer is affected by screening PSA tests, acocunting for when and how often the test was?done¡ªthese pooled studies didn¡¯t account for PSA testing.
Simple Ways to Add More Grain Fiber
Eating more fiber from grains¡ªnot fruits or vegetables¡ªmay slightly lower your chances of developing advanced prostate cancer or dying from it. It¡¯s one more reason to choose whole grains as part of a balanced diet. Here¡¯s how to get started:
- Start your day with oatmeal or whole grain cereal
- Choose whole wheat bread instead of white
- Serve brown rice, barley, or quinoa as side dishes
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