Among more than 1,700 men with and without prostate cancer, those who ate the most fiber — particularly from vegetable sources — had a lower risk of developing the disease, Italian researchers found. The benefit was “moderate,” they report in the International Journal of Cancer, but the findings suggest that at least some forms of fiber offer prostate cancer protection.
A number of studies have suggested that eating plenty of fruits and vegetables may help ward off prostate cancer, while “Western”-style diets heavy in animal fat and dairy products may increase a man’s risk of the disease. But not all studies have reached these conclusions, and the importance of diet in prostate cancer risk is still unclear.
There is evidence that fiber-rich foods may lower the risk of heart disease, diabetes and possibly certain cancers. However, studies looking at fiber and prostate cancer have generally yielded “null” findings, said Dr. Claudio Pelucchi, a researcher at the Mario Negri Institute for Pharmacological Research in Milan and lead author of the new study.
The difference in his team’s study, Pelucchi told Reuters Health, is that it broke down men’s fiber intake according to the type and source of fiber.
Fiber comes in two main forms, soluble and insoluble. Soluble fiber partially dissolves in water, and its food sources include vegetables, fruit, oatmeal and legumes. Insoluble fiber, which passes through the digestive system largely intact, is found in foods like whole grains, seeds and the skin on fruit.