Ask the Dietitian: How Does Diet Affect Cancer Risk?

Q: How does eating a plant-based diet affect my cancer risk?

Ginny Messina, R.D.: When you replace animal foods in your diet with plant foods, there is a very good chance that you’ll reduce your risk for cancer. The most comprehensive report on diet and cancer is from the American Institute for Cancer Research and the World Cancer Research Fund. The report specifically talks about the importance of a plant-based diet for reducing cancer risk.

Two types of compounds that appear to be protective against cancer are fiber and phytochemicals. Both are found only in plant foods. There are many ways in which these and other plant compounds lower cancer risk. For example, antioxidants in plants can prevent the oxidation that leads to mutations. Phytochemicals in berries may interfere with growth of blood vessels that feed tumors. Compounds in cruciferous vegetables (the ones in the cabbage family like broccoli, cauliflower and collard greens) induce death of cancer cells. Beans are rich in resistant starch, a type of starch that isn’t well digested and that may protect against colon cancer when bacteria break it down in your digestive tract. Plant estrogens in soyfoods can inhibit the growth of cancer cells. Even coffee and olive oil provide compounds that may fight cancer.

The research on diet and cancer is still evolving and it’s a difficult relationship to study. So we still have lots of questions about how best to reduce risk. And there is no evidence that a plant-based diet can cure cancer. But clearly, a diet based on a wide variety of plant foods will provide all types of cancer-fighting compounds. Rather than focus on any one food, it’s good to simply eat a variety of healthful plant foods.

More cancer info:

Vegan Diets to Reduce Colon Cancer Risk

Preventing Prostate Cancer with Diet


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