Prevention and Lifestyle Factors

Click the icon to see an image of prostate cancer.

• Polyphenols, found in apples, onions, and green tea, may be beneficial, although this is controversial. (Chemicals in green tea in particular have been studied for cancer-fighting effects in breast cancer.)
• Lycopene, found in tomatoes may have cancer-fighting properties.

Click the icon to see an image of phytochemicals.

• There is some evidence that foods containing folate (folic acid) may be protective. It is found in avocado, bananas, orange juice, asparagus, fruits, green leafy vegetables, dried beans and peas, and yeast. It is also added to commercial grain products.

Click the icon to see an image of folate sources.

• Low levels of vitamin D may increase breast cancer risk, especially in older women. Vitamin D is activated by sunlight and obtained from fortified milk.

Click the icon to see an image of vitamin D sources.

• Foods high in vitamin C have also been associated with a lower risk (although there is not evidence of protection from any vitamin supplements, including C or E).

Click the icon to see an image of vitamin C sources.

Dairy Products and Other Protein Foods. Studies suggest that dairy products may also play a protective role in premenopausal women. If this is eventually verified, it is not clear if protection comes from calcium and vitamin D in these foods or if there are others factors involved. Women who increase their intake should choose low- or no-fat dairy products.

One study reported that women with breast cancer who had a high intake of protein from both poultry and dairy products had a better outlook than those with a lower intake of these foods. In this study, red meat appeared to have no effect one way or the other. Other studies, however, have found a higher risk of breast cancer in women who consume higher quantities of flame-broiled meats, particularly women who are sensitive to chemicals released during the process. Fish may offer some protection.

Iron. Animal studies have linked a higher incidence of breast cancer with iron-rich diets, and in humans, high iron stores have been associated with a higher risk for breast cancer. Estrogen appears to increase iron levels in cells, and iron produces oxidants (damaging particles) that are associated with cancer. More research is needed to confirm these findings, however.