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Nutrition in Cancer Care (PDQ®)

Patient Version
Last Modified: 12/28/2011

Nutrition in Cancer Prevention

Key Points for This Section


Following certain dietary guidelines may help prevent cancer.

The American Cancer Society and the American Institute for Cancer Research both have dietary guidelines that may help prevent cancer. Their guidelines are a lot alike and include the following:

  • Eat a plant-based diet, with at least 5 servings of fruit and vegetables a day. Have several servings a day of beans and grain products (such as cereals, breads, and pasta). Eat less meat.

  • Eat foods low in fat.

  • Eat foods low in salt.

  • Get to and stay at a healthy weight.

  • Be active for 30 minutes on most days of the week.

  • Drink few alcoholic drinks or don't drink at all.

  • Prepare and store food safely.

  • Do not use tobacco in any form.

The effect of soy on breast cancer and breast cancer prevention is being studied.

Study results include the following:

  • Some studies show that eating soy may decrease the risk of having breast cancer.
  • Taking soy supplements in the form of powders or pills has not been shown to prevent breast cancer.
  • Adding soy foods to the diet after being diagnosed with breast cancer has not been shown to keep the breast cancer from coming back.

Soy has substances in it that act like estrogen in the body. Studies were done to find out how soy affects breast cancer in patients who have tumors that need estrogen to grow. Some studies have shown that soy foods are safe for women with breast cancer when eaten in moderate amounts as part of a healthy diet.

If you are a breast cancer survivor be sure to check the most up-to-date information when deciding whether to include soy in your diet.



Glossary Terms

alcohol (AL-kuh-hol)
A chemical substance found in beer, wine, and liquor, and some medicines, mouthwashes, household products, and essential oils (scented liquid taken from plants). Alcohol contains a carbon atom attached to a hydroxyl group (a molecule made of an oxygen atom and a hydrogen atom).
breast cancer (brest KAN-ser)
Cancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare.
cancer (KAN-ser)
A term for diseases in which abnormal cells divide without control and can invade nearby tissues. Cancer cells can also spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is a cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is a cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is a cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord. Also called malignancy.
diagnosis (DY-ug-NOH-sis)
The process of identifying a disease, such as cancer, from its signs and symptoms.
diet (DY-et)
The things a person eats and drinks.
dietary supplement (DY-uh-TAYR-ee SUH-pleh-ment)
A product that is added to the diet. A dietary supplement is taken by mouth, and usually contains one or more dietary ingredient (such as vitamin, mineral, herb, amino acid, and enzyme). Also called nutritional supplement.
estrogen (ES-truh-jin)
A type of hormone made by the body that helps develop and maintain female sex characteristics and the growth of long bones. Estrogens can also be made in the laboratory. They may be used as a type of birth control and to treat symptoms of menopause, menstrual disorders, osteoporosis, and other conditions.
soy (soy)
A product from a plant of Asian origin that produces beans used in many food products. Soy contains isoflavones (estrogen-like substances) that are being studied for the prevention of cancer, hot flashes that occur with menopause, and osteoporosis (loss of bone density). Soy in the diet may lower cholesterol levels and reduce the risk of heart disease. Also called Glycine max, soya, and soybean.
survivor (ser-VY-ver)
One who remains alive and continues to function during and after overcoming a serious hardship or life-threatening disease. In cancer, a person is considered to be a survivor from the time of diagnosis until the end of life.
tobacco (tuh-BA-koh)
A plant with leaves that have high levels of the addictive chemical nicotine. The leaves may be smoked (in cigarettes, cigars, and pipes), applied to the gums (as dipping and chewing tobacco), or inhaled (as snuff). Tobacco leaves also contain many cancer-causing chemicals, and tobacco use and exposure to secondhand tobacco smoke have been linked to many types of cancer and other diseases. The scientific name is Nicotiana tabacum.
tumor (TOO-mer)
An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumors may be benign (not cancer), or malignant (cancer). Also called neoplasm.