Soy Intake and the Risk of Breast Cancer Agawam MA

Breast cancer is a 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. There are different types of breast cancer, with different stages (spread), aggressiveness and genetic makeup. Treatment includes surgery, drugs (hormone therapy and chemotherapy) and radiation. The incidence of breast cancer has been increasing steadily for decades. Today breast cancer rates have escalated to the point where women's lifetime risk of developing breast cancer is 1 in 8. In the year 2002, the American Cancer Society estimated that nearly 203,500 women will be diagnosed with breast cancer and approximately 39,600 women will die from the disease. This means that approximately every two and a half minutes a woman in the United States is diagnosed with breast cancer and that approximately every thirteen minutes, a woman dies from this disease. Breast cancer has become the second largest cause of cancer death in women, after skin cancer, and the leading cause of death for women between the ages of 35 and 54.

Risk factors for breast cancer:
    ? Being female
    ? Increasing age
    ? Personal history of breast cancer
    ? Family history of breast cancer
    ? Inherited genes
    ? Radiation exposure
    ? Being overweight or obese after menopause
    ? Beginning menopause after age 55
    ? Postmenopausal hormone therapy
    ? Lack of physical activity
    ? Drinking alcohol

Soy Isoflavones are a dietary supplement derived from soybeans containing phytoestrogens. These weak estrogens are chemically similar in structure to naturally produced estrogen hormones. Isoflavones are found in soy foods both with and without a sugar molecule attached. The two primary isoflavones in soybeans are daidzein and genistein and their respective glucosides, genistein and daidzein. Soy foods typically contain more genistein than daidzein, although this ratio varies among the different soy products. In cultures where soy products are consumed in abundance, women's health problems, certain cancers, and cardiovascular disease are reported to be less prevalent.

A study published in the journal Cancer Epidemiology, Biomarkers & Prevention investigated the role soy consumption plays in reducing the risk of breast cancer. Researchers enrolled 430 Asian-American women ages 20 to 55 years. They studied the usual adult soy intake and measured urinary concentrations of 15 estrogens and estrogen metabolites (EM) by using liquid chromatography-tandem mass spectrometry. The results suggested that regular soy consumption is associated with increased levels of EM. These observed variations in estrogen metabolism may decrease the risk of breast cancer.¹

¹ Fuhrman BJ, Pfeiffer R, Xu X, et al. Soy Intake is Associated with Increased 2-Hydroxylation and Decreased 16{alpha}-Hydroxylation of Estrogens in Asian-American Women. Cancer Epidemiol Biomarkers Prev. Sep2009.