Soy May Cut Endometrial Cancer Risk
Estrogen-Like Compound in Soy Beneficial for Postmenopausal Women Most
Aug. 5, 2003 -- Soy found in everyday food products may decrease the risk of endometrial cancer, a common form of uterine cancer, a new study shows.
Endometrial cancer is a rapid and uncontrolled growth of cells in the lining of the uterus. It is the most common gynecologic cancer in the United States in women 45 years and older. The cause is unknown; however, experts believe it is associated with prolonged exposure to estrogen without any progesterone.
Phytoestrogens are nonsteroidal compounds found in plants that have estrogen-like activities or are broken down by the body into compounds with estrogen-like activity. They are found in soy-based foods. Research shows that phytoestrogens may block the cancer-causing effects that high levels of natural estrogen may have on the uterus.
Researchers at the Northern California Cancer Center evaluated the associations between dietary intake of three phytoestrogens (isoflavones -- the most common type, coumestans, and lignans) and the risk of endometrial cancer in more than 1,000 women ages 35 to 79. Half were diagnosed with endometrial cancer.
Researchers assessed not only dietary intake, but also factors such as physical activity, menstrual patterns, and how often and how much the volunteers ate foods containing phytoestrogens.
Their study appears in the August 6 issue of the Journal of the National Cancer Institute.
Postmenopausal Women Benefit Most
Results showed that consumption of isoflavones and lignans, but not coumestans, were associated with a reduced risk of endometrial cancer, particularly among postmenopausal women. Obese postmenopausal women who consumed low levels of isoflavones or lignans had the greatest risk of endometrial cancer.
Foods that contain isoflavones and lignans also include:
- Whole grains
- Dried fruit
- Orange juice
Most cases (77%) of endometrial cancer are diagnosed in the earliest stage when cancer is contained in the uterus and can be cured. The primary treatment for this cancer is hysterectomy to remove the uterus, cervix, ovaries, and fallopian tubes.
Researchers conclude that certain phytoestrogens consumed at levels in the typical American diet are associated with a decreased risk of endometrial cancer.