Phytoestrogens Shown to Lessen Endometrial Cancer RiskCarmia Borek, PhD
(DrEddyClinic News) Endometrial cancer is associated with prolonged exposure to estrogens without cyclic exposure to progesterone. Isoflavones in soybeans and lignans in flax have weak estrogenic effects, and by binding to estrogen receptors in cells block estrogen's ability to promote cell division that may lead to cancer.
In a study published in the Journal of the National Cancer Institute, researchers at the Northern California Cancer Center report a link between phytoestrogen intake and a reduced risk of endometrial cancer.* Investigators collected data on food consumption from 500 women, 35 to 79 years old, who were diagnosed with endometrial cancer, documenting their food intake one year prior to diagnosis.
These were compared to 470 matched controls. The questionnaire included the intake of three classes of phytoestrogens in food: isoflavones (including genistein and daidzein), coumestans, and lignans.
Isoflavone and lignan intake was inversely related to the risk of endometrial cancer: the highest consumption of isoflavones (about 2.7 mg or more) and lignans (about 0.2 mg or more) reduced endometrial cancer http://www.dreddyclinic.com/forum/viewforum.php?f=74
risk by approximately half compared to controls. Postmenopausal women showed the most benefit. The protection by phytoestrogens, previously observed for soy intake, suggest that phytoestrogens in soy are the compounds responsible for the associated cancer preventive effects.
* Horn-Ross PL, John EM, Canchola AJ, Stewart SL, Lee MM. Phytoestrogen intake and endometrial cancer risk. J. Nat. Cancer Inst 2003 Aug 6;95(15):1158-64.