Soy Isoflavones May Help with Weight Control in Breast Cancer Survivors

July 12, 2004

A recent study in 56 postmenopausal women who were breast cancer survivors tested the effects of Soy Isoflavones versus an inactive placebo. The soy Isoflavones were supplemented at a dosage of 114mg a day for 3 months, stopped for two months (called a washout period) and then switched over to the women previously on placebo to further verify the effects. Cholesterol was not affected by the Isoflavones, but interestingly the levels of ghrelin fell significantly in the women receiving soy Isoflavones. Inhibiting ghrelin, a hormone released in the stomach that is a growth hormone releaser and an appetite stimulator, may reduce hunger levels and aid weight loss. The study is published in the July 2004 issue of The Journal of Clinical Endocrinology and Metabolism

Commentary by Jerry Hickey, R.Ph.

Researchers at the University of Washington found that the hormone ghrelin produced in the stomach, makes you hungry. Eating drops your blood levels of ghrelin and your hunger is then shut down. Interestingly, one of the effects of gastric bypass surgery for extremely obese people is that they stop producing ghrelin and their weight loss may become permanent. Normally when you loose weight by dieting, the stomach releases even greater levels of ghrelin to bring your weight back up (to an ideal level). Anything that safely aids ghrelin control is likely beneficial.

Soy-Derived Estrogens Don't Seem to Increase Cancer Risk

Monkeys who had their ovaries removed (to stop their estrogen and progesterone production) were placed on one of three diets for 3 years. One group received soy protein without Soy Isoflavones. A second group received soy protein with 129mg of Soy Isoflavones each day. The third group received equine (horse) derived estrogen at a dose scaled to equal 0.625mg (in a woman) per day in a base of soy protein (and without Soy Isoflavones).

Cell proliferation and progesterone receptor activity was much higher in the breast and uterus of the group that received horse estrogen than in the other two (the two other groups had the same results). The subjects receiving Soy Isoflavones actually had lower levels of estrogens in their blood than the other two groups showing the Isoflavones were actually protective and not just neutral. The result of receiving Soy Isoflavones showed that they reduced the risk of breast cancer in this study and also protected the uterus. The study is published in the July issue of The Journal of Clinical Endocrinology and Metabolism.

Commentary by Jerry Hickey, R.Ph.

A recent study of almost 22,000 women in the Journal of the National Cancer Institute shows that women with the highest dietary consumption of Soy Isoflavones had a 54% decreased risk of developing breast cancer and that the protection was the strongest in postmenopausal women. A different study in postmenopausal women who were supplemented with Soy Isoflavones (who didn't have soy as part of their normal diet) had better cognitive skills, attention spans and memory recall than women on placebo. The study was published in Pharmacology, Biochemistry and Behavior.

Stroke and Dementia

Another study has been published linking stroke and loss of brain function. According to this study the likelihood of developing dementia after a stroke is high. In the first years following a stroke it resembles Alzheimer's disease (the most common form of dementia). Then it shifts over to resemble vascular dementia. Researchers started followed 191 stroke patients 6 months after their stroke for 4 years. 21.5 Percent of the patients (41 patients) had developed dementia at the end of the four years. The study confirms that dementia is a frequent consequence of stroke. The study is published in the June 2004 issue of Neurology.