Low-fat diet doesn't reduce hormone levels significantly or reduce Breast Cancer risk in premenopausal women


NEW YORK (Reuters Health) Sept 22 - Reducing cumulative exposure to ovarian hormones has been proposed as a way to reduce the risk of breast cancer and other malignancies. But findings from a new study suggest that a low-fat/high-fiber diet, which is one way to reduce levels of such hormones, is not effective.

The results, which are published in the November 1st issue of Cancer, are based on a study of 213 premenopausal women who were randomized to follow their usual diet or to receive an isocaloric diet with a target of 20% calories as fat, total fiber of 25 g/day, and 8 or more fruit or vegetable servings per day.

Dr. Peter H. Gann, from Northwestern University in Chicago, and colleagues found that total estradiol levels fell by about 7.5% in the low-fat/high-fiber diet group. However, this change was not significantly different from 0.9% drop noted in the control group.

The intervention diet appeared to have no effect on levels of progesterone or sex hormone-binding globulin (SHBG). The results for non-SHBG-bound estradiol were nearly the same as those of total estradiol.

There was no evidence that any of the findings were differed by patient age, body mass index, baseline hormone level, and weight change, the authors state.

Although the findings suggest that a low-fat/high fiber diet has minimal effect on sex hormone levels, "the observed 7.5% reduction in estradiol could have biologic significance if it persisted over many years," the authors point out.

Still, "weight loss and weight control through midlife could be a more effective and feasible approach to dietary intervention in reducing the risk of breast carcinoma," they add.

Cancer 2003;98.


http://www.medscape.com/viewarticle/461878