One simple lifestyle change lowers risk of breast cancer
Losing just a little bit of weight can reduce levels of circulating estrogen that lead to breast cancer. Researchers from Fred Hutchinson Cancer Research Center, in a first study, showed high risk post-menopausal women who lost just a little weight also lowered their levels of sex hormones that increase breast cancer risk.
Weight loss and diet combo best for thwarting breast cancer
The intervention is a drug-free; simple approach that any woman can accomplish. Medications taken to thwart breast cancer block estrogen receptors but have side effects that are intolerable for some. The study showed diet and exercise to reduce body fat and weight can have a positive effect for lowering a woman's risk for the disease.
The researchers explored data from four groups of women from the Seattle area who were sedentary, overweight or obese; age 50 to 75. At the end of the study sex hormones were measured, including estrone, (estradiol and free estradiol); two types of testosterone (total testosterone and free testosterone.)
The women were assigned exercise – primarily brisk walking - diet, exercise plus dieting or no intervention.
Women who exercised and who exercised and dieted both met the goal of 10 percent weight-loss.
After weight loss all of the women had lower hormone levels, but the results were greater for women who dieted and exercised.
Anne McTiernan, M.D., Ph.D said in a press release, “The amount of weight lost was key to changes in hormone levels. The biggest effect was through diet plus exercise; exercise by itself didn’t produce much of a change in weight or estrogen.” For the long-term she recommends women do both to keep weight off and keep estrogen levels down.
Researchers suspect breast cancer risk goes up 30% for women who are overweight and also have a gene variant that is expressed in breast tissue. Findings published May, 2011, from Northwestern Memorial Hospital, found a link between the FTO gene that everyone has. Women who have a variant of the gene are more prone to obesity and breast cancer.
McTiernan cautions that the finding only applies to overweight or obese women who are not taking hormone replacement therapy.
Losing just 5 percent of body fat that contributes to estrogen production had a beneficial effect for raising levels of a protein known as SHBG that binds to sex hormones and makes them less biologically active; in turn lowering the chances of breast cancer. The finding is published in the Journal of Clinical Oncology.
Eat plenty of fruits and vegetables, cut your calorie intake, consume plenty of fiber and walk briskly to lose weight.
The finding shows weight loss and diet to reduce body fat – even if it’s just 5% - is a simple drug-free intervention for lowering breast cancer risk
Journal of Clinical Oncology
"Reduced-Calorie Dietary Weight Loss, Exercise, and Sex Hormones in Postmenopausal Women: Randomized Controlled Trial"
May 21, 2012, doi: 10.1200/JCO.2011.37.9792
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