29 May 2012
Even moderate weight loss in overweight or obese women who are not taking hormone replacement therapy can reduce levels of circulating sex hormones that are associated with an increased risk of breast cancer.
US researchers looked at 439 overweight-to-obese women, aged 50-75 years, who were randomly assigned to one of 4 groups: exercise only, diet only, exercise plus diet and no intervention.
The randomised controlled trial found that weight loss significantly reduced female sex hormones, including oesterone and oestradiol (types of oestrogen). Oestrone levels decreased 9.6 per cent with diet and 11.1 per cent with diet plus exercise, while oestradiol levels decreased by 16.2 per cent with diet and 20.3 per cent with diet plus exercise.
"Based on previous research, our results suggest that losing just 5 per cent or more of one's weight could cut by a quarter to a half the risk for the most common, oestrogen-sensitive breast cancers," they said.
Last Reviewed: 29 May 2012