Study Shows Weight Loss May Reduce Risk of Breast Cancer

By Emily Murray

New information released by researchers from the Fred Hutchinson Cancer Research Center has shown that perhaps moderate weight loss can help reduce the risk of developing breast cancer.

As mentioned in an ABC News article on the study, there has long been a suspected correlation between obesity and breast cancer risk in women, specifically once menopause sets in. This has been believed since the fatty tissue is actually a large source of estrogen, which is often linked to tumor development, specifically in the breasts. With this in mind, it stands to reason that the lower the percentage of fat tissue, the lower the amount of this estrogen in the body. This assumption was the basis for the latest study.

Study author Dr. Anne McTiernan found that if women moderately lose weight through healthy measures like diet and exercise, the risk of breast cancer can be reduced by nearly 50%.

While the idea of losing weight appeals to most women, attaching a number or weight loss goal can be rather challenging. As a result of this study, researchers have made it clear that drastic weight loss isn’t necessary to lower the risk of breast cancer. While obesity on it’s own has a variety of health complications, in order to reap the benefits mentioned in this study, losing as little as 5% total body weight can be enough. Of course, when more was lost there was typically a significant decrease in risk as well.

The Study

The Seattle-area was home to the study subjects involved in the research. There were 439 postmenopausal women who were either “sedentary and overweight or obese.” After dividing the women into 4 groups, their results were recorded.

The 4 groups were as follows –

1.) Intensive weight loss program with a focus on calorie and fat reduction through eating fruits and high-fiber veggies.

2.) Intensive exercise only program (45 minute aerobic classes 5 times a week)

3.) Exercise (light walking) and diet changes

4.) No change in diet or exercise (later they were offered weight loss classes at the completion of the study.

The Results 

One year later the average weight loss of those dieting was 10.8% of their body weight, the women who added exercise as well lost an average of 11.9%. the exercise only group was around 3.3% and the control saw slight increase in weight.

While the changes in the amount of weight loss varied slightly in the groups the most interesting factor the authors saw was that estrogen and hormone levels dropped the most in those who modified diet and exercise, therefore leading to an overall decrease in cancer risk. While these women were only studied for a year and were not tracked to see who actually developed cancer later on and who did not, it is still believed that this research can help offer insight into lifestyle changes that can help reduce the risk of cancer.