Overweight women have an increased risk, compared to average-weight women, of getting breast cancer after menopause. And being overweight can increase the risk of breast cancer coming back in women who have had the disease. This may be because fat cells make extra estrogen and other hormones, which might stimulate breast cell growth.
A study adds to growing evidence that gaining weight as an adult can increase breast cancer risk. Gaining significant amounts of weight as an adult increased breast cancer risk more than maintaining the same weight through adulthood—regardless of starting weight.
This means that no matter what their starting weight was, women who gained more than 60 pounds between age 20 and the time they reached menopause were 70% more likely to be diagnosed with breast cancer than those who gained fewer than 20 pounds during that same time. Weight gain after menopause was also found to increase breast cancer risk.
These results do NOT mean it's OK to be overweight as you enter adulthood. Being overweight increases breast cancer risk, period. But the results do suggest that maintaining your weight as you get older is a very smart step toward keeping your breast cancer risk as low as it can be.
Visit the Breastcancer.org Lower Your Risk section to learn more about breast cancer risk and steps you can take to lower your risk, including maintaining a healthy weight and lifestyle.