Researchers have found that the chances of women developing breast cancer are strongly dependent upon the amount of weight one gains after the age of 18. This conclusion was drawn from the study (started in 1992) involving 62,000 post-menopausal women. As estrogen (a hormone) is already a known risk factor for breast cancer, women taking hormone replacement therapy were not included in the study.
At the beginning of the study all the participants (between ages of 50 and 74 years) were enquired about their present weight and their weight when they were 18 years old. Thereafter, the participants were followed-up for several years to enquire about development of any new cancer. The researchers found that women who gained between 21-30 pounds of weight after age 18 were at 40% more risk of developing breast cancer as compared to women who gained no more than 5 pounds. Also, the risk doubled if one gained more than 70 pounds.
According to the researchers fat cells are capable of synthesizing estrogen, a hormone that can help breast cancer to grow. Therefore, the more a woman gains weight, the higher will be the estrogen levels.
The findings indicate that breast cancer is strongly linked to weight gain; hence it becomes all the more important for women to maintain healthy body weight throughout life.