"Glycemic load" of diet tied to breast cancer risk
Over the course of about 17 years, 2952 women developed breast cancer and, according to the investigators, glycemic load "was significantly positively associated with risk of overall breast cancer." Women with higher glycemic load diets were more apt to develop breast cancer.
In addition, carbohydrate intake, glycemic index and glycemic load were all positively associated with risk of a certain type of breast tumor - namely, estrogen receptor (ER)-positive/progesterone receptor (PR)-negative breast cancer.
Women with the highest "glycemic index diet" had a 44% increased risk of developing ER+/PR- breast cancer compared to women with the lowest glycemic index diet.
Women in the highest category of "glycemic load" had an 81% increased risk of ER+/PR- tumors, and those with the highest carbohydrate intake had a 34% increased risk, compared to those in the lowest groups.
The investigators speculate that high-glycemic load diets may boost breast cancer risk by increasing concentrations of insulin and sex hormones in the body, which may contribute to the development and spread of breast cancer cells.