The study, published earlier this year in Cancer Epidemiology, Biomarkers & Prevention, revealed that postmenopausal women with previous breast cancer were two times more likely to have recurrence if their carbohydrate intake remained stable or increased after surgery.
While the study focused on reducing future cancer recurrences, it has tremendous implications for women who have not yet experienced breast cancer, as well as for everyone concerned about preventing cancers in the future.
Diets high in readily digested carbohydrates (like those found in most processed foods) are associated with increased cancer risks. Women who consume great amounts of high glycemic foods have a 57% increased risk of breast cancer.
This increased risk has been specifically identified in people who are overweight or obese. Overweight women, for example, are 35% more likely to get breast cancer if they eat a lot of high glycemic foods. Asian women whose primary carbohydrate source is white rice are 19% more likely to develop breast cancer with every 3 ounce increment in their rice intake per day. But those who eat brown rice, a slower-digesting starch, are 24% less likely to develop breast cancer with every 3 oz. increment of rice consumed per day. When glucose levels get so high that they enter the diabetic range, breast cancer risk grows to twice that of postmenopausal women with normal sugar levels.
In addition to increasing the risk of developing breast cancer in postmenopausal women, glycemic load and total carbohydrate consumption are also associated with the worst kinds of breast cancer, namely those lacking receptors for estrogen and progesterone molecules.
There is a deeper problem with high carbohydrate consumption, even when blood sugar levels don’t rise. “High-carbohydrate diets produce chronic elevations of insulin as the body tries to deal with the excess sugar,” said Michael A. Smith, M.D. and senior health scientist for Life Extension. "Because insulin is a growth factor, elevated insulin levels represent a potential breast cancer threat because it appears to stimulate breast cancer cells to grow and reproduce.”
The most direct way to reduce the body’s exposure to the carbohydratesthat are related to cancer risk is to eat a diet containing fewer carbohydrates and simple sugars. However, this is challenging for many people, particularly those who are also trying to reduce consumption of animal proteins and fats. Similarly, you can lower overall exposure to carbohydrate breakdown by consuming a diet high in fiber (which is not readily broken down by the intestine). But again, high-fiber diets can be unappealing and uncomfortable for many people.
A more palatable and practical option to reduce carbohydrate exposure is to use specific nutrients that limit or slow starch breakdown in the intestine, which in turn reduces blood sugar levels and insulin levels.