Women who reported eating more saturated fat had a higher risk of some types of breast cancer, according to a large European study.
Researchers tracked more than 337,000 women from 10 European countries. After 12 years, those who initially reported consuming the most saturated fat (roughly 48 grams a day) had a 28 percent higher risk of ER+PR+ (estrogen receptor-positive, progesterone receptor-positive) breast cancer than those who reported consuming the least (about 15 grams a day).
Women who ate the most saturated fat also had a 29 percent higher risk of HER2- (human epidermal growth factor 2-neu-negative) but not the more-aggressive HER2+ breast cancer.
The most common types of breast cancer are ER+PR+ and HER2-. ER+PR+ tumors are linked to being overweight or taking hormones after menopause, and to other signs of greater lifetime exposure to estrogen.
In a second study, which tracked 88,800 U.S. nurses for 20 years, women who consumed the most animal fat (largely from meat) when they were young adults had an 18 percent higher risk of (pre- and post-menopausal) breast cancer.
In 2006, a large randomized trial (the Women’s Health Initiative) found no lower risk of breast cancer in postmenopausal women who reported cutting their intake of all fats. However, the “lower-fat” group trimmed their daily saturated fat only slightly (by about 5 grams).
What to do: Limit your saturated fat to lower your risk of heart disease. Epidemiological studies that follow women for years can’t say whether that will also lower your breast cancer risk. Something different about women who eat more sat fat could explain their higher risk.
Sources: J. Natl. Cancer Inst. 106: dju068, 2014; Breast Cancer Treat. 145: 255, 2014.