As part of the Nurses’ Health Study II, 18,555 women of childbearing age shared information about their attempts to become pregnant and any fertility problems that they encountered. Over an eight-year period, the women completed questionnaires about their dietary habits, including how much and what types of dairy products they ate.
Over the course of the study, 438 women were diagnosed with infertility due to anovulation disorder (anovulatory infertility). “We found that intake of low-fat dairy foods was associated with a greater risk of anovulatory infertility, whereas intake of high-fat dairy foods was associated with a lower risk of this condition,” the authors commented.
Women who ate two or more servings per day of low-fat dairy products had almost two times the risk of infertility compared with women who consumed them once or less per week. High-fat dairy products had the opposite effect: women who had one or more servings per day of high-fat dairy products were 27% less likely to suffer from infertility than were women who ate these products once or less per week. Adding just one glass of whole milk per day cut the risk of infertility by more than one half.
Low-fat yogurt and sherbet/frozen yogurt had the most negative impact on fertility; whole milk and ice cream were the most protective.
So what about the advice to eat less saturated fat from meat and dairy products? Perhaps the answer is to concentrate on eating a diet based on whole foods—those closest to their source. Whole foods are only minimally processed, meaning that they have not been significantly altered to remove edible portions of the food, such as the bran from grains and fat from dairy products.
Emphasizing plenty of fresh fruits and vegetables, legumes, nuts, seeds, fish, and eating dairy products and lean meats in moderation provides a good balance of fats and other nutrients essential for maintaining good health and optimal fertility.