PCOS (polycystic ovary syndrome) is common among women of reproductive age. Hallmarks include irregular periods, insulin resistance, and an excess of male hormones. For the 40 to 60 percent of women with PCOS who are overweight, weight loss can improve symptoms. But what specific foods and nutrients play a role? What’s the best diet for people with PCOS?
FIBER: High-fiber foods can help with weight loss; increased dietary fiber has been shown to predict weight loss in women with PCOS.
GLYCEMIC INDEX: Avoiding high-glycemic-index foods—such as refined grains, sweetened beverages, fruit juices, and added sugars—is helpful for PCOS.
FATS: Saturated and trans fats (which are highest in meat, dairy, and commercial snack foods) cause insulin resistance, which worsens PCOS.
AGEs (advanced glycation endproducts): These are highly reactive molecules present in certain foods (especially when cooked at high temperatures) that can induce inflammation, insulin resistance, and cellular damage. Women with PCOS tend to have higher levels of AGEs and AGE receptors. Diets low in AGEs reduce inflammation and insulin resistance in women with PCOS. High-AGE foods include beef, pork, poultry, cheese, butter, cream cheese, and processed snack foods. Low-AGE foods include whole grains, legumes, vegetables, and fruits.
SOY: Soy has been shown to improve PCOS. A 2018 randomized trial compared a soy-containing diet with a higher-animal-protein control diet in women with PCOS. Both groups ate the same total calories, protein, carbs, and fat. Compared with the control diet, the soy diet led to significant decreases in body weight, waist circumference, insulin, insulin resistance, blood sugar, and triglycerides; it also helped counteract hormone disruption. A 2016 study found similar results.
PROTEIN: Protein from animal sources tends to promote insulin resistance and inflammation, key issues in PCOS.
BOTTOM LINE: A 2017 review study published in Diabetes & Metabolic Syndrome: Clinical Research & Reviews noted that “a favorable dietary plan in women with PCOS should contain low amounts of saturated fatty acids. … Additionally, sufficient intake of fiber-rich diet from whole grains, legumes, vegetables, and fruits with an emphasis on carbohydrate sources with low glycemic index is highly recommended.” Hmmm … sounds a lot like a plant-based diet to me!