One out of ten women of childbearing age deal with polycystic ovary syndrome or PCOS, a condition induced by imbalanced reproductive hormones. The imbalance affects ovulation and disrupts menstrual periods. Small sacs of fluid called cysts sometimes develop, and infertility is common. Women with PCOS often have elevated insulin levels, which leads to complications including insulin resistance and obesity. Studies suggest that the best PCOS diet is one that helps regulate insulin and weight. Evidence shows specific eating patterns that emphasize certain foods have the potential to alleviate symptoms.
Dietary Approaches to Stop Hypertension (DASH) Diet
Whole foods are unprocessed or minimally processed and free of artificial additives; examples include vegetables, fruits, legumes, meats, and unrefined plant oils. The DASH eating plan is one regimen that highlights these foods, and a 2015 study in Hormone and Metabolic Research observed that this diet promotes abdominal fat loss, lowers inflammation, and increases insulin sensitivity.
Obesity and depression often accompany PCOS. The ketogenic or keto diet has shown promise as an effective way to lose weight quickly and relieve mental fog. The keto diet calls for a drastic reduction of carbohydrates and makes the body use ketones from fat, instead of glucose from carbs, for energy. This PCOS-friendly diet can help decrease insulin resistance, which affects fertility.
Low GI Diet
The glycemic index classifies foods according to their potential to raise blood glucose levels. High GI foods with a score of at least 70 spike blood sugar, inducing a rush of insulin production. Low GI foods, with a GI under 55, cause a slower rise in blood glucose levels and a smaller insulin release. Diets rich in foods with a low GI can benefit people with PCOS because the consumption of these foods helps normalize insulin production. Researchers in a clinical trial published in the American Journal of Clinical Nutrition found that women with PCOS who participated in a low GI diet experienced greater insulin sensitivity and menses than the control group. The test group also lost an average of seven percent of their body weight.
Fruits are a sweet addition to a PCOS diet. While they do contain carbohydrates, natural sugars are more complex than processed sugar, so the body does not break them down as quickly as it would refined carbohydrates. The body must also digest the fiber in fruit to utilize the fructose. The fiber, vitamins, minerals, and other phytonutrients in fruit can help improve PCOS symptoms and insulin sensitivity. U.S. dietary guidelines suggest at least two cups of fruit daily. Fruits with edible skin, such as berries and apples, usually have a lower glycemic index. The body takes longer to digest them, and glucose and insulin levels are less likely to spike or crash suddenly. A serving of fruit could be:
- 1 small apple
- 1 orange
- 1 cup strawberries, grapes, or cherries
- 1 large peach
- ½ of a large banana
- 2 small plums
Foods for the Thyroid
The thyroid is responsible for maintaining metabolic processes. Recent research associates thyroid disorders with PCOS. A German study found that Hashimoto’s thyroiditis, which causes the immune system to attack the thyroid, is thrice as prevalent in women with PCOS than in women without the condition. A sluggish thyroid is a risk factor for weight gain. Selenium, iodine, and zinc are important trace minerals for thyroid health, and supplementation of these nutrients can enhance thyroid hormone production. Saltwater fish, Brazil nuts, turkey, shrimp, poultry, and oatmeal are rich in these nutrients.
Alpha-lipoic acid (ALA) is a naturally occurring compound present in animal and plant foods. The antioxidant can help regulate body weight. A 2018 Turkish study showed that supplementation with ALA resulted in improved menses, fewer ovarian cysts, and higher progesterone levels. Foods rich in alpha-lipoic acid include animal organs such as the liver, kidney, and heart; vegetable sources include broccoli, spinach, peas, tomatoes, and Brussels sprouts.
Folates, part of the vitamin B group, function in the metabolism of homocysteine, and a deficiency can cause homocysteine levels to rise, a common issue among women with PCOS. Research associates elevated homocysteine with a greater risk of reproductive problems, cardiovascular disease, and stroke related to insulin resistance. Folates from whole foods can help lower homocysteine levels. Significant sources include legumes, spinach, asparagus, broccoli, and avocado, which supply between 20 and 50% of the recommended daily allowance. Folic acid, the synthetic version of folate available in supplements, is effective for some people.
Up to 85% of women with PCOS are deficient in vitamin D. Observational studies link low vitamin D levels with insulin resistance, reproductive abnormalities, obesity, heart disease risk, and non-fatty liver disease. A 2019 study noted that vitamin D supplementation has a beneficial effect on liver health and insulin resistance in women with PCOS who are overweight. Adequate exposure to sunshine helps the body produce its own vitamin D. Fatty fish such as salmon, mackerel, tuna, and fish liver oils are among the few dietary sources. The nutrient is present in small amounts in egg yolks, cheese, and some mushrooms. Fortified foods including milk and breakfast cereals also contain vitamin D.
L-carnitine is an amino acid with antioxidant and anti-inflammatory properties that plays a vital role in cellular energy production. PCOS correlates with low levels of this nutrient. Recent research published in Reproduction, Fertility, and Development suggests that L-carnitine helps enhance endocrine function by lowering oxidative stress and inflammation. The best sources of L-carnitine are animal products; red meats generally contain higher amounts of amino acids. Beef, poultry, fish, and full-fat dairy products can provide this nutrient in a PCOS diet.
Gut microbiome diversity is lower in women with PCOS compared to healthy women. According to a 2018 study, an excess of male hormones, and hyperandrogenism, may cause this reduction. This condition is common with PCOS and is largely responsible for abnormal hair growth and infertility. A Johns Hopkins study suggests probiotics may enhance gastrointestinal microbiota populations. Fermented foods are rich sources of probiotics and organic acids that support gut health. Sauerkraut and kimchi, as well as fermented beverages such as kefir and kombucha, can bring variety and notable nutritional benefits to a PCOS diet.