Consuming a Mediterranean diet rich in anti-inflammatory compounds from whole grains, vegetables and extra virgin olive oil can help dampen inflammation.Anastasia Timonina/iStockPhoto / Getty Images
Polycystic ovary syndrome (PCOS) is one of the most common hormonal disorders affecting women of child-bearing age. It’s a frequent cause of female infertility and also carries significant health risks for women beyond the reproductive years.
There is no one diet, per se, for managing PCOS. However, diet and lifestyle changes are considered the first-line treatments. Making such modifications can help lessen PCOS symptoms, reduce its associated health risks and improve reproductive outcomes.
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About PCOS
Several factors, including genetics, are thought to be potential causes of PCOS. As such, the symptoms of PCOS can vary among women.
Infrequent or missed menstrual periods or anovulation (when an egg doesn’t release from the ovary during a menstrual cycle) are defining features of PCOS.
So, too, is the excess production of androgens, hormones that control the development of male traits. This hormonal imbalance leads to hirsutism (excess hair growth on the face or body), acne and thinning hair on the scalp.
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It’s estimated that at least half of women with PCOS have obesity. Many also have insulin resistance, a condition when the body’s cells don’t respond well to insulin to clear sugar from the blood stream.
Women with PCOS are at increased risk of infertility, pregnancy complications, Type 2 diabetes, metabolic syndrome, sleep apnea, depression, anxiety, eating disorders, non-alcoholic fatty liver disease and endometrial cancer.
Weight management key
Weight loss is the most effective strategy to manage PCOS in women who were overweight or obese. Studies show that a 5 to 10 per cent weight loss can improve insulin resistance, ovulation and pregnancy rates.
To achieve weight loss, international evidence-based guidelines for the management of PCOS, released in 2018, recommend consuming 500 to 750 fewer calories per day, depending on personal daily calorie needs and physical activity.
There’s no consensus on the optimal diet for managing PCOS. Research suggests a number of dietary approaches are beneficial.
Diet strategies for PCOS
A 2021 review of 20 randomized controlled trials found that low-carbohydrate and low-glycemic-index diets, as well as the DASH and Mediterranean diets, improved fertility and reduced androgen levels in women with PCOS.
When the researchers looked at each diet separately, low-carbohydrate diets (about 40 per cent of daily calories from carbohydrate) tended to be better for optimizing ovulation, improving pregnancy rate and reducing the risk of miscarriage.
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A randomized controlled trial published earlier this year found a Mediterranean diet low in carbohydrate to be an effective PCOS treatment for women who were overweight.
The 12-week study compared two calorie-restricted diets and found that a Mediterranean diet with 20 per cent carbohydrate calories was superior to a low-fat diet for losing weight, reducing body fat, lowering blood triglycerides and improving insulin resistance. Both diets were effective at restoring the menstrual cycle.
The researchers attributed the advantages of the Mediterranean/low-carbohydrate diet to its higher fibre content. The fibre in whole grains leads to lower and slower rises in blood glucose.
Consuming a Mediterranean diet rich in anti-inflammatory compounds from whole grains, vegetables, fruit, nuts, pulses and extra virgin olive oil can also help dampen inflammation, which is associated with PCOS.
Some research has found a low glycemic diet to be helpful at reducing androgen levels, improving ovulation and decreasing insulin resistance. Foods with a low glycemic index, like fibre-rich whole grains, are digested more slowly and help control insulin levels.
Examples of low glycemic foods include grainy breads with seeds, steel cut and rolled oats, 100-per-cent bran cereal, brown rice, wild rice, sweet potatoes, pasta, apples, citrus fruit, berries, pears, beans and lentils, nuts, yogurt, milk and soy milk.
Do supplements help?
The best studied supplement for PCOS is inositol, a natural compound found in grains, meat, citrus fruit, beans and lentils. As a supplement, it’s available as myoinositol or D-chiro-inositol.
Inositol supplementation has been shown to improve glucose control, lower blood cholesterol and triglycerides and increase ovulation rate in some women with PCOS.
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Inositol, generally well-tolerated, is given in doses of one to four grams daily, often in combination with folic acid. Consult your health care provider to determine if inositol is suitable for you.
Physical activity important
Women with PCOS are encouraged to get at least 150 minutes a week of moderate-intensity physical activity (e.g., brisk walking at 4 mph) or 75 minutes per week of vigorous-intensity exercise (e.g., jogging, spinning, hiking).
Resistance training is recommended two (nonconsecutive) days a week.
Regular exercise can help improve insulin sensitivity, body composition and mood.
Leslie Beck, a Toronto-based private practice dietitian, is director of food and nutrition at Medcan. Follow her on Twitter @LeslieBeckRD