DASH diet helps treat effects of PCOS

Polycystic Ovarian Syndrome (PCOS) affects as many as 18% of women worldwide. Despite its name, it is an endocrine (hormonal) disorder that is not directly caused by the ovaries; in fact, it is a combination of several different hormonal and metabolic disorders.

The name itself describes a fairly common effect of the disorder: multiple cycsts on the ovaries that are believed to represent failed ovulation, which is also reflected by the infrequent or completely absent menstruation and infertility that is a symptom of the syndrome. Women with PCOS might not necessarily have cysts on their ovaries, but they do usually have increased levels of androgen (symptoms of which include excess body or facial hair or acne), and some level of Metabolic Syndrome, which includes high insulin levels, insulin resistance, and a tendency toward abdominal obesity, which put them at higher risk of developing type 2 diabetes.

This combination of disorders also causes poorer cholesterol scores as well as higher markers of oxidative stress (inflammation), which is likely to contribute to PCOS sufferers' higher risk of breast, endometrial, and ovarian cancers.

There is no specific cure for PCOS, but some symptoms may be relieved by weight loss and exercise along with oral contraceptives and medications to help control blood sugars. Researchers in Iran noted that there have been reports that a 5% loss of body weight in obese women with PCOS seemed to help alleviate symptoms, as did a low-glycemic-index diet. Since the DASH diet (Dietary Approaches to Stop Hypertension) has been shown to help treat type 2 diabetes and metabolic syndrome in addition to high blood pressure, they wondered, would a DASH diet also help treat the symptoms of PCOS (Nutrition 2014;30(11-12):1287-1293)?

To find out, they recruited 96 clinically overweight or obese women with PCOS between the ages of 18 and 40 to participate in an 8-week dietary trial. The women were randomly assigned to one of two diets: a low-glycemic-index diet or a DASH diet. Both diets were designed to provide 52% of calories from carbohydrates, 18% from protein, and 30% of calories from total fat, and were calibrated for each woman's caloric needs at levels designed to induce moderate weight loss. Each woman was counseled with respect to the requirements of their assigned diet and were given sample 7-day menus to help them with meal planning, then every two weeks the participants filled out 3-day food diaries to help the researchers assess their adherence to their assigned diet. At the start and end of the trial the researchers measured the women's blood sugars, cholesterol scores, antioxidant capacity (total antioxidants present in body fluids), and glutathione (an antioxidant) levels along with their weight.

After assessing the women's food diaries at the end of the 8 weeks, the researchers could see that the two groups ate essentially the same amounts of carbohydrates, protein, and fats, but those following the DASH diet consumed more whole grains (but fewer grains overall) and far less sugar, along with more vegetables, fruits, nuts, seeds, and legumes. Women on the DASH diet lost more weight (over twice as much, on average), and had lower triglycerides and insulin levels along with higher levels of antioxidant capacity and higher levels of glutathione.

What this means for you

It's good to see more specific dietary recommendations for PCOS other than "lose weight," and even better that the DASH diet, which is so helpful for so many other conditions, is that recommendation.

First posted: October 22, 2014