The fertility problems and hormone irregularities that plague women with polycystic ovary syndrome (PCOS) may improve on a low-carbohydrate diet, according to a new study.

In polycystic ovary syndrome, a woman's ovaries develop multiple cysts. Symptoms can include excessive hairiness, obesity, menstrual abnormalities and infertility. PCOS is also believed to increase the likelihood of developing diabetes.

"Our results suggest that a moderate reduction in dietary carbohydrate may decrease insulin, and, over time, this dietary modification may lead to improvements in the metabolic and reproductive outcomes in women with PCOS, independent of weight loss," said Dr. Crystal C. Douglas, the lead investigator of the current study.

Douglas, at the University of Alabama at Birmingham, and her colleagues recruited 15 women with PCOS who were between 19 and 42 years old and ranged in weight from normal to obese.

The 11 women who were available for follow-up had each been put on three different diets for 16-day periods, separated by two three-week "washout" periods, according to the team's report in the March issue of Fertility and Sterility.

The regimens consisted of a standard diet made up of about 56 percent carbohydrate, 31 percent fat and the rest protein; an enriched monounsaturated fatty acid diet with about 55 percent carbohydrate, 33 percent fat and the remainder protein; and a reduced carbohydrate diet with about 43 percent carbohydrate and 45 percent fat and the rest consisting of protein.

Compared with the standard diet, the low-carbohydrate diet lowered insulin levels. In addition, the usual jump in insulin in response to glucose was reduced after the low carbohydrate diet compared with the enriched monounsaturated fatty acid diet.

No differences were seen in circulating reproductive hormones.

Given these findings, the researchers conclude that dietary management may be a useful addition to PCOS treatment. As they explain, high insulin levels are thought to contribute to the hormone abnormalities seen with PCOS, so reduced insulin could lead to an improved hormone profile.

Editor: Donald