WEDNESDAY, Oct. 16 (HealthDay News) -- Cinnamon has long been used to add flavor to sweet and savory foods. Now, preliminary research suggests the spice may also help jump-start irregular menstrual cycles in women affected by a common infertility disorder.

A small study by researchers from Columbia University Medical Center in New York City found that women with polycystic ovary syndrome who took inexpensive daily cinnamon supplements experienced nearly twice the menstrual cycles over a six-month period as women with the syndrome given an inactive placebo. Two of the women in the treated group reported spontaneous pregnancies during the trial.

"There is a lot of interest in homeopathic or natural remedies for this condition," said study author Dr. Daniel Kort, a postdoctoral fellow in reproductive endocrinology at the medical center. "This may be something we can do using a totally natural substance that can help a large group of patients."

The study was scheduled for presentation Wednesday at a meeting of the International Federation of Fertility Societies and American Society for Reproductive Medicine in Boston.

An estimated 5 percent to 10 percent of women of childbearing age have polycystic ovary syndrome, with up to 5 million Americans affected. Polycystic ovary syndrome, which involves many of the body's systems, is thought to be caused by insensitivity to the hormone insulin. Typical symptoms include menstrual irregularity, infertility, acne, excess hair growth on the face or body, and thinning scalp hair.

Treatment for polycystic ovary syndrome currently includes weight loss, ovulation-inducing drugs such as clomiphene (brand name Clomid) and diabetes medications such as metformin, said Dr. Avner Hershlag, chief of the Center for Human Reproduction at North Shore University Hospital in Manhasset, N.Y.

Kort said that it's not yet clear exactly why cinnamon may work to regulate menstrual cycles in those with polycystic ovary syndrome, but it may improve the body's ability to process glucose and insulin. Prior research among diabetic patients suggested the spice can reduce insulin resistance.

Of the 16 patients who completed Kort's trial, 11 were given daily 1,500-milligram cinnamon supplements and five were given placebo pills. Diet and activity levels were monitored, and patients completed monthly menstrual calendars.