Diet may disrupt menstrual cycle.(Brief Article)

2002 APR 11 - (NewsRx.com & NewsRx.net) -- Women whose menstrual cycle is disrupted during strenuous athletic training simply might not be eating enough, a new study suggests.

The study used female cynomolgus monkeys, which have a menstrual cycle similar to that of women. Researchers at Penn State University and the University of Pittsburgh found that by increasing food intake the subjects could reverse cases of exercise-induced amenorrhea.

Researcher Nancy I. Williams, assistant professor of kineseology and physiology at Penn State, said the menstrual disruption found in athletes was similar to that in nonathletes who simply don't eat enough. Although the exact mechanism is unclear, she said, "it's just the same as if you underfeed someone."

That triggers the brain to reduce production of certain hormones, including estrogen, disrupting the menstrual cycle.

After monitoring the normal menstrual cycles in the monkeys for a few months, the researchers taught the monkeys to run on treadmills, steadily increasing their regimen to about 6 miles per day. While the monkeys' body weight stayed roughly the same, the study found metabolic hormone levels dropped and menstruation was disrupted.

Half of the monkeys were then given additional food, and those subjects resumed normal ovulation. Those that increased their food consumption the fastest also were the first to resume normal menstruation.

Dr. Carol L. Otis of the Kerlan Jobe Orthopaedic Clinic in ...