Study: Aging doesn't decrease melatonin

Published: Saturday, November 06, 1999

WASHINGTON {AP} If you're getting old, the TV ads suggest, you need to pop some melatonin pills.

After all, this hormone so important for a good night's sleep has long been thought to decrease with age.

Now a study funded by the National Institutes of Health suggests the dogma was wrong that healthy older people produce just as much of the sleep hormone as young people.

"We never anticipated the result we found," said Dr. Charles Czeisler of Harvard Medical School, lead researcher of the study published Friday in the American Journal of Medicine. "The conventional wisdom was that melatonin levels decline with age some referred to it as the 'aging clock."'

The new study, Czeisler said, means older Americans shouldn't believe those ads that urge popping over-the-counter melatonin supplements starting at age 40.

"There's no point in replacing something that's not missing," he said.

Melatonin is a natural hormone produced by the pineal gland deep in the brain. It is produced at high levels during a person's normal sleeping hours, and as the body starts to wake up, the melatonin levels drop. It's all part of the body's sleep-wake clock.

Some other studies do suggest melatonin can treat jet lag and certain other causes of insomnia. The study by Czeisler and co-author Jamie Zeitzer did not examine that.

Instead, it addressed whether just getting older means you have less melatonin, a serious question since so many older Americans do have sleeping problems and many take melatonin supplements, said Dr. Andrew Monjan of the NIH's National Institute on Aging.

"We have the culture now of self-medication based upon what may be pseudo- or quasi-scientific claims," Monjan cautioned. This study "clearly shows sleep problems in older people cannot be explained primarily on the basis of melatonin decreases with age."