NEW YORK, Nov 05 (Reuters Health) -- Blood levels of melatonin, a hormone produced by the pineal gland deep in the brain, were thought to fall with age, prompting claims that taking supplements of the hormone might slow aging. But results of a new study contradict this theory, suggesting that melatonin levels do not fall with the advance of Father Time.
"The idea that a pineal aging clock winds down as you get older is simply not true," researcher Dr. Jamie M. Zeitzer explained in a statement.
The report, published in the November issue of The American Journal of Medicine, suggests that levels of the hormone melatonin do not decrease with age. In fact, 34 men and women aged 65 to 81 had similar melatonin levels to a "control" group of 98 men and women aged 18 to 30.
Melatonin is produced naturally by the brain's pineal gland. Because it is released into the bloodstream at night, melatonin is thought to play a role in regulating sleep. Melatonin supplements are sold in health food stores, sometimes with claims that the hormone supplements can stave off the effects of aging, jet lag, or sleep problems. Some researchers have suggested that it might help people feel younger because older people were thought to produce less melatonin naturally.
"In our analysis, we did not find any statistically significant difference in nighttime melatonin concentrations between the young and older subjects, although our study does not address whether melatonin levels change after (age 80)," explained lead researcher Dr. Charles A. Czeisler of Harvard Medical School in Boston, Massachusetts, in a written press release. "This means that in most healthy people, concentrations of melatonin in (blood) probably do not decline with aging," he added.
In the press release, issued by the National Institutes of Health (NIH) in Bethesda Maryland, which funded the study, Dr. Andrew Monjan of the National Institute on Aging noted, "To say that aging affects the regulation of melatonin secretion is not borne out by the scientific literature, especially this newest study, the most comprehensive and carefully designed to date."
Monjan added, "It is important that people understand, however, that there is some preliminary evidence that melatonin may be useful for jet lag and some types of insomnia."
"Another thing not to overlook is that commercially available melatonin remains unstandardized, unregulated, is largely untested, is expensive, and we still do not know how safe it is for long-term use, especially for older people with a variety of health problems taking a number of drugs," Monjan pointed out.
Because herbal products and nutritional supplements are not regulated by the US Food and Drug Administration, they are not held to the same rigorous testing and standards as medications. As such, exact dose, side effects, and effectiveness of these products are not well understood.
