"Wake up refreshed and full of energy," says one advertisement for melatonin. Other ads promote use of the compound for a host of health problems from obesity to insomnia. Many advertisements target older people and encourage them to take commercial melatonin preparations to restore levels lost with aging. Older Americans who do, however, have responded to a false premise in the salesman's cry, according to results of a new study that contradicts the popular notion that melatonin levels in older people fall with age.
In the study, National Institutes of Health (NIH) grantee Charles A. Czeisler, M.D., Ph.D. and colleagues at Harvard Medical School and Brigham and Women's Hospital in Boston studied 34 healthy older people, both men and women ranging in age from 65 to 81, and found that their nighttime melatonin levels did not differ significantly from those of 98 younger men whose age ranged from 18 to 30. The study, which spanned five years, appears in the November issue of the American Journal of Medicine.*
Study participants were medication free and did not have insomnia or other sleep complaints. They had to forego alcohol, caffeine, and nicotine and were also asked to keep a sleep journal. As part of their participation in the study, each person spent three days and three nights isolated under carefully controlled conditions in a sleep laboratory at Brigham and Women's Hospital. In order to minimize the effect of the experiment on their usual patterns of melatonin secretion, participants maintained their normal sleep schedules. At regular times, scientists took blood samples in order to assess melatonin production.
"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 the eighth decade," said Dr. Czeisler. "This means that in most healthy people, concentrations of mel
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Contact: Stephanie E. Clipper
clippers@exmur.nia.nih.gov
301-496-1752
NIH/National Institute on Aging
4-Nov-1999