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Sleepytime tea? Melatonin, a hormone secreted by the brain’s pineal gland and associated with getting a good night’s sleep, is one of the natural products whose popularity has waxed and waned in recent years. A number of inconclusive studies have led some to question the efficacy of melatonin — especially overly strong commercial formulas that tend to overwhelm brain receptors — in promoting better sleep.

However, a new study by Irina Zhdanova, a MED associate professor of anatomy and neurobiology, and colleagues at MIT, Hadassah Medical Center in Jerusalem, and the University of Glasgow, has shown that melatonin treatment can significantly reduce the time it takes to fall asleep, as well as increase sleep efficiency, measured by the amount of time spent sleeping proportionate to time in bed, and increase the overall duration of sleep.

The researchers used a technique known as meta-analysis. They analyzed data from 17 previously peer-reviewed and published studies, involving a total of 284 subjects. All the studies were randomized, double-blinded, and placebo-controlled — that is, subjects were chosen at random, some were given melatonin, others a “sugar pill,” and neither the researchers nor the subjects knew who got the “real” pill. In addition, all the studies used objective measures to evaluate sleep. Aside from that, the studies differed considerably. Seven used subjects who were healthy volunteers, six studied insomniacs, one studied artificially induced insomnia, one studied a combination of institutionalized and independently living insomniacs, one studied schizophrenics, and one studied patients with Alzheimer’s disease. The age and sex of subjects as well as the drug formulations and the doses provided also varied considerably. A meta-analysis accommodates such differences. In this case, for each outcome measured, the study looked only at the difference between the average response on melatonin and the average response on the placebo.

Zhdanova’s research supports the effectiveness of melatonin in increasing sleep efficiency and duration and decreasing the time it takes to fall asleep. According to the researchers, further study is needed to determine optimal dose and time of melatonin administration, but they are confident that melatonin may be just what the doctor ordered to treat insomnia, particularly associated with aging.

This research was reported in the February issue of Sleep Medicine Reviews.

Hold the herbs? The 1990s saw an enormous increase in the number and kinds of dietary supplements taken by people in the United States. Their growing popularity generated concerns about efficacy and safety among health-care professionals. A research team led by Judith P. Kelly, an epidemiologist at MED’s Slone Epidemiology Center, has conducted a rigorous assessment of recent trends in the use of nonprescription supplements. The Slone Center, founded in 1975, has conducted numerous studies on the health impact of medications and other factors.

The researchers analyzed data from 8,470 randomly selected adults interviewed over the phone about their use of prescription and over-the-counter medications and dietary supplements. They compiled data on which supplements were taken, why, how, and how often during the week before the interview, and the total duration of use. Substances derived from plants or algae were defined as herbal supplements; other natural products studied were amino acids and enzymes and products derived from sources such as animal organs or marine exoskeletons.

Although the use of dietary supplements increased from 14.2 percent of the adult population in 1998 and 1999 to 18.8 percent in 2002, the researchers found that the use of most individual herbal or natural products actually decreased. Their results indicate that the overall increase was based entirely on growing consumption of lutein, an antioxidant that may lower the risk of macular degeneration and that has been added to many popular multivitamin formulas in recent years. Nearly a quarter of U.S. adults now use multivitamins daily, a regimen that has been recommended by the American Medical Association. The trend to include herbal supplements in these mainstream products is continuing with the addition of lycopene, another antioxidant that has been associated with a reduced risk of cancer.

The study suggests that supplement users are more likely to be women, white, well-educated, and of high socioeconomic status. It also indicated that the dietary supplements of choice changed over time, with Ginko biloba, Panax ginseng, and St. John’s wort declining in recent years, and chondroitin and glucosamine increasing.

This research was published in the February 14 Archives of Internal Medicine.

"Research Briefs" is written by Joan Schwartz in the Office of the Provost. To read more about BU research, visit


15 May 2003
Boston University
Office of University Relations