February 28, 2006 – Researchers at the University of Alberta in Western Canada just released the results of a clinical trial meta-analysis1 questioning the therapeutic effects of melatonin in the treatment of sleep disorders.
In a recent article in the British Medical Journal, the authors report having analyzed the results of 25 clinical trials conducted from 1993 to 2003 with approximately 500 subjects. They conclude that there is no evidence that melatonin can decrease the time it takes to fall asleep, whether due to a medical cause, drug or medication abuse, jet lag or variable work schedules.
The authors of this meta-analysis nevertheless stress that their conclusion cannot be considered definitive. Several other clinical trials will have to be carried out in order to see more clearly.
Note that the same team of researchers published, in December 2005, the results of another summary of clinical trials which indicated that melatonin could be effective in reducing the time it takes to fall asleep associated with jet lag or working hours. variables2.
In their two meta-analyzes, the authors estimate that melatonin does not appear to cause adverse effects in the short term (up to three months of daily use), but they point out that the effects of prolonged use are not known. .
Research is intense in the field of the therapeutic effects of melatonin: a simple request made in Medline, the clinical data bank of the US National Library of Medicine, indicates that in 2004 and 2005, nearly thirty clinical trials were published on the effects of melatonin on various aspects of sleep disorders. The recent meta-analysis published in the British Medical Journal covered 25 of the 1,884 studies published up to 2003.
It is estimated that 10% to 20% of North Americans suffer from sleep disorders. Melatonin plays a role in circadian rhythms (metabolic adaptation to the alternation of wake / sleep). This hormone is used by many people to combat the effects of jet lag or variable work schedules. Commercial melatonin is a synthetic product, entirely manufactured in the laboratory. So-called “natural” melatonin supplements are extracts from animal pineal glands. Their use is uncommon and very controversial because of the possibilities of contamination: bovine spongiform encephalopathy (mad cow disease) or others.
Pierre Lefrançois – PasseportSanté.net
1. Buscemi N, Vandermeer B, et al. Efficacy and safety of exogenous melatonin for secondary sleep disorders and sleep disorders accompanying sleep restriction: meta-analysis, BMJ, 2006 Feb 18; 332 (7538): 385-93. Epub 2006 Feb 10.
2. Buscemi N, Vandermeer B, et al. The efficacy and safety of exogenous melatonin for primary sleep disorders. A meta-analysis, J Gen Intern Med, 2005 Dec; 20 (12): 1151-8.
