The NEJM article extols the many virtues of melatonin, including its powerful antioxidant effects, its potential benefit in preventing and treating cancer, its immune enhancement properties, its potential to slow aging, and its ability to promote better sleep and to avoid jet lag. The only real difference between articles on melatonin that have appeared in Life Extension magazine and the article in The New England Journal of Medicine are the conclusions. This conclusion shouldn't be surprising.
Medical journals are almost always extremely conservative in their recommendations.
A contradiction appearing in the NEJM article on melatonin was its criticism of people who ingest more than 300 to 500 mcg a night of melatonin, thus increasing their serum levels by 10 to 100 times the normal level found in a young person. There is evidence from experimental studies that melatonin influences the growth of spontaneous and induced tumors in animals. Pinealectomy enhances tumor growth, and the administration of melatonin reverses this effect or inhibits tumorigenesis caused by carcinogens. Data on the relation between melatonin and oncogenesis in humans are conflicting, but the majority of the reports point toward protective action. The mechanism by which melatonin may inhibit tumor growth is not known.