Relationship between food consumption and improvements in circulating melatonin in humans: an integrative review

Melatonin is an important hormone in the regulation of circadian rhythms and has great antioxidant power. Recent studies have demonstrated the benefits of its supplementation in the metabolic profile. Food sources have also been studied for complementary therapies. However, information on the bioavailability of food sources of melatonin is still scarce. Thus, the objective of this review is to gather in the literature studies that evaluate the relationship between food consumption and improvements in circulating melatonin in humans. In total, 178 studies were found, of which 11 were included in this review. The results show increases in the excretion of the melatonin metabolite (6‑sulfatoxymelatonin) or circulating melatonin for foods such as cherries, grapes, bananas, pineapples, dark green vegetables, Japanese vegetables and beer. Significant increases in melatonin were observed even after ingesting cultivars with low concentrations of this hormone. It was possible to assume that other nutrients that precede their synthesis (serotonin and tryptophan) could also have led to this increase. Although consumption of the foods found is beneficial in increasing circulating melatonin, further confirmatory studies are needed.