Melatonin Protects Against Age-Related Sleep Decline

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Melatonin is a hormone secreted by the brain, and is well known for its role in regulating sleep. Light suppresses melatonin production, while in the absence of light melatonin levels rise and promote sleep.

Why Might Melatonin Be Beneficial?

Poor sleep quality appears to accelerate ageing at the cellular level: sleep loss is associated with shorter telomeres and possible increased cellular senescence, both of which are key mechanisms underlying the ageing process. Sleep quality tends to decline with age, and this has been linked to increased risk of developing chronic diseases such as Alzheimer’s disease.

Melatonin supplementation improves sleep quality, mainly by decreasing the time taken to fall asleep, and may therefore protect against the above. Additionally, melatonin may have further protective effects in the brain due to its potent antioxidant properties. Melatonin may have a number of other benefits that are being investigated, including anticancer properties, preventing fat gain, and improving eye health.

What Is The Evidence Behind Melatonin Supplementation?

A meta-analysis of 19 trials including 1683 subjects with primary sleep disorders (sleep problems not caused by another medical condition or drug) found a significant improvement in sleep time and quality with melatonin supplementation. This finding is supported by other meta-analyses, including one showing benefit for secondary sleep disorders. Furthermore, effectiveness of melatonin did not dissipate during continued use and showed benign side effects compared with other pharmacological treatments.

Melatonin also appears to be beneficial for sleep problems caused by external stimuli, as it is able to re-establish the circadian rhythm following disruption by an altered light/dark cycle associated with jet-lag. A meta-analysis of 10 studies found melatonin to be effective at preventing or reducing jet-lag if taken close to the target bed time. Melatonin may also be beneficial to nocturnal shift workers for this reason.

Melatonin is a powerful antioxidant, outperforming resveratrol and vitamin C in preventing DNA damage from oxidative stress. It may also boost other antioxidant enzymes: melatonin reduced oxidative stress in patients with metabolic syndrome in one study, and reduced oxidative stress following exercise in another.

Safety Notice

While the side effects of melatonin are few and mild, those taking neurally active agents such as antidepressants should consult with a doctor before taking melatonin, which is likely to interact with these drugs.

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Overall, the benefit of melatonin supplementation lies in its ability to improve sleep duration and quality, for which there is convincing evidence.Melatonin also appears to be a powerful antioxidant.