Melatonin's ability to aid sleep may also have applications in diseases like Alzheimer's. [Photo: Bigstock]

Melatonin – more than just a sleep remedy?

16 January, 2018

Natural Health News Supplementing with melatonin could help with more than just sleep problems, according to a new review.

Melatonin’s main function is to separate day and night in the body’s internal biological clock. This hormone is produced as night falls, preparing the body for sleep by lowering the blood pressure and body temperature.

Since darkness is a trigger of melatonin, strong fluorescent lights – and even ‘eco-friendly’ LED lights – are known to interfere with its production. But other factors can also stop the body making it, including anxiety and depression. The efficiency of the circadian system, and thus melatonin production can also decrease with age and in certain diseases, according to a new review published in the British Journal of Pharmacology.

Supporting the ageing brain

What you need to know

» A recent review of the benefits of melatonin supplements suggests it may be able to support the ageing brain.

» While melatonin is mostly known as a supplement that can aid occasional sleeplessness or jet lag, a wider look at the evidence suggests that it could help boost melatonin production which naturally declines as we age.

» Boosting melatonin in older people not only aids sleep, it appears to have other beneficial functions including a protective effect on the brain, clearing toxic beta-amyloid plaques associated with Alzheimer’s disease.

The review, which explores the relationship between melatonin and health as we age, suggests that supplementing the hormone might have broad health benefits.

“Deviant circadian rhythms and poor sleep quality are associated with increased risks of cardiovascular, metabolic and cognitive diseases, as well poor quality of life and increased risks of premature death,” says lead researcher Dr Nava Zisapel, of Israel’s Tel Aviv University.

“The brain structure changes with age,” says Zisapel, whose company Neurim Pharmaceuticals, produces prolonged release melatonin supplement called Circadin, “and may lose the ability to produce melatonin if the pineal gland becomes calcified. It doesn’t happen to everyone at the same age, but in general, people who begin to get grey hair are losing the ability to produce melatonin.”

Help for Alzheimer’s?

In particular the review looks at evidence for melatonin supplementation in Alzheimer’s disease (AD).

With Alzheimer’s the build-up of beta-amyloid plaque in pre-clinical AD has been correlated with poor sleep quality, while early neuropathological changes at this stage of AD are accompanied by lower melatonin levels.

Studies also suggest that sleep disruption may reduce the body’s ability to clear toxic beta-amyloid plaques, particularly in an area of the brain known as the precuneus, which is involved in the speed of reaction time to a verbal memory task.

Research into melatonin supplements has shown that they may help realign a person’s circadian rhythm and sleep, and can improve cardiovascular and cognitive health, including in patients with Alzheimer’s disease, who may start producing less melatonin in the early stages of their illness.

One intervention study reviewed found improved cognitive function in people with mild to moderate AD using 2milligrams/ day (mg/d) of prolonged release melatonin over 6 months.

Though encouraging, more studies are needed to prove this effect. Nevertheless, Zisapel says, clinically meaningful effects of melatonin treatment have been demonstrated in placebo-controlled trials in humans, and the balance of evidence to-date warrants further research in this area.