What is it?
Melatonin is a neurohormone, secreted by the pineal gland in the brain and it regulates the sleep/wake cycle. Light suppresses melatonin synthesis.
It is also found in a variety of foods, although typically in small amounts such as tomatoes, walnuts and some cereals like barley and rye.
Function & Benefits
As a hormone, melatonin’s main function is to promote the onset and maintenance of sleep. It achieves this by activating melatonin receptors in the brain, which inhibit neuronal activity and regulate the body’s circadian rhythm. Melatonin receptors have been identified in many other organs as well (including the digestive tract, pancreas, and immune cells), which may explain some of it’s other health effects.
The primary use of melatonin supplements is to normalise abnormal sleep patterns.
It may also ease symptoms of irritable bowel syndrome, reduce tinnitus severity, lower blood sugar levels in people with type 2 diabetes, and result in small (perhaps negligible) amounts of weight loss.
There is ongoing research for it’s use as adjunct treatment in cancer.
Some individuals tend to have irregular melatonin production or metabolism. Smokers may be less responsive to supplementation due to increased melatonin breakdown of the molecule, and older people seem to produce less melatonin during night time. That is probably why not everyone benefits from supplementation.
Finally, one meta-analysis suggests that melatonin supplementation may modestly improve symptoms of depression. While melatonin is likely safe and potentially useful for depression and anxiety, more research is needed.
The current evidence is strongest for it’s benefits on improving sleep issues associated with jet lag and social jet lag, including the athletic population.
Dosage & Timing
For regulating the sleep cycle and improving sleep disorders, doses of melatonin between 300 micrograms (mcg) and 5 mg have been shown to work.
One can start with 300 mcg, and work up to 5 mg as needed. The most effective dose is an area of ongoing research.
Remember: The benefits of melatonin are not dose-dependent — taking more will NOT help you fall asleep faster.
To help with sleep, you can take it roughly 30 minutes before going to bed, although some people may benefit from taking melatonin as much as 3 hours earlier.
Safety
There are two important things to keep in mind when it comes to the safety of melatonin supplementation: First, many melatonin supplements often do not contain the amount claimed on the label (sometimes containing substantially more), and second, some supplements could be contaminated with serotonin, a neurotransmitter with unclear safety when ingested orally.
Supplementing melatonin doesn’t appear to affect the body’s own production in a negative way.
Clinical trials on males have found that melatonin supplementation up to 6 mg per night does not reduce testosterone levels.
It also appears safe for use in children and adolescents.
Takeaway:
Overall It appears to be safe and effective as a sleep aid. Always discuss with your healthcare team if it is the right supplement for you and if yes, what should be the dose and duration, specially if you are on medication for other conditions.
Always try to enhance other factors related to good sleep hygiene first for eg., exposure to gadgets before and during melatonin supplementation.
~ Shwetha Bhatia, Registered Dietitian (Indian Dietetic Association)