Melatonin is a hormone that plays an important role in your natural sleep cycle. Your brain (more specifically, the pineal gland) produces this hormone in the evening. It acts on your body’s receptors to encourage sleep. Many studies suggest that melatonin supplements might be helpful in improving quality of sleep in many sleeping disorders such as Insomnia, delayed sleep phase and even jet lag.
Sleep dysfunctions and sleep disorders are highly prevalent in the elderly.
Age-related sleeping disturbances can be caused by many different factors: changes in lifestyle (such as retirement), certain medical and mental conditions which occur with age, poor sleeping habits and pre-existing sleeping disorders. Many of these factors are correlated with a disturbance in melatonin production.
Melatonin levels have been shown to decline gradually over the course of human life. This can result in lower sleep efficacy and disruption of the circadian rhythm. During old age, the circadian changes that affect body functions become less striking. This correlates with a similar pattern of decreased melatonin levels (as shown the figure below).
Older people exhibit advanced sleep phase syndrome which presents with symptoms such as early sleepiness and early morning awakening. This condition can occur in part due to reduced light exposure. Therefore, bright light therapy is one of the suggested treatment options that may help.
Melatonin also has many immunomodulatory properties. Its decline with age plays an important part in the process of aging. Also, since melatonin is a potent free radical scavenger, its decline with age may cause a reduction in the antioxidant effects which may contribute to the incidence and severity of some age-related diseases.
A review published in 2017 showed that melatonin supplements helped reduce the time it takes for people with insomnia to fall asleep. It also helped reduce delayed sleep phase syndrome which is when your circadian rhythm is out of sync and your sleep cycle is delayed. People with sleep phase syndrome can’t fall asleep until more than two hours past their usual bedtime. Melatonin supplementation was also shown to help in regulating sleep-wake patterns in blind people. However, a review paper published in 2019 suggested that the evidence of the effectiveness of the use of melatonin for insomnia and circadian rhythm related sleep disorders is low and questioned by some guidelines.
And this leads us to the concept of Chronotherapy. it is based on the use of melatonin along with other sleep hygiene practices to produce a synergistic effect and restore the optimal circadian pattern of sleep-wake cycle.
These practices include using melatonin and bright light in combination. This has been shown to augment the amplitude and synchronicity of the circadian rhythm.
The clinical effects of melatonin and chronotherapy have been clearly demonstrated in many placebo-controlled trials in disorders associated with diminished melatonin levels such as: circadian rhythm related sleep disorders, insomnia in children with neurodevelopmental disorders, poor sleep quality, jet lag, nocturnal hypotension and Alzheimer’s disease.
Getting exposed to sunlight during the day is essential because your body needs a certain amount of sunlight to produce serotonin which is a precursor of melatonin. This sets our circadian rhythm to produce melatonin at night.
We all have the habit of using our phone before bed, the blue light emitted from our phones disrupts the natural production of melatonin which may have negative effects on the quality of sleep.
Due to melatonin’s essential role in improving sleep, adding melatonin to your diet may improve sleep, Some of these foods include:
Certain fruits (apples, bananas, peaches, avocado, cherries) have the highest content of melatonin. Dairy products, eggs, fish ,turkey and chicken contain melatonin. Some nuts and seeds (almonds, peanuts, cashew, walnuts) and vegetables (spinach, broccoli and onions). Mushrooms are also good sources of melatonin.
To reap the benefits of sleep enhancing foods it's best to consume them 2 to 3 hours before bed time.
But is there evidence that they actually work in reducing sleep disorders?
Sweet cherries (30g of sweet cherries or 200-400g pitted have been shown to help some people with reducing awakenings at night. The same goes for Kiwis take before bed.
A safe dose of melatonin is the lowest dose that helps you sleep without causing side effects. In general, 0.2-5 mg is 30 to 60 minutes before bedtime is considered a safe dose to start with.
In general, studies on animals and humans have shown that short term use of melatonin is safe and may only cause minor side effects such as dizziness, headaches, nausea and sleepiness. Similarly, randomized clinical trials have indicated that long-term use of melatonin supplements may only cause minor side effects when compared to placebo. Due to lack of studies, it is not recommended for pregnant and breastfeeding women.
Regular melatonin tablets come as fast (or immediate) release tablets which means that they release melatonin instantly into your bloodstream or can be found as extended release tablets which dissolve more slowly mimicking the way your body naturally secretes melatonin. Extended release tablets are thought to be better for maintaining sleep during the night. Your doctor may be able to help you decide which is better for you.
Sleep disorders in the elderly: a growing challenge
Kamalesh K. Gulia Velayudhan Mohan Kumar
Melatonin, human aging, and age-related diseases
Elderly as a High-risk Group during COVID-19 Pandemic: Effect of Circadian Misalignment, Sleep Dysregulation and Melatonin Administration
Daniel P. Cardinali, Gregory M. Brown, [...], and Seithikurippu R. Pandi-Perumal
Evidence for the efficacy of melatonin in the treatment of primary adult sleep disorders
Fiona Auld et al. Sleep Med Rev. 2017 Aug.
Melatonin and sleep disorders: Overview of literature and testing in psychiatric practice
S Huysmans et al. Tijdschr Psychiatr. 2019.
Influence of Dietary Sources of Melatonin on Sleep Quality: A Review
Nádia Pereira et al. J Food Sci. 2020 Jan.