What is melatonin and how does it work for sleep?
Melatonin is a hormone primarily produced by the pineal gland—a pea sized gland located right above the middle of the human brain. While some people think of melatonin as a sleep aide or sleeping pill, that’s not how it works. Instead, melatonin supports a state of quiet wakefulness that helps us fall asleep.
Darkness triggers the production of melatonin, helping to regulate the body’s sleep-awake cycle (circadian rhythm). Interfering with the natural darkness-melatonin production process disrupts the sleep-awake cycle of the body’s internal clock.
Keep in mind that disruption of the circadian rhythm isn’t the cause of all sleep disorders. If you’ve been struggling with insomnia or poor quality of sleep for some time, ask your healthcare provider to help you get to the root of the problem.
Jet lag, shift work, poor sleep habits and too much screen time wreak havoc on melatonin production!
If you’ve ever traveled across several time zones, you’ve probably experienced jet lag. People who do shift work or don’t maintain a consistent sleep-awake schedule often have similar sleep issues. That’s because your body isn’t producing melatonin when it naturally would.
Too much screen time—phone, tablet, PC, TV—in the hours leading up to bed can also disrupt melatonin production. This exposure to bright light, which should only occur during daytime, now extends into nighttime. Melatonin production gets put on hold as your body fights to stay awake. Hello restless nights and groggy days.
You may be able to fix disruption of melatonin production and poor sleep due to jet lag, shift work, poor sleep habits and too much screen time by making some minor lifestyle adjustments.
- For jet lag induced by travel across multiple time zones, try staying awake until what normal bedtime would be at your new destination.
- Using artificial light during waking hours and sleeping in a dark quiet room helps some shift workers find relief.
- Of note, it is highly recommended night shift workers take melatonin daily before sleep. Because of the constant light exposure, this population people is very vulnerable to decreased melatonin production and subsequent increase in disease risk.
- Adopting a strict sleep schedule—going to sleep and waking at the same time each day, including weekends—can work wonders if you’ve been haphazard about your sleep habits.
- Putting screens away and turning off the TV an hour or two before bed can help screen time addicts get their circadian rhythms back on track.
- Those who need to monitor emails or digital media right before bed may benefit from investing in a screen protector that blocks blue light.
- If these strategies don’t work, over-the-counter melatonin supplements may help in the short-term.
- Speak with a healthcare practitioner before taking melatonin for the long-term. (More on melatonin supplement dosage and side effects below.)
Beyond better sleep: Why melatonin is essential for optimum health.
A powerful antioxidant that neutralizes free radicals and protects against cancer, diabetes, heart disease and more
One of the key areas where melatonin shines is by supporting mitochondrial function. The mitochondria act as tiny powerhouses in the cells that break down nutrients to produce energy in the cells and promote cell metabolism.
Melatonin is a highly potent antioxidant that has been shown to neutralize free radicals (molecules that inhibit cell growth and survival) produced in the cells that lead to oxidative stress. When tissues in the body are in a state of oxidative stress—essentially antioxidants are losing the war to free radicals—the cells’ detoxification capabilities are hampered, leaving the body vulnerable to disease, including:
- Certain cancers (leukemia, melanoma, breast, prostate, colorectal, gastric, lung and ovarian)
- Cardiovascular diseases
- Rheumatoid arthritis
- Chronic obstructive pulmonary disease (COPD)
- Inflammatory bowel disease
- Acquired immunodeficiency syndrome
- Huntington’s disease
- Wilson’s disease
- Viral illnesses such as colds, flu- including coronaviruses.
Mitochondria produce the bulk of free radicals (also known as reactive oxygen species) generated by the cells. At the same time, melatonin is found in higher concentrations in the mitochondria than other subcellular locations. The mitochondrial membranes also possess transporters that allow for the rapid uptake of melatonin, enabling this hormone as antioxidant to annihilate the free radicals and help prevent disease.
Melatonin plays an important role in immune function.
Melatonin has been shown to modulate immune function
Protective leukocytes (white blood cells), which help the body fight infection and disease, also work hand-in-hand with melatonin. Leukocytes are equipped with melatonin specific receptors and the enzymatic machinery required to synthesize melatonin.
Melatonin also triggers the proliferation of T-cells, which kills infected host cells, activates other immune cells and helps regulate immune response. In addition, melatonin enhances the process phagocytosis, which removes pathogens and debris from the cells. Research suggests that melatonin may provide potential therapeutic value to enhance immune function for some individuals.
Melatonin may also help regulate inflammation and fight respiratory distress.
Numerous studies support the protective effects of melatonin through its antioxidant powers, as well as its role in regulating inflammation and preventing chronic inflammation.
Through its antioxidant powers, melatonin has also been shown to inhibit NLRP-3 inflammasomes (proteins that activate the negative side of the immune system). These inflammasomes cause inflammation in the lungs often leading to respiratory distress, including that associated with COVID-19.
Proliferation of the NLRP-3 inflammasomes is also associated with diseases of the central nervous system, including:
- Cerebral hemorrhage
- Ischemic stroke
- Parkinson disease
- Glutamate associated brain damage
- Subarachnoid hemorrhage
Melatonin supports a healthy heart, brain, kidneys and nervous system.
Melatonin’s partnership with the mitochondria (the vital powerhouses in our cells) also contributes to a healthy cardiovascular system. Its role is to help regulate the function of the mitochondria in the heart, brain, kidneys and the renin–angiotensin system—the hormone system responsible for regulating blood pressure, fluid and electrolyte balance, as well as blood circulation.
Through its antioxidant powers, melatonin also plays a protective role in the brain, where it fights the free radicals that cause oxidative stress. Research suggests that melatonin may serve as a potential therapy for certain neurodegenerative disorders, such as:
- Alzheimer’s disease
- Parkinson’s disease
- Huntington’s disease
- Amyotrophic lateral scelerosis (ALS)—Lou Gherig’s disease
Melatonin may also protect against diabetes, insulin resistance and weight gain.
The protective effect of melatonin on the mitochondria has also been shown to have an impact on diabetes, insulin resistance and obesity. Research suggests that melatonin:
- Regulates glucose metabolism by inducing insulin resistance at night and insulin sensitivity during the day, which is closely associated with nocturnal fasting and daytime feeding.
- Regulates energy homeostasis, influencing feeding, energy storage and expenditure.
- Tips the energy balance in the direction of reducing food intake and increasing brown adipose tissue (also known as brown fat or “good” fat) energy expenditure, preventing excessive body weight gain.
- Melatonin influences insulin secretion and decreased blood glucose.
About melatonin supplements, dosage and side effects.
In small doses (1-5 mg/night), melatonin is generally safe for most people when taken for short periods of time. Since melatonin’s key role is to support the circadian rhythm (sleep-awake cycle)—and it may cause drowsiness—melatonin supplements should be taken about two hours prior to bedtime.
If you suffer from a melatonin deficiency (which occurs naturally as we age), work nights or suffer from an illness or disease, seek the guidance of a medical professional for dosage recommendations. Even at higher dosages melatonin is generally safe.
People who are pregnant, nursing, taking blood thinners or suffer from diabetes, high blood pressure or epilepsy should avoid taking melatonin supplements unless directed to do so by a healthcare practitioner.
When taken per the recommended dosage, the side effects of melatonin in adults are typically minor. If you suffer from melatonin side effects, a lower dose may be in order.