Melatonin is a hormone that is created in the human pineal gland, a pea-sized gland located just above the middle of the brain. Part of its crucial role is to regulate the circadian rhythm and therefore modulate the sleep-wake cycle.
As well as reducing the time it takes to fall asleep and improving the quality of sleep, melatonin may also be effective at reducing anxiety. A paper entitled “Facilitation of Benzodiazepine Discontinuation by Melatonin” states that, “controlled-release of melatonin may effectively facilitate discontinuation of benzodiazepine therapy while maintaining good sleep quality.” Benzodiazepine is prescribed by doctors for disorders such as anxiety and insomnia. Yet ironically, as reported by Drugs.com, “unusual sleep behaviors and anterograde amnesia may occur” as a potential side effect of taking the drug. And because sleep is an absolutely essential state that gives the body the down time it needs to heal, melatonin offers many more benefits beyond reducing anxiety and giving you a good night’s sleep.
Shedding A Light On Insomnia
Bright light exposure directly inhibits melatonin production, since the pineal will not release the hormone unless a dimly lit environment is provided. In low light and darkness melatonin is pumped into the blood stream and levels rise briskly, lowering alertness and welcoming sleep.
Reset spoke to Dennis Hill, who has a degree in biochemistry from the University of Houston and has worked in medical research at the University of Texas’ M.D. Anderson Hospital, about melatonin’s role in the human body and sleep cycles.
“Melatonin in humans and other animals is a hormone that synchronizes sleep and is also an effective antioxidant,” Hill explains. “Melatonin is synthesized in the pineal gland from L-tryptophan. Synthesis begins in the evening as dusk descends, then ends with the dawn. In this way, melatonin can be used therapeutically in circadian rhythm sleep disorders. Norepinephrine regulates melatonin. As light stimulates norepinephrine, melatonin is diminished; as light recedes, norepinephrine no longer inhibits melatonin production. Melatonin is ultimately cleared from the body by the liver.”
Hill specifies exactly what factor allows light levels to dictate the production of the hormone: “It is not full daylight that is the inhibitor of melatonin, but just blue light in the spectrum of 460 to 480nm. This allows for some clinical management of the melatonin bioactivity with blue-blocking lenses.”
Western culture has become extremely accustomed to its inhabitants spending many evenings sat in dark rooms, facial features illuminated by blue-light emitting screens. Such exposure into the late hours of the night has been shown to suppress melatonin production, and can lead to chronic insomnia. A post entitled “Insufficient Sleep Is a Public Health Problem” on the Centers for Disease Control and Prevention website states that, “An estimated 50-70 million US adults have sleep or wakefulness disorder.”
The Dark Side Of Night Light
Harvard Health Publications, the media division of the prestigious Harvard Medical School, released a Harvard Health Letter titled “Blue light has a dark side.” The report notes that, “Study after study has linked working the night shift and exposure to light at night to several types of cancer (breast, prostate), diabetes, heart disease, and obesity. It’s not exactly clear why nighttime light exposure seems to be so bad for us. But we do know that exposure to light suppresses the secretion of melatonin, a hormone that influences circadian rhythms, and there’s some experimental evidence (it’s very preliminary) that lower melatonin levels might explain the association with cancer.”
Without the right setting for slumber, our bodies cannot properly benefit from the deep healing that naturally occurs during sleep, nor can we fully access the other biological benefits of melatonin. But whether it’s external or internal factors that cause a lack of melatonin in those suffering from sleep disorders, there is undoubtably a correlation between lack of sleep and disease. This is perhaps because melatonin also happens to be an extremely powerful antioxidant with potential cancer fighting properties.
Hill explained this mechanism to Reset: “In its identity as an antioxidant, melatonin is a wide-spectrum free radical scavenger that can cross the blood-brain barrier as well as cell membranes. In this capacity, melatonin is highly effective in quenching singlet oxygen species in the mitochondria that is generated during the mitochondrial synthesis of adenosine triphosphate (ATP). Beyond this, even the metabolites of melatonin become an anti-oxidative cascade.”
The Healing Power Of Melatonin
Antioxidants, such as melatonin, are powerful molecules that harbor the ability to neutralize rogue and damaging molecules within the body known as free radicals. Free radicals inflict biological distress in the form of oxidative damage. According to the Center for Environmental and Health Science in Sydney, Australia, “Evidence is accumulating that most of the degenerative diseases that afflict humanity have their origin in deleterious free radical reactions. These diseases include atherosclerosis, cancer, inflammatory joint disease, asthma, diabetes, senile dementia and degenerative eye disease.”
A paper from the University of Texas Health Science Center explains that, “Melatonin’s functions as an antioxidant include: a), direct free radical scavenging, b), stimulation of antioxidative enzymes, c), increasing the efficiency of mitochondrial oxidative phosphorylation and reducing electron leakage (thereby lowering free radical generation), and 3), augmenting the efficiency of other antioxidants.”
The paper goes on to add that, “There may be other functions of melatonin, yet undiscovered, which enhance its ability to protect against molecular damage by oxygen and nitrogen-based toxic reactants.”
Oxidative stress caused by free radical damage is a likely contributor towards numerous neurodegenerative diseases. A paper from Ankara University in Turkey states that, “Oxidative stress has been implicated in the development of neurodegenerative diseases like Parkinson, Alzheimer’s disease, Huntington’s disease, epileptic seizures, stroke, and as a contributor to aging and some cancer types.” In the paper, aside from remarking on melatonin’s “free radical scavenger and antioxidant properties,” the author also notes its ability to regulate the activity and expression of other antioxidant and pro-oxidant enzymes.
Because of this property in particular, melatonin has shown promise as a potential cancer treatment for various forms of the disease. Researchers at the University of Cantabria in Spain released a paper which explores the link between breast cancer and the oncostatic (anti-carcinogenic) actions of melatonin. The authors of the study state that melatonin “regulates the activity of the aromatases, the enzymes responsible for the local synthesis of estrogens, thus behaving as a selective estrogen enzyme modulator.”
This ability to control the production of estrogen means melatonin is promising as a potential treatment for cancers that are dependent upon excess estrogen, such as certain types of breast cancer. The authors of the University of Cantabria study conclude that, “The same molecule has both properties to selectively neutralize the effects of estrogens on the breast and the local biosynthesis of estrogens from androgens, one of the main objectives of recent antitumor pharmacological therapeutic strategies. It is these action mechanisms that collectively make melatonin an interesting anticancer drug in the prevention and treatment of estrogen-dependent tumors, since it has the advantage of acting at different levels of the estrogen-signaling pathways.”
This multi-functional and powerful pineal hormone has also shown to be effective at limiting prostate cancer cell growth. The University of Texas Health Science Center published a paper that opens with the statement: “Melatonin, the main secretory product of the pineal gland, inhibits the growth of several types of cancer cells. Melatonin limits human prostate cancer cell growth by a mechanism which involves the regulation of androgen receptor function but it is not clear whether other mechanisms may also be involved.”
The study involved a number of both androgen-dependent and independent prostate cancer cells which were treated with melatonin. It was found that both types of cells reduced in number and ceased cell cycle progression. The authors of the paper conclude that, “Melatonin markedly influences the proliferative status of prostate cancer cells.”
Furthermore, a review published by a team based at McMaster University in Canada, which analyzed randomized controlled trials (RCTs) of melatonin in solid tumor cancer patients, also found the hormone to be highly beneficial. In particular, the researchers looked at how melatonin affected the survival rate during the first year of the disease. 10 RCTs and a total of 643 patients were observed. Based on the outcomes, the authors stated that, ”The substantial reduction in risk of death, low adverse events reported and low costs related to this intervention suggest great potential for melatonin in treating cancer.”
Maximizing Your Melatonin
Our bodies naturally produce melatonin, however, as mentioned previously, there are numerous factors that may restrict optimal production. Below are certain techniques that are proven to enhance our body’s ability to produce the hormone, as well as ways to prevent environmental factors from impairing it.
Meditate: The vast catalog of health benefits that this age old mental technique offers seems to be ever increasing. Boosted levels of melatonin appear to be another advantage that comes with the long term practice of meditation. A paper from Ulleval University Hospital in Norway documents a study that measured both plasma melatonin and blood serotonin concentrations in advanced male meditators before and after an hour long meditation. The authors conclude, “The findings suggest that advanced meditators have higher melatonin levels than non-meditators.” However, the researchers noted that the effect wore off after an hour and that, “Melatonin decreases during long meditation.” So if you’re looking to use meditation to boost melatonin, it may be best to keep your practice short and sleep sweet!
Expose yourself to daylight: A Harvard Medical School publication states that exposure to bright light during the day will boost the bodies ability to sleep during night time hours, as well as contributing to feelings of well-being and alertness during the day time. Exposure to daylight keeps our internal body clock, or circadian rhythm, in balance, thus resulting in improved melatonin secretion during proper sleeping hours.
Avoid bright lights two to three hours before bed time: Using electronics with bright screens prior to bed time can suppress melatonin secretion. All types of light will contribute towards this suppression, however blue light is the worst culprit. As red lights have the least effect on shifting circadian rhythm, it is advised to use dim red lights at night time and especially before sleeping. Glasses containing blue-blocking lenses can also be utilized when using electronic devices before bed time in order to filter out the melatonin suppressing rays of blue light.
Eat Cherries: A study conducted at the University of Rochester Medical Center in New York looked at the effects of tart cherry juice on older adults suffering from insomnia. The juice was associated with significant improvement in all of the variables measured in comparison to placebo, including a significant reduction in insomnia severity. The study was then repeated with the intent of measuring melatonin levels. The authors concluded that, “These data suggest that consumption of a tart cherry juice concentrate provides an increase in exogenous melatonin that is beneficial in improving sleep duration and quality in healthy men and women and might be of benefit in managing disturbed sleep.”
It is important to note that sweet cherries have 50 times less melatonin than tart cherries. Other foods high in melatonin include walnuts, bell peppers, flaxseeds and tomatoes.
Eat foods high in tryptophan: Serotonin, derived from the amino acid tryptophan, is a precursor to melatonin. Tryptophan is an essential amino acid and has the ability to cross the blood-brain barrier. Foods high in tryptophan include: spirulina, spinach, watercress, bananas, and sunflower seeds.