Melatonin – Its Effects on Sleep, Aging, Cancer and More

Melatonin is a hormone synthesized in the body, which regulates sleep and influences other hormones. It’s manufactured in the pineal gland (in the brain) from the amino acid, tryptophan. Its production is largely influenced by how much light your body receives through the eyes. Here’s some meaty information on the actions, benefits and sources of this vitally important sleep hormone.

The “hormone of darkness” is secreted in…the dark. When your eyes take in bright light, melatonin production is suppressed. Although it was once thought that melatonin might regulate the sleep-wake cycle, the central nervous system is actually in charge, but sends melatonin to signal drowsiness and lower body temperature.

Light prevents secretion of the sleep hormone, but darkness tells the body that the day is over, it’s time to turn in, and time to release melatonin. The name for this natural rhythm is DLMO – dim-light melatonin onset.

In plants, the key function of melatonin appears to be its antioxidant actions. In humans, it also performs this function. Lab observations in animals showed the hormone preventing DNA damage by carcinogens, revealing it as another antioxidant that could help to prevent cancerous cells from forming.

Children have higher concentrations of the sleep hormone especially through the night, which may account for their excellent deep sleep; whereas melatonin production appears to decrease with aging and may peak earlier in the night, possibly causing sleep interruption or early waking. Studies show that some elderly produce no melatonin at all.

A study at the University of California tested the effects of dietary melatonin on aging mice. Scientists concluded that melatonin “reversed 13 of the 25 genes altered with age.” This age reversal caused “…a more youthful gene profile to brains of aged animals by melatonin.”

According to a report published by the University of Maryland Medical Center, Melatonin plays a role in regulating the menstrual cycle by helping to control release of female reproductive hormones. Taking therapeutic doses of the hormone could affect cycle regularity or the onset of menopause.

A study in Tel-Aviv, Israel found that coffee consumption repressed secretion of an important melatonin metabolite, explaining why the action of melatonin was inhibited by caffeine. Also important, the secretion of melatonin is largely regulated by environmental factors; namely, light. Anything that disrupts sleep or the natural sleep cycle can also throw off the signaling for melatonin. Common examples are jet lag, working nights, exposure to light, and even lacking sleep.

Discover Your Sleep Score

According to the Institute of Health Sciences, other hindrances could be alcohol, blood sugar imbalances, stress, electromagnetic waves as emitted from microwaves, radios and TVs, and age. The first signs of a deficiency may be sleepiness or exhaustion during daytime hours, irritability and insomnia.

It’s easy enough to supplement melatonin as there are dozens of brands available in supermarkets and drug and health food stores. You can also try some of these totally natural “tricks” to help your body produce more of the stuff on its own.

A study in Thailand observed melatonin levels and antioxidant activity after eating oranges, pineapples and bananas, which have high melatonin concentrations. The researchers wanted to see whether the presence of the hormone in fruits actually increased levels in the blood, thus benefiting human health. Results confirmed that melatonin and antioxidant capacity increased significantly in the blood after ingesting the fruits.

Other foods concentrated with the sleep hormone include tart cherries, strawberries, grapes, tomatoes, almonds, walnuts, flax seeds and sunflower seeds; corn, oats, wheat, rice and barley; and olive oil, wine and beer. You’ll notice these are mostly staples of the Mediterranean diet, recently praised as a powerfully health promoting, and easy-to-sustain, diet. While these foods don’t contain therapeutic doses, consuming them on a regular basis, while being careful not to overdo stimulants such as caffeine, could promote and help to maintain a healthy sleep cycle.

Researchers discovered that it’s blue light in sunshine that blocks the production of melatonin. Conversely, red light does not affect the sleep hormone, so keeping  a red light on for the occasional midnight bathroom excursion won’t interrupt sleep. If you’re having trouble getting to bed, jet lagged, or if you’d just like to retire earlier, try out a set of blue blocking glasses or goggles. Wearing these 1-3 hours before bed will allow you to continue to read and function with lights on in the house, but the glasses block the blue component of light, thus allowing melatonin to begin secreting. LowBlueLights.com offers eyewear for kids and adults, ipad, iphone, TV and computer screen blue-blocking filters and other products to block the blue.

Light streaming through your window or flashing from a computer screensaver can be interruptive to deep sleep. Wearing a sleep mask is an inexpensive way to cover your eyes, ensure perfect darkness, and promote melatonin production through the night. To awaken your senses when it’s time to get up, remove the mask and fill your eyes with sunshine.

Unlike vitamin D, you don’t actually have to be in the sun to receive its benefits for melatonin. A powerful way to heighten the body’s sensitivity to darkness is by increasing exposure to light during the day. Drink in as much fresh, bright sunlight during the day as possible. Contrast that with a dark, sleep-conducive room at bedtime, and your body will be more likely to signal copious amounts of the sleep hormone than if you’d had little to no light exposure through the day.

Unless you have one of the blue-blockers mentioned earlier, you’ll do well to unplug from electromagnetic waves emitted from electronics. These affect melatonin production and may supercharge you when you’re trying to wind down. Even if you fall asleep with these on, the current can affect depth and duration of nighttime Z’s.

Be careful taking melatonin supplements. Getting the right dose for you could take some trial and error. Too little won’t be potent enough, too much could leave you drowsy even after a full night’s sleep. Consult with your healthcare professional, or simply use natural means. We hope this helps. Enjoy a sunny day, and sleep well tonight!

—————–

Sources:

Tan DX, Hardeland R, Manchester LC, Korkmaz A, Ma S, Rosales-Corral S, Reiter RJ. “Functional roles of melatonin in plants, and perspectives in nutritional and agricultural science.” (2012) PMID: 22016420

Karbownik M, Reiter RJ, Cabrera J, Garcia JJ. “Comparison of the protective effect of melatonin with other antioxidants in the hamster kidney model of estradiol-induced DNA damage.” (2001) PMID: 11239965

Sharman EH, Sharman KG, Ge YW, Lahiri DK, Bondy SC. “Age-related changes in murine CNS mRNA gene expression are modulated by dietary melatonin.” (2004) PMID: 15009506

Shilo L, Sabbah H, Hadari R, Kovatz S, Weinberg U, Dolev S, Dagan Y, Shenkman L. “The effects of coffee consumption on sleep and melatonin secretion.” (2002) PMID: 14592218

“Maximizing Your Melatonin” 11/21/11 http://www.instituteofhealthsciences.com/maximising-your-melatonin/

Sae-Teaw M, Johns J, Johns NP, Subongkot S. “Serum melatonin levels and antioxidant capacities after consumption of pineapple, orange, or banana by healthy male volunteers.” (2012) PMID: 23137025

Sasseville A, Paquet N, Sévigny J, Hébert M. “Blue blocker glasses impede the capacity of bright light to suppress melatonin production.” (2006) PMID: 16842544