Melatonin & chronobiology

© Chronobiology

    

Recent studies in chronobiology have indicated that melatonin supplements can help treat circadian sleep disorders as well as a variety of sleep-related issues. However, not all melatonin supplements are created equal. The way melatonin supplements are metabolized can have a huge effect on physiological levels and effects of this hormone.

Melatonin and the Circadian Rhythm

Melatonin, also known as the "mother hormone of chronobiology", is a hormone made in the pineal gland due to cues from the suprachiasmatic nucleus of the hypothalamus, which regulates the circadian rhythm. When the retinas stop sensing as much blue wavelength light, the suprachiasmatic nucleus senses this and induces the pineal gland to begin making melatonin. When early morning light is sensed by the retinas, melatonin production is ceased and hormones associated with wakefulness are made instead. This cycle helps to create a circadian rhythm, or 24-hour sleep-wake cycle.

Melatonin has a very short half-life, of about thirty minutes. Because it breaks down so quickly, it must be made continuously throughout the night in order to sustain restful sleep. In people with a healthy circadian rhythm, melatonin levels rise rapidly after dark and plateau throughout the night until early morning. These high levels are essential not just for falling asleep, but for sleeping deeply and restfully. Melatonin levels then drop sharply in the early morning to allow people to wake up in response to increasing light levels.

Melatonin Supplements and Sleep

Studies in circadian biology have shown how important melatonin levels are to maintaining a natural human sleep-wake pattern. In fact, studies have found that many sleep disorders improve significantly with melatonin supplementation. However, some people find that melatonin doesn't work as dramatically as they expected. They may assume that melatonin is not a useful treatment for their sleep issues when in fact, they could be simply taking the wrong kind of melatonin supplement.

The most common types of melatonin supplements are fast release and slow release. Fast release melatonin causes a sharp spike in melatonin levels that drops off after an hour. People who use this type of melatonin supplement may find that they are immediately sleepy but have trouble remaining asleep or do not get high quality sleep. Slow-release melatonin, on the other hand, takes hours to build up to sleep-inducing levels and then does not wear off in the early morning. People who take slow release melatonin may have trouble falling asleep due to low melatonin levels, followed by difficulty waking up because the levels are unnaturally high.

Timed-Release Melatonin: A Better Option for Maintaining Natural Circadian Rhythms

Timed-release melatonin is a supplement that is formulated to be released in amounts that mimic healthy, natural melatonin levels. It is metabolized so that levels rise sharply after the supplement is taken and then remain at a high plateau for several hours. Levels then drop sharply to allow for waking. This mimics the healthy, normal circadian rhythm cycles that are linked to restful sleep.

Research in chronobiology has shown that maintaining melatonin cycles is important not just to restful sleep but to overall health. For this reason, an increasing number of health experts are recommending timed-release melatonin as the ideal melatonin supplement. It more closely correlates to the natural levels of melatonin in a healthy brain. Maintaining a healthy circadian rhythm is important to health, so timed-release melatonin supplements are usually the best option.