With ear plugs pushed in, shades draped over his eyes, and seat fully reclined, the weary, jet-lagged traveler pulls out a sleeping pill hoping for a good night’s rest. While this scene may sound familiar to many of us, melatonin, the hormone in that sleeping pill, may be a little less familiar.

Naturally produced by the body, melatonin is essential for the regulation of sleep in our bodies and its levels fluctuate during the day, increasing when it is dark outside to tell our bodies it is time for sleep. Melatonin has also been found to fluctuate seasonally, with greater amounts of melatonin being produced in the fall and winter months when the days are shorter. New research suggests that the environment, via melatonin, plays a role in multiple sclerosis, a neurological disease affecting approximately 2.3 million people around the world.

Multiple sclerosis (MS) is a disease of the central nervous system in which the body’s immune system starts to attack myelin, a covering around nerves that helps to speed along signals across the body. The breakdown of myelin around the nerves causes a range of symptoms depending on where MS develops, including numbness, vision, speech and movement impairments, and reduced cognitive function.

After tracking 139 MS patients for a year, researchers found that during the fall and winter, when melatonin levels are naturally higher due to less sunlight, patients had a 32% lower rate of falling into a period of experiencing disease symptoms. Thus, greater melatonin levels were found to decrease the chance of an MS patient relapsing into experiencing symptoms.

It is believed that the amount of light in a person’s surroundings has an indirect relationship with the amount of melatonin that is produced; the less light there is, the more melatonin is produced, and vice versa.

Image Source:  JACOPIN /BSIP

In both mice models of MS and human culture samples, treatment with melatonin caused the production of protective immune T-cells that protect the degradation of myelin on the nerves. At the same time, melatonin stimulated the production of a protein that prevented hurtful T-cells from being produced. Thus, the researchers hypothesize that melatonin may help reduce the risk of relapsing by causing a favorable differentiation of T-cells in the body, i.e. to produce more helpful than harmful T-cells.

The researchers caution MS patients that there is a lot of research yet to be done to fully understand the controls at work here, and that they should not be going out and buying melatonin supplements right away. Further research addressing safety and mechanisms of action may prove that melatonin is an affective solution for treating MS.

Feature Image Source: Polygon Medical Animation – T Cells by Polygon Medical Animation

Alex Kim

Author Alex Kim

Alex is a third year student at UC Berkeley studying Molecular and Cell Biology and Public Health and minoring in Music. He hopes to go to medical school and to pursue a career in surgery. In his free time, Alex enjoys playing piano and guitar, running, golfing, eating (everything), and watching movies.

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