Wednesday, September 25, 2013

Can melatonin help you lose body fat? by Jerry Brainum

Melatonin is a natural hormone secreted by the pineal gland in the brain. Melatonin is synthesized through a series of enzymatic steps starting with the presence of the essential amino acid, L-tryptophane. The tryptophane is converted into serotonin, which is a brain neurotransmitter, and then converted into melatonin. This happens at night, and melatonin has long been associated with sleep onset. In fact, it's sold as an over the counter food supplement for that purpose. Besides being available in food supplement form, melatonin is also found naturally in small amounts in various foods, such as fruits, vegetables, cherries, almonds, mustard, and other foods. Besides its use as a sleep aid, melatonin also has been shown in various studies to be useful in treating diabetes, elevated glucose levels, and elevated blood fats. It is considered safe when used in moderate amounts. The usual dose for sleep onset purposes is 1-5 milligrams, taken an hour prior to sleep. Any more than this results in extreme morning grogginess. As you might expect, since melatonin promotes the stages of deep sleep, it also promotes growth hormone release during sleep. One study published a few years ago found that when young men ingested melatonin prior to exercise, they showed significant elevations in growth hormone release during exercise. This, however, is not advised, since melatonin will make you feel sleepy, and thus is not conducive to intense training.
     While having excess body fat is considered antithetical to good health for a number of reasons, there is one type of fat that is beneficial. Known as brown adipose tissue or simply, "BAT," this type of fat provides a potent thermogenic action, converting excess calories into heat. This tends to help keep body fat levels lower. While humans were previously thought to express BAT only during infancy, more recent research has found that BAT is more active in adults than previously believed. Some suggest that BAT explains why some people can consume more calories than others, yet not get fat. Another type of fat recently discovered is known as beige adipose tissue. Similarly to regular BAT, this type of fat is thermogenic, but doesn't contain as any mitochondria (where fat is oxidized) as the usual form of BAT. But the beige fat does contain higher amounts of the same thermogenic protein found in BAT, namely uncoupling protein-1 or UCP-1. White adipose tissue or the usual type of fat found in the body, can be converted into beige fat through exposure to cold. But according to a new study, another way to convert white fat into more active beige fat is by providing melatonin.
   The study involved both diabetic fat rats, as well as normal, thin rats. Providing melatonin to the rats increased the sensitivity to cold exposure (thus producing more beige fat), as well as boosting the thermogenic effect produced by exercise. The researchers who conducted this study were surprised to find that melatonin produced these beneficial effects in both the diabetic obese rats as well as the thin normal rats.The amount of melatonin supplied to the rats was 10 milligrams per kilogram of bodyweight, but this would be modified for a human dose, and thus humans would need ingest a far lower dose to get the same effect as the rats. Precisely how much hasn't yet been determined. The levels of UCP-1, the primary thermogenic protein in BAT and beige fat, doubled in the rats provided with melatonin. Melatonin also boosted the levels of another protein called PGC-1A, which promotes the development of additional mitochondria, by 25% in the lean rats, and more than double in the fat rats.
    While this research looks promising, it must be kept in mind that it involved rats, not humans. While the existing mechanisms also occur in humans, whether melatonin will produce similar effects remains to be studied. In addition, the ideal human dose for this purpose also needs to be determined before melatonin can be recommended as a fat-loss aid.


   Jimenez-Aranda, et al.

Melatonin induces browning of inguinal white adipose tissue in Zucker diabetic fatty rats. J Pineal Res 2013: in press.

 ©,2013 Jerry Brainum. Any reprinting in any type of media, including electronic and foreign is expressly prohibited.

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