Scientists trying to understand exactly how the hormone melatonin alleviates the ravages of metabolic conditions such as hyperlipidemia and diabetes have discovered a mechanism that suggests it could be used to rein in weight gain.
What is Melatonin?
Melatonin is a hormone that is produced by the pineal gland, a pea-like structure found in the center of the brain.
Melatonin, a hormone that regulates the sleep-wake circadian rythm
It is produced when a person is in darkness; that wave of calm that sweeps in as you sit in the dark is melatonin kicking in, instructing your body to sleep. It exerts a major effect on our circadian rhythm, and for this reason it is given to jetlagged individuals or people suffering from sleep disorders in order to reset their internal clocks or induce sleep respectively.
Besides affecting the circadian rhythm, melatonin is believed to have anti-oxidant and anti-inflammatory capabilities; these proven attributes could possibly explain why it is known to prevent neural apoptosis (cell death) in brain injuries, or how it can significantly delay the withering of plant leaves in experiments. While it will not rejuvenate one into his youth, melatonin has also shown to be a contributor to healthy aging.
Traces of it are found in coriander, almonds, cherries, sunflower seeds, fennel, cardamom, and mustards.
Melatonin supplements can be found in health food stores.
A Rodent Affair
Diabetic Zücker Rat
Scientists drawn from the Institute of Neuroscience, University of Granada, the Health Science Center, University of Texas, and the Hospital Carlos III set up an experiment using Zücker rats, which are used as models in hypertension and obesity research.
A total of 8 rats were used in the experiment, half of which were Zücker Diabetic Fatty (ZDF) rats and the other half Zücker Lean (ZL) rats. The ZDF rats exhibit conditions similar to Type 2 Diabetes- induced obesity, while the ZL rats correspond to what would be normal health conditions.
These rats were reared as littermates and after attaining five weeks of age, two groups, each containing an equal number of ZDF and ZL rats, were established. The rats in one group had melatonin administered to them through the water they drank, at a dosage of 10mg/kg/day. The control group did not have melatonin administered to them, and that was the only difference between the two groups insofar as diet was concerned.
This feeding regime lasted 6 weeks, and the researchers made several interesting discoveries. First of all, it was discovered that some white adipose tissue had been essentially converted to brown adipose tissue in the ZDF rats that were fed with melatonin. The difference between these two fats is stark, as I will elucidate shortly.
White Vs. Brown Fat
White adipose tissue is the primary site for storing excessive calories in the body. Also known as white fat, these cells usually have one large lipid droplet bound by the cell, and pretty much nothing else, except a peripherally located nucleus. These cells are flexible, and can stretch to 4 times their ordinary size to accommodate greater droplets.
Brown adipose tissues also stores lipids, but in the form of numerous droplets instead of one huge droplet. This arrangement ensures that these cells can contain more organelles, and brown fat cells are packed with mitochondria, which break down these lipid droplets in order to produce adenosine triphosphate (ATP), which is broken down to provide energy for many metabolic processes. Brown adipose tissue, also known as brown fat cells, have their brownish tinge because of the significant presence of these mitochondria.
White fat cells far outnumber brown fat cells but only a few brown fat cells can have a significant effect on the body. When stimulated, the mitochondria in brown fat cells start burning off lipids in order to create ATP, while at the same time releasing proteins such as UCP 1 and PGC-1α, which stimulate other cells into converting stored energy (lipids) into readily available forms. This results in a widespread burn of body fats.
The conversion of white adipose tissue to brown adipose tissue was confirmed by staining histological samples with hemaloxylin-eosin. Temperatures recorded during the experiment also corroborated this assessment, because it was noted that after administration of melatonin the inguinal temperature had risen by around 1.36⁰C in ZL rats, and 0.55⁰C in ZDL rats, suggesting greater metabolic activity.
ZL rats that had received a dose of melatonin were observed to have more active brown cells, which explains their higher gain in temperature.
The ZDF and ZL rats that hadn’t received melatonin did not exhibit such changes, and their temperatures were largely unchanged.
The researchers also found that melatonin-fed rats had more thermogenic activity (fat burning, heat producing processes) when exposed to acute cold or exercise.
Translating This into a Weight Loss Strategy
These results show that in all likelihood, a certain dosage of melatonin will stimulate the body into burning up a lot of its energy reserves (read fat). But melatonin should not be considered a panacea for weight loss; it should be regarded as part of a wider strategy that involves regular exercises (melatonin will make you burn more fat), and a proper diet (so that you don’t negate all your efforts).
There isn’t much literature on its long term effects, so consult a physician before taking up a regime involving melatonin; after all, it is possible more sleep hours is all you need to elevate your melatonin levels in a most natural way.