Working with influences of genetics and the environment on the internal clock of the body, the hormone melatonin controls the biological functions of sleep regularly, metabolism and immune function. Based on a rat study which was published in the December 2003 issue of Endocrinology, surgical removal of the gland which secretes melatonin can result to gain in weight. Obese rats who receive melatonin supplementation lose their weight with no changes in their consumption of food.
As a response to the signals from the control center of the brain for the internal clock of the body, the pineal gland produced and releases melatonin. Secretion of melatonin is higher during nighttime since the light inhibits the release of melatonin. Also, secretion of melatonin differs with age. In line with the Journal of Clinical Pharmacology, there is a rapid decline in the synthesis of melatonin which occurs between 6 and 20 years old. Later, this stabilizes between 20 and 40 years old and gradually declines after 40 years old.
Function of Melatonin
Melatonin has an effect on the daily cycles of the body including metabolism, sleep and body temperature. Such influence is done by way of a feedback communication between the brain and the glands that produce the hormone. Additionally, in 2003, a review of the research which was published in Sports Medicine indicated that melatonin has influence on the function of the kidney in the maintenance of water balance.
The body has the capacity to break down food into carbohydrates, fats and other nutrients necessary for growth of cells, repairs as well as energy. Biochemical reactions transform extra carbohydrates into glycogen and store it into the muscles and liver. If the level of blood glucose decreases, the body utilizes the stored glycogen for energy. In consistent with the rat study which was published in the January 2000 issue of Life Science, test subjects on melatonin who utilized carbohydrates and fats in the diet have better energy and glycogen storage is preserved.
Management of healthy weight needs a balance between the calories consumed and energy utilized by the body. The Endocrinology study revealed that melatonin which was administered to rats with diet high in fat can reduce the development of fat tissue. Melatonin can also decrease hyperglycemia and increase the levels of insulin in the blood. These are some of the risk factors of diabetes related to obesity. A regular dose of melatonin taken an hour before bedtime was known to be the most effective method for weight loss. As a consequence, levels of leptin which is a hormone that influence the storage of fat in the body are reduced in the blood.
Take note that the effect of melatonin would only last for a short time. Biochemical reactions taking place in the liver eliminate 99% of melatonin 5 hours after its administration. This is stated in the study published in the February 2008 issue of the Journal of Clinical Pharmacology. The timing of supplementation can have an impact on how melatonin works well. The Endocrinology study revealed that the body weight is reduced by 5.1% if melatonin is used an hour before dark. If melatonin is administered 4 hours after daylight in mice, there is no considerable change in the weight of the body.
Melatonin is capable of reversing the effect of reduced physical activity as well as age on metabolism. According to the review in Sports Medicine, there is a significant reduction in the temperature of the body which can be seen in younger women who have higher levels of melatonin. But this reduction is not observed in women who are in the post-menopausal stage. On the Endocrinology study, rats that have melatonin have lesser brown-fat deposits compatible with thermal response for the reduction of body fat.