Melatonin is primarily known as a sleep hormone, but the substance deserves a lot more attention. Studies show that melatonin can step up the body's fat burning capacity, reduce nocturnal hunger, and counteract weight increase in postmenopausal women.
Melatonin is a hormone that gets produced in the brain's pineal gland during our sleep. The substance controls our 24-hour clock (circadian rhythm) and our sleep pattern, and it has many general functions in the metabolism, hormonal balance, immune system, and digestion. As we grow older, our melatonin production slows down. It may also drop all of a sudden during menopause. Most people suffering from sleep disturbances are known to produce too little melatonin. The reduced melatonin secretion may affect our health in various ways and increase the risk of untimely hunger and weight problems. However, a melatonin supplement could compensate for this.
Melatonin and fat burning
A melatonin supplement is able to help the body burn more fat. This was seen in a study of healthy, obese rats with type-2 diabetes who were either given melatonin supplements or placebo (dummy pills).
In the rats that got melatonin there was limited storage of white fat cells, which is otherwise a cause of overweight. At the same time, their weight grew less dependent on their food intake and activity level.
According to the researchers who conducted this study, melatonin stimulates the brown fat tissue which, in contrast to white fat tissue, can convert calories from food into heat. The scientists find it plausible that the same is the case in humans.
The reason why brown fat cells have their brown color is that they contain a lot of mitochondria, which are the small powerhouses that produce energy. Although the amount of brown fat cells in older people is reduced to a few grams, they are still greatly important for the metabolism and heat production of the body. Studies even show that people with comparatively much brown fat tissue are statistically prone to lower BMI (Body Mass Index) and are less susceptible to type-2 diabetes.
White fat cells: Serve as protection (cushioning) and energy storage. Too much white fat tissue causes overweight and TOFI (thin-on-the-outside-fat-on-the-inside), a condition where a person's weight is normal but the fat percentage is too high. White fat tissue that accumulates around the digestive organs is particularly harmful.
Brown fat cells: Are found in much smaller quantities. They convert calories into heat. Studies suggest that melatonin supplements may activate the brown cells.
Untimely hunger at night
Women who overeat late in the night may suffer from a syndrome where their melatonin production is too low and out of order. This causes an increased production of the stress hormone cortisol and a hormone called ghrelin that stimulates hunger. These hormonal imbalances may lead to an uncontrollable intake of calories at night. Although overweight and overeating may be caused by a number of factors, people with disturbances in their 24-hour rhythm and too little melatonin may consider a melatonin supplement as a way of preventing untimely hunger. Women have more sensitive hormonal systems than men because they are designed for childbirth, and this may even have a negative effect on their melatonin production.
Did you know that...
Melatonin is a natural substance that is found in limited amounts in foods like cherries, bananas, and oats?
Menopause and overweight
Menopause normally sets in around the age of 45 to 55 years and is known to cause a drop in sex hormones that may lead to hot flushes and other symptoms. It is normally believed that a lack of estrogen is the main cause of reduced appetite and weight increase. However, there is evidence that a drastic reduction of the melatonin production may have an even greater influence on body weight. A study divided 90 women into three groups: One group consisted of women who were premenopausal and still had their normal periods. Another group included menopausal women without changes in their weight or appetite. The third group also consisted of menopausal women, but they had increased appetite and weight. Each study participant had her levels of estradiol, FSH (follicle-stimulating hormone), and melatonin measured. The study showed a significant relation between lack of melatonin and weight increase in menopausal women. According to the researchers, supplements of melatonin may be worth considering in the case of such hormonal imbalances.
Lack of sleep, blood sugar levels, and overweight
Lack of sleep increases the amount of stress hormone, resulting in an emergency situation where the body taps into its own resources in order to function in the daytime. A study of healthy slim men revealed that as little as four nights with four and half hours of sleep reduced insulin sensitivity and thereby the cells' ability to take up sugar from the bloodstream. This condition is also known as insulin resistance and is one of the contributing factors of chronic diseases such as type-2 diabetes.
Other studies have shown that the risk of developing type-2 diabetes increases by as much as 50 percent in people who generally don't sleep well or sleep too little.
Good sleep together with healthy eating habits and exercise are extremely important if you want to obtain or maintain your ideal weight. In this connection, melatonin is not only important for our deep sleep and especially our REM sleep (Rapid Eye Movement) that allows us to recharge our batteries, physically as well as psychologically. Melatonin is also important for our digestion and numerous metabolic processes, all of which help control our weight and general well-being.
Ewa Waleca-Kapica et al. Melatonin and Female Hormone Secretion in Postmenopausal Overweight Women. International Journal of Molecular Sciences. 2015
Jiménez-Aranda A et al. Melatonin induces browning of inguinal white adipose tissue in Zucker diabetic fatty rats. J Pin Res 2013 E pub ahead of print
Brown Fat Cell Discovery May Lead To Treatment of Obesity. Sci-news.com 2013
Toffol E et al. Melatonin in perimenopausal and postmenopausal women: associations with mood, sleep, climacteric symptoms, and quality of life. Pub Med gov. 2014
Pierpaoli Walter, Regelson William. The Melatonin Miracle. Simon and Schuster 1996
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