- August 19, 2015
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- Posted by: admin
Obesity in the current era is highly recognized health issue of our time. But unfortunately it is just considered as being fat, the metabolic consequences is far beyond understanding of a lay man. According to 2012 World Health Organization report, there are more than 1.4 billion overweight adults worldwide, of whom around 500 million are obese with 40 million children under the age of 5 are overweight or obese (1).These statistics are especially alarming because of the long list of obesity- associated conditions which includes diabetes, hypertension, hypercholesterolemia, heart attacks and also increase risk for cancers.(2)
Accumulation of fat is a result of a prolonged imbalance between energy intake and expenditure. One might think that reducing fat in obese individuals could be easily achieved by either decreasing food consumption or increasing energy expenditure, unfortunately this task is not easy to achieve, in large part because of the combination of sedentary lifestyle and the availability of calorie-dense, inexpensive food.
With the exception of bariatric surgery, most anti obesity interventions that target energy intake result in moderate and often temporary weight loss. Sadly medicines aimed at loosing weight have not being effective for long term and sustainable weight loss. Notably, physical activity, the most physiological approach to burning energy, is not easy to sustain over the long term.
Very recently, a new weight loss strategy has been proposed that harnesses the energy burning properties of brown adipose tissue (BAT). Although BAT deposits have long been assumed to regress shortly after birth, recent studies have revealed that human adults possess BAT in the cervical –supraclavicular (i.e. neck, the most common location), perirenal/adrenal, paravertebral regions as well as around major arteries.(3) BAT has been shown to decrease with increasing BMI, percent body fat, age and plasma glucose levels(4). Cold induced BAT activation stimulates lipolysis (burning fat). Free fatty acids released from fat stimulate thermogenesis. This information is necessary to develop safe and effective medicines to stimulate BAT thermogenesis (5). A promising strategy may involve transforming the more abundant white fat cells into tissue that behaves like BAT, the so called “beige” or “brite” (brown in white) fat.(6)
Finally, since energy balance is tightly controlled by homeostatic mechanisms, the body may compensate for a sustained cold-induced activation of BAT thermogenesis by inducing hunger or increasing the metabolic efficiency of other tissues such as the muscle.
In other words, we may end up with chilled, yet obese people hunting for food. Not so cool after all! In conclusion, this valuable information regarding BAT, activation of this tissue can be used to improve systemic glucose homeostasis and increase energy expenditure.
An unexpected ally in the BATtle against obesity has entered the arena.
1. World Health Organization. Obesity and overweight. Fact sheet no. 311. WHO Media Centre. Updated August 2014. Available from http://www.who.int/mediacentre/factsheets/fs311/en/. Accessed 4 September 2014
2. Bray GA, Bellanger T. Epidemiology, trends, and morbidities of obesity and the metabolic syndrome. Endocrine 2006;29:109–11
3. Cypess AM, Lehman S, Williams G, et al. Identification and importance of brown adipose tissue in adult humans. N Engl J Med 2009;360:1509–1517
4. Ouellet V, Routhier-Labadie A, Bellemare W, et al. Outdoor temperature, age, sex, body mass index, and diabetic status determine the prevalence, mass, and glucose-uptake activity of 18F-FDG-detected BAT in humans. J Clin Endocrinol Metab 2011;96:192–199
5. Peirce V, Carobbio S, Vidal-Puig A. The different shades of fat. Nature 2014;510:76–83
6. Yoneshiro T, Saito M. Activation and recruitment of brown adipose tissue as anti-obesity regimens in humans. Ann Med. 5 June 2014