You could easily be forgiven if you thought that all fats are the same, or that body fat is just that, body fat? In fact, there are three types of fat …. the technical name is adipose tissue, white, brown, and beige. White adipose tissue (WAT), is an energy-storing organ that enabled survival for longer periods between meals in the hunter-gatherer era. White fat is widely distributed throughout the body and represents the vast majority of the fat. Excess WAT is a primary cause of inflammation which promotes cardiovascular disease, diabetes, and several cancers.
Brown and beige adipose tissue are very different lumps of lard, which burn rather than store energy. The mitochondria (cellular energy plants) in BAT/beige fat are unharnessed from energy production and generate heat to maintain body temperature through what is called non-shivering thermogenesis during cold exposure.
This uncoupling of energy production to release heat is like a car in neutral with the accelerator pedal to the floor, you can burn a lot of fuel, and the fuel represents our fat. If you increase BAT activity, you can significantly decrease excess body fat. Decreasing fat lowers your risk for diabetes, cardiovascular disease, and several cancers. The bonus of course is you also lose that belly. It’s all good.
BAT was thought to develop during fetal development, peak at birth, and decline after the first year of life when infants develop the ability to shiver. In 2009, researchers using PET scans (positron emission tomography, an imaging technique that reveals areas with high metabolic activity) to diagnose cancer, discovered BAT in adults. BAT, like cancer cells, has a very high metabolic rate.
This finding ignited a flurry of research targeting BAT’s capacity to increase energy expenditure and thereby lose weight. Here is a brief review of what we know about activating BAT and converting WAT to beige fat.
*Picture: UC Berkeley, University of California
Cold Exposure
This harnesses the primary function of BAT. Some researchers have theorised that constant control of environmental temperature has contributed to the obesity epidemic. From an evolutionary perspective, we evolved at the equator where daytime temperatures are high and night-time temperatures low. Such daily swings would consume significant amounts of energy to maintain body temperature. This is no no longer the case for most of us.
Numerous cooling techniques have been shown not only to activate BAT but stimulate new BAT production or “browning” of WAT. Japanese researchers exposed healthy adults, with low or undetectable BAT, to an air temperature of 19 degrees Centigrade (66.2 degrees Fahrenheit) for two hours. This relatively brief exposure to cool but not cold temperatures significantly increased BAT activity and raised cold-induced thermogenesis by 167%.
Research has also demonstrated that sleeping in a 19 degree C room for 1 month increased BAT volume and activity compared to 1 month of sleeping in 24 degrees C.
Because water can remove heat more than 20 times faster than air, minutes of cold-water immersion is sufficient to activate BAT. In fact, ending a shower with as little as two minutes of cold works. Start with 15-second exposures and build up to minutes. You will be surprised how quickly the body acclimates.
Dietary Factors
Capsaicin and the Capsinoids
One of the most studied food ingredients linked to BAT activation is capsaicin and the capsinoids. Capsaicin is the major pungent component of hot red chillies. Capsinoids have the same chemical structure as capsaicin and provide the active ingredients in the non-pungent variety of red chilli.
Yoneshiro et al., the Japanese group cited above, examined the effect of a single 9mg dose of capsinoids on BAT. They observed a 3-fold increase in energy expenditure. In addition, daily ingestion of capsinoids for 6 weeks increased the cold-induced energy expenditure.
The research group made a video that illustrates their findings (https://www.youtube.com/watch?v=BnmhmH7AQCs).
Berberine
Berberine, a natural compound derived from the medicinal plant rhizoma Coptidis, is widely used as an anti-diarrhea drug. Researchers noted its capacity to attenuate weight gain. Further investigation revealed positive effects on diabetes and elevated blood lipids. Wu et al. recently demonstrated how berberine activates BAT, increases BAT mass and thereby increases energy expenditure.
Alpha-ketoglutarate (AKG)
AKG is an important biological molecule involved in multiple metabolic pathways.
Resistance exercise has been shown to increase AKG levels which in turn promote activation of BAT and the burning of WAT. AKG also increases blood levels of insulin, growth hormone, and insulin-like growth factor-1, hormones associated with the positive effects of exercise.
In addition, AKG inhibits muscle breakdown, stimulates protein synthesis for muscle growth, and increases collagen synthesis. Recent research has demonstrated its capacity to extend healthspan and lifespan in mice and prevent diet-induced obesity.
The Old Fashioned Way
Any article on fat metabolism would be incomplete without mentioning recent findings on an old practice.
Research has shown that exercise does more than burn calories. Working a muscle releases irisin, a chemical messenger associated with many of the benefits of exercise. Irisin promotes the browning of WAT and thereby increases metabolic rate.
Visit our blog for more articles and recipes.
Let’s get social! Find us on Facebook, Instagram, LinkedIn and Twitter!
Kumud Gandhi is a Nutritional Food Scientist bestselling Author, Broadcaster, and Keynote Speaker on the subject of nutritional health for productivity & performance in the workplace. In 2010 Kumud founded ‘The Cooking Academy’ a cookery school that focusses on cooking for nutritional health and wellbeing. Kumud regularly presents to international audiences on a variety of topics such as ‘Eating for Immunity and a Lifetime of Wellness’. She is an expert in the field of Wellness in the Workplace and works with organizations to create transformational change in employee health & well-being through nutrition and health coaching.
Comments