Ever get the winter chills and hate living in the cold? Have you ever wondered why you get more chilled as you get older? For those of you who have, there's hope.
Traditionally, brown fat was thought to be the body’s main thermostat that insulated and generated heat to keep the body warm.
“Our findings demonstrate for the first time that muscle, which accounts for 40 per cent of body weight in humans, can generate heat independent of shivering,” says Muthu Periasamy of Ohio State University in Columbus.
Through experiments on mice that had their usual thermostat – brown fat – surgically removed, Periasamy and his colleagues proved that a protein called sarcolipin helps muscle cells keep the body warm by burning energy, almost like an idling motor car, even if the muscles do not contract.
All of the mice had their brown fat removed, but some of them had been genetically engineered to lack sarcolipin too. These rodents could not survive when held at 4 °C, and died of hypothermia within 10 hours. By contrast, mice that could make sarcolipin were able to survive the chilly temperatures and maintained their core body temperature – despite having no brown fat.
Chilled with age
Studies have shown that as we age, we tend to lose that vital lean mass, up to 8% each decade over 40, and accelerates as we age. This includes our lean muscle that burns those calories. Our metabolism slows, cooling our body's furnace and fat burning potential. Our body decreases production of sarcolipin that helps fuel the heat generation in our body.
As our metabolism slows, weight and fat percent can start to increase. Often one goes on starvation diets to lose that extra weight, but this can have negative consequences. Starvation diets consume vital lean muscle over time needed to burn calories. Your body has less energy that fuels your body's furnace to stay warm.
Another interesting correlation found in the study is that those mice who are unable to generate the sarcolipin ended up being more susceptible to obesity. “The most interesting finding is that mice unable to make sarcolipin are more susceptible to obesity,” says Andy Whittle of the University of Cambridge, who is testing spicy dietary treatments to ramp up the fat-burning activity of brown fat. “The research demonstrates that muscle is an important component even in mice, which have comparatively more brown fat than humans. In humans, burning fat in muscle is likely to be even more important for proper energy balance.
How can I overcome all this?
The common misconception that people have is that if they walk or do other forms of aerobic exercise, they'll be able to increase their energy. However, this only burns calories while performing the exercise, but does not build muscle that burns energy.
The best way to improve that healthier lean muscle is to incorporate effective strength training. Mayo clinic recommends strength training 2-3 times per week to stay in good shape. Often people think they might bulk up or put on, but it is the only way that you can maintain your healthy lean muscle and strengthen bones.
Don't go it alone. It is important to have a guided program with a fitness professional to personalize your program. Be sure that it includes the right mobility, endurance, and latest strength training technology to make it safe and effective for you. The program should include a comprehensive nutrition program that gives your body the right nourishment and steers clear of fad diets that cause you to lose that vital lean muscle that you need to stay warm.
Journal reference: Nature Medicine, DOI: 10.1038/nm.2897, Newscientest.com