A New Diet Plan? Brown Fat and Cold Temperatures

As babies, we are all born with brown fat, a fat that actually produces heat and consumes calories since we aren’t able to shiver and warm our bodies as infants. Previously it had been thought that we outgrew brown fat once our bodies were able to shiver and produce heat. There is new evidence that suggests we actually still have brown fat as adults. Brown fat, along with cold temperatures which put the fat to work producing heat and burning calories, may be a new diet avenue for researchers and doctors to explore.

When you hear the words “brown fat,” it doesn’t mean the fat under the skin that has been tanned from the sun, even though brown fat actually does look brown. Its brown color is from its component of mitochondria, which contains iron. Brown fat isn’t noticed by the naked eye, but rather through PET (positron emission tomography) scans; which is one way that doctors and researchers actually realized brown fat does still exist in adults and doesn’t disappear as babies.

Three newly released studies were published in the April 9th issue of the New England Journal of Medicine detailing research that has determined that brown fat still exists in adults and can actually burn calories when activated through cold temperatures.

Dr. Aaron Cypress, lead author of one of the studies with Joslin Diabetes Center in Boston said, “The incredible excitement about this is that we have an entirely new way to try to go after obesity.” Dr. Cypress and his colleagues evaluated over 1,900 patients who had undergone PET scans for different reasons and their study showed 7.5 percent of the women had brown fat areas bigger than 4 millimeters and 3.1 percent of the men had brown fat similar in size. They discovered thinner patients had more brown fat than overweight patients. Patients who were taking beta-blockers or older were less likely to have active brown fat. Dr. Cypress said, “The general public and most scientists didn’t know this existed,” and he said, “We say it’s there and could be used as a treatment for obesity and diabetes.”

One of the other studies published recently was performed by Dr. Sven Enerbäck at the University of Göteborg in Sweden and his team. It also illustrated the presence of brown fat in adults through research involving five patients. His team discovered a sizable amount of brown fat on patient’s front and back of their necks, through modern medical imaging. The team verified the presence of brown fat through genetic analysis. Once they had found the presence of brown fat, they attempted to determine the affects of the brown fat when a patient was exposed to colder temperature, thought to trigger activity in the fat. They placed a patient’s foot into an ice bath while they were undergoing a PET scan, with the temperature in the room between 63° F and 66° F, for five minute intervals over a two hour period. The team noticed an increased activity in brown fat, with the amount of glucose the patient’s brown fat consumed increasing by a factor of 15.

Another study released in the Journal was performed by Dutch researchers from the Maastricht University Medical Center in Netherlands. Their study evaluated the effects of temperature on brown fat in 24 healthy men through PET scans and CT (computed tomography) scans. The volunteer’s scans showed no presence of brown fat activity when sitting in a room at 72° F for two hours, but when the temperature in the room was dropped to around 62°, 23 of the men showed brown fat activity. The leaner men with BMI’s less than 25 showed more brown fat and it was more active than those men who were overweight or obese.

With the newly released research, we may have new reason to look into the presence of brown fat that was once thought to only exist in babies and rodents. Brown fat seems to have the purpose of regulating body temperature, and to do so, it burns high quantities of sugar and releases the energy as heat. With the new evidence of brown fat, and the fact that it does seem to burn calories once the fat is activated, scientist and researchers may have new reasons for discovering ways to trigger brown fat activity. Hopefully, leading to new ways of increasing weight loss and even controlling obesity and other health problems caused from excessive weight.