Not all body fat is the same. Body fat is not inherently evil. Not only are there differences in histological patterns that differentiate fat, but different fat appears to function in different ways. We can often lose sight of these facts in our ever pressing "get skinny or die trying" pursuit of health.
In a recently published study in the journal Nature Medicine, researchers compared individuals with brown adipose tissue (BAT) or brown fat vs individuals without brown fat as identified through PET scanners. Brown fat has long been associated with certain health promoting qualities, but most research has been done on lab animals and newborn babies. It has been observed that, as contrasted with white fat, which stores sources of energy, brown fat is more metabolically active and thus burns more energy. In general, it has been observed that individuals with higher brown fat enjoy better health. But the specifics of this observation have remained vague.
In the present study, however, some clarity has been brought forth. In comparing scans and health records for over 50,000 participants, it was revealed that those individuals with detectible brown fat were significantly less likely to suffer from cardiac and metabolic conditions ranging from coronary artery disease to type 2 diabetes. For example, it was demonstrated that only 4.6% of individuals with brown fat had type 2 diabetes vs 9.5% prevalence in non-brown fat individuals. 18.9% of brown fat individuals had elevated cholesterol vs 22.2% in non-brown fat individuals. Also, brown fat presence appeared to be protective for other chronic conditions including: congestive heart failure, hypertension, and coronary artery disease.
Interestingly, brown fat appeared to be protective even when present in obese individuals. In fact, obese individuals with a presence of brown fat carried no different risk from common heart and metabolic disorders as compared to the non-obese population.
While this evidence is only from a correlation perspective, it represents a potential for understanding a significant health benefit from brown fat. This also opens new doors for a therapeutic avenue. The obvious question arises: "if brown fat is good, how do we get more?" Based on current understanding, the following actions are demonstrated to increase brown fat:
Cold exposure- Exposure to cool and even cold temperatures may help recruit more brown fat cells. Some research has suggested that just two hours of exposure each day to temperatures around 66˚F (19˚C) may be enough to turn white fat to brown.
Consider taking a cold shower or ice bath. Turning the thermostat down a few degrees in your home or going outside in cold weather are other ways to cool your body and possibly create more brown fat.
Exercise- Research on mice suggests that a protein called irisin may help transform white fat to brown. Humans also produce this protein. Researchers uncovered that people who are sedentary produce far less irisin compared to those who exercise often. Specifically, levels are increased when people do more intense aerobic interval training.
Current physical activity guidelines for adults include doing one of the following every week:
150 minutes of moderate activity, such as walking or playing tennis
75 minutes of vigorous activity, such as jogging or swimming laps
There’s not enough research to know for sure if exercise creates more brown fat. But exercise has so many health benefits that you should do it regardless
Increased caloric intake- Researchers overfed mice and found that those with more brown fat burn more calories. They stayed leaner and healthier this way. They were also protected from obesity and other metabolic diseases. The most reliable recommendation to draw from this is not to overfeed, but rather to not dramatically reduce calories in order to lose weight and stay healthy. Keep a basal level of energy intake and maintain adequate activity levels.