A large new study has provided strong evidence that people with brown fat in their bodies are less likely to suffer from a variety of health conditions.
“For the first time, it reveals a link with a lower risk for certain conditions,” said one of the researchers, Paul Cohen, a doctor at Rockefeller University Hospital.
“These findings make us more confident about the potential of targeting brown fat for therapeutic benefit.”
Brown fat or brown adipose tissue (BAT) occurs especially in mammals and newborns in hibernation. BAT helps mammals regulate temperature – when we are really cold, the large amounts of mitochondria found in this type of adipose tissue burn energy and produce heat. In fact, the iron-rich mitochondria give brown fat its distinctive color.
Only in 2009 did scientists discover that adults also have brown fat in their bodies, usually around the neck and shoulders.
There have been many mouse studies investigating the benefit of brown fat, but in humans the research has been darker until recently. Having brown fat can improve someone’s metabolism and may even help them to lose weight (although it may not be that simple).
“The natural question everyone has is, ‘What can I do to get more brown fat?'” Cohen says.
“We do not yet have a good answer to that, but it will be an exciting space for scientists to investigate in the coming years.”
If we look at a large collection of 52,487 participants undergoing PET / CT scans to evaluate cancer, the team found evidence of brown fat in just under 10 percent of cases (5,070 people).
The researchers think this may be an underestimation due to the circumstances of the participants – they were told to avoid exposure to cold, exercise and caffeine before the scans, all of which are related to brown fat activity.
About 4.6 percent of those with brown fat also have type 2 diabetes, while the figure was 9.5 percent in the ‘no brown fat’ group. A similar result was seen in abnormal cholesterol results – 18.9 percent of people with brown fat had abnormal cholesterol, compared to 22.2 percent of people who did not have brown fat.
Hypertension, congestive heart failure, and coronary heart disease also showed small positive differences in the brown fat versus no brown fat groups.
“These findings are supported by improved values of lipoproteins in blood glucose, triglycerides and high density,” the team wrote in their new article.
Although the numbers here are exciting, there is still no evidence that brown fat makes you immune to any of these conditions, but there is a link to a reduced risk that is worth investigating further.
What was really interesting was that brown fat was particularly protective in those who were obese. Those with obese patients who had brown fat had the same metabolic and heart diseases as non-obese people.
“They almost seem to be protected from the harmful effects of white fat,” Cohen says.
“Collectively, our findings highlight a potential role for BAT in promoting cardiometabolic health,” the researchers note in their paper.
It is important to note that the data that the researchers worked with came from cancer evaluations at the Memorial Sloan Kettering Cancer Center, which means that it is not an example of the general population.
Nevertheless, the study provided a fascinating new look at the role of brown fat in the human body, and will hopefully lead to even more discoveries in the future.
“We are considering the possibility that brown adipose tissue does more than consume glucose and burn calories, and perhaps also participate in hormonal signaling to other organs,” says Cohen.
The research was published in Physical Medicine.