A large new study has provided strong evidence that people who have brown fat in their body are less likely to have a health condition.
“For the first time, it reveals a link to a lower risk of certain conditions,” says physician Paul Cohen of Rockefeller University Hospital.
“These findings make us more confident about the ability to target brown fat for therapeutic benefit.”
Brown fat or brown fat tissue (BAT) is especially common in hibernating mammals and newborns. BAT helps mammals regulate temperature – when we are really cold, large amounts of mitochondria are found in this type of fat tissue that burns energy and produces heat. In fact, iron-rich mitochondria give brown fat its distinctive color.
It was not until 2009 that scientists discovered that some adult humans have brown fat in their bodies, usually around the neck and shoulders.
Many rats have studied the benefits of brown fat, but this research has been unfavorable in humans until recently. Having brown fat improves a person’s metabolism and can also help in losing weight (although the latter is probably not as simple).
“The natural question that everyone has is, ‘What can I do to get more brown fat?” Says Cohen.
“We don’t have a good answer to this yet, but it will be an exciting place for scientists in the coming years.”
Looking at a large dataset of 52,487 participants under PET / CT scan for cancer evaluation, the team found evidence of brown fat in only 10 percent of cases (5,070 people).
Researchers think this may be a weak condition because the conditions that the participants were in – they were told to avoid exposure to cold before a scan, exercise and take caffeine, all linked to brown fat activity.
Approximately 4.6 percent of people with brown fat had type 2 diabetes, compared to 9.5 percent in that number 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, while 22.2 percent of people did not have brown fat.
Hypertension, heart failure, and coronary artery disease also showed small positive differences in the brown fat versus no brown fat groups.
“These findings were supported by improved blood sugar, triglyceride, and higher density lipoprotein values,” the team writes in its new paper.
While the numbers here are exciting, there is no evidence yet that brown fat makes you immune to any of these conditions – but there is a link to lower risk for further exploration.
However it was really interesting that brown fat was particularly protective in those who were obese. In obese patients who had brown fat, these metabolic and heart conditions were also prevalent like non-obese people.
“It almost looks like they are protected from the harmful effects of white fat,” says Cohen.
“Taken together, our findings highlight a potential role for BAT in promoting cardiometabolic health,” the researchers wrote in their paper.
It is important to note that the researchers came from an evaluation of cancer at Memorial Sloan Kettering Cancer Center, meaning that this sample is not representative of the general population.
Nevertheless, the study has given an attractive new look at the role of brown fat in the human body, and it is expected that more will be discovered in the future.
“We are considering the possibility that brown fat tissue does more than consume glucose and burn calories, and perhaps actually participate in hormonal signaling to other organs,” Cohen says.
The research has been published in Nature medicine.