‘Brown Fat’ May Help Your Health, Even if You’re Obese
By Dennis Thompson
MONDAY January 11, 2021 (HealthDay News) – A special type of body fat that burns calories appears to help protect against an array of chronic diseases, including heart disease, type 2 diabetes and high blood pressure, according to a new study.
Brown fat generates heat by pulling glucose out of the bloodstream, as opposed to white fat which stores energy, explained lead researcher Dr. Paul Cohen. He is an assistant professor and senior attending physician at Rockefeller University Hospital in New York.
This kind of fabric looks like a godsend. However, it was long believed that brown fat has little impact on human health, as your stores of brown fat decline with age.
But research now shows that adults who have active brown fatty tissue in their bodies are much less likely than their peers to suffer from various chronic diseases.
In addition, this protective effect holds even if the person is overweight, researchers recently reported in the journal. Nature medicine.
“When we grouped our subjects based on their body mass index, we saw that even obese people with brown fat show protection against these conditions,” Cohen said.
“For example, it’s well known that type 2 diabetes is more common in overweight and obese people, but what we have seen is that even obese people who have brown fat have a significantly lower with type 2 diabetes than obese people without brown fat, ”he continued.
Brown fat is believed to be an evolutionary response to cold weather, helping to generate heat to maintain the body’s core temperature, experts say.
“Babies can’t shiver, and so when they’re cold they activate brown fat and stay warm that way,” said Ruth Loos, program director for Obesity Genetics and Related Metabolic Traits. Charles R. Bronfman Institute for Personalized Medicine. Icahn School of Medicine at Mount Sinai, New York.
“For a long time it was believed to be present in babies, and as we get older it was believed to go away,” Loos said. “Now, with better measurement methods, we now know that it doesn’t go away completely in adults. Some people have a measurable amount of brown fat, which we didn’t know about before.
Cohen said that studies done a decade ago “have generated a lot of excitement because they have shown that adult humans have brown fat that can be stimulated by exposure to cold and is functional. , which means it absorbs glucose from the bloodstream. ”
The brown fat is found in a layer of fat under the skin, usually in an area extending from the base of the head and down the shoulders and then along the spine, said Dr Aaron Cypess, chief by Acting in the Translational Physiology Section of Diabetes, Endocrinology and Obesity at the US National Institute of Diabetes and Digestive and Kidney Diseases.
Researchers can detect active brown fat stores using PET scans that are normally used to diagnose and track cancer by looking for tissue that burns high levels of glucose.
Cohen and his team contacted Memorial Sloan Kettering Cancer Center, obtaining more than 130,000 PETs from more than 52,000 patients. They then looked at those scans for brown fat deposits.
Nearly 10% of the patients carried active brown fat, Cohen said. He added that this was likely an underestimate as patients undergoing the scans were asked to avoid exposure to cold, exercise and caffeine, all of which increase brown fat activity.
Researchers checked previous results on brown fat – that women are more likely to wear it than men, that the amount of brown fat decreases with age and weight gain, and that active brown fat is more likely to be found in analyzes performed in cold or hot weather.
But when the research team compared brown fat levels to patients’ medical histories, they found new associations between brown fat tissue and better overall health in people, regardless of their weight.
For example, people with active brown fat have improved levels of cholesterol and blood sugar. They were also less likely to have high cholesterol, coronary heart disease, congestive heart failure, high blood pressure, and type 2 diabetes.
“Some of these associations have never been documented before,” Cohen said, although the study did not definitively prove that brown fat leads to a lower risk of disease.
It is not yet clear why this link might exist, Cypess said.
“Is it through the simple process of burning glucose and fat to keep you warm, or does brown fat also act as an endocrine organ that releases hormones into the blood and leads to these benefits?” Cypess said.
It doesn’t take extreme cold to activate brown fat, Cohen noted – even a few hours in a 60-degree Fahrenheit room is enough.
This temperature “is cool but certainly not freezing,” Cohen said. “I think it’s fascinating from a public health standpoint that just lowering our thermostats a few degrees can have health benefits.”
Researchers and pharmaceutical companies are also looking for drugs that could activate brown fat and promote these benefits, Cohen said.
However, experts all agreed that too little was known about brown fat for anyone to try to lose weight or gain health benefits from walking in cool rooms or the freezing cold outdoors. .
“If you eat less during a meal, you might be better off losing weight than trying to increase your brown fat,” Cypess said. “I’ll always tell you that the two things you need to do are eat a healthy diet and exercise, and hopefully you can incorporate brown fat activity into this plan.”
The US National Institutes of Health has more on brown fat.
SOURCES: Paul Cohen, MD, PhD, assistant professor and senior attending physician, Rockefeller University Hospital, New York City; Ruth Loos, PhD, director, Program in Obesity Genetics and Related Metabolic Traits, Charles R. Bronfman Institute for Personalized Medicine, Icahn School of Medicine in Mount Sinai, New York City; Aaron Cypess, MD, PhD, Acting Chief, Translational Physiology Section, Diabetes, Endocrinology, and Obesity Branch, US National Institute of Diabetes, Digestive and Kidney Diseases; Nature medicine, January 4, 2021, online
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