Overweight and obesity How brown fat turns into harmful white fat

Important factor discovered in the emergence of obesity-associated inflammation

A few months ago, a study was published that showed that people with a significantly higher proportion of brown fat, despite higher food intake do not get overweight. As a research team has now found, this fat also plays a key role in the development of obesity-associated inflammation.

Brown fat helps with weight loss

Scientists from the University of North Carolina and Columbia University (both in the US) reported last year on a new fat-way patch to help lose weight by converting white fat, which normally stores energy, into brown fat. which burns the energy. Also designed by researchers from Singapore medicine plaster, which managed to reduce the belly fat by more than 30 percent, based on this effect. Austrian researchers are now reporting the consequences of turning brown into white adipose tissue.

Strong obesity is associated with inflammatory reactions in adipose tissue. These arise to a significant extent because brown adipose tissue is converted to white. That's what researchers have discovered. (Image: andriano_cz / fotolia.com)

For therapies against obesity or diabetes of great interest

Brown adipose tissue acts in the cold as a heating element whose activity is favorable for the energy balance, according to a statement of the Technical University of Munich (TUM).

As humans grow older, this metabolic activity of brown fat decreases. In addition, it is less active in diabetics or obese. That's why scientists are researching the factors that keep the brown fat active.

Because it has the ability to burn energy from carbohydrates and fat, it is of great interest for therapies for obesity or diabetes.

Now in the journal "Journal of Lipid Research" the results of a study have been published, which show what happens when brown becomes white fat.

Inflammation in the fatty tissue

Obesity (adiposity) causes inflammatory reactions in human adipose tissue.

These inflammations arise to a substantial extent because brown adipose tissue is converted to white. This is what scientists from the University of Graz discovered.

As it says in a statement from the university, the work extends the knowledge about the complex interactions as a prerequisite for new therapeutic approaches.

At least two different types of fatty tissue

Humans and mammals basically have at least two different types of adipose tissue: white and brown.

The former stores fat - preferably in the well-known pads on the abdomen and thighs. If the body needs energy, it can use these depots.

Brown adipose tissue, on the other hand, is essential for heat production. That's why babies and hibernating animals have plenty of it.

But adult humans also have smaller accumulations of brown adipose tissue. The role it plays in the context of obesity-associated inflammation has now been demonstrated for the first time in a mouse model.

Process could also play a role in diabetes and cardiovascular disease

"In obese individuals, in addition to the known changes in the white, there are also fundamental changes in the brown adipose tissue," explains Petra Kotzbeck, first author of the aforementioned publication.

"The brown fat cells, which actually have many small lipid droplets, are similar in appearance to the white fat cells and increase in size," said the molecular biologist, who researched at the University of Graz in the context of her dissertation and is now working at the Medical University of Graz.

"When the storage capacity of these whiteened fat cells is exceeded, they die off and trigger inflammatory reactions that are much stronger than those in the classic white adipose tissue."

According to the researchers, their work has shown for the first time that the browning of brown adipose tissue can be seen among other things with obesity and can contribute significantly to the typical inflammations.

"Our new findings suggest that this process could also play a role in diabetes and cardiovascular diseases," says Kotzbeck. (Ad)