Drinking a cup of coffee would be beneficial for brown fat, which greatly contributes to the transformation of calories into energy.
Coffee could fight against obesity. British researchers at the University of Nottingham (London) show that caffeine stimulates brown adipose tissue, which turns dietary calories into energy. Their results were published in the journal Nature.
The main types of adipose tissue present in the human body are brown fat and white fat. The first one allows the body to burn calories by turning them into energy, the second stores calories as fat. “Brown fat works differently from other body fats and produces heat by burning sugar and fats, often in response to cold,” says Professor Michael Symonds, who led the study. The increase of its activity improves the control of blood sugar as well as the optimization of the rate of lipids in the blood and the additional loss of weight in calories”.
Researchers conducted in vivo and in vitro experiments to understand what role caffeine plays in the energy production process. When they exposed adipocytes (the cells that store fat) to caffeine, they found that it boosted their metabolism.
In parallel, they evaluated the amount of UCP1 protein present in brown adipose tissue—this protein is activated during the transformation of dietary calories into energy. Exposure of the cells to caffeine increased the amounts of UCP1 protein, which indicates there has been a transformation of calories into higher energy.
The researchers wanted to confirm these results in humans. Using a thermal imaging technique, they located the brown fat in the participants’ necks and studied the heat variations in the area. When they drank coffee, the temperature increased.
For the researchers, this is a sign of thermogenesis, a creation of heat related to cellular activity, and therefore an impact of caffeine on the manufacture of brown fat. “This is the first human study to show that just taking a cup of coffee can have a direct effect on the functions of brown fat,” says Dr. Symonds. “The potential consequences of our results are rather important. Because obesity is a major concern for public health, the number of diabetes cases is increasing, and brown fat could potentially be part of the solution to combat this.”
If the results are confirmed, caffeine could be used in treatments to combat obesity. The consumption of coffee must however remain measured: it should not exceed 4 cups a day.