Turn down the central heating and you’ll not only reduce the fuel bill, you’ll lose weight. That’s the extraordinary message behind Patrick Rensen’s talk at the upcoming TEDxDelft event.
As a Professor of Endocrinology at Leiden University Medical Center, Rensen studies the role of sugar and fat metabolism in diabetes and heart disease. In particular, Rensen is investigating something called ‘brown fat’ which is different from the all too familiar ‘white fat’ that tends to collect around our middles. “We know that babies are born with brown fat,” says Rensen, “but we thought it disappeared after a few years.”
Recently however it was discovered that adults also have brown fat. It accumulates near the collarbone and heart where there is a lot of blood flow. This discovery got Rensen and his team at Leiden University Medical Center thinking. “We know that brown fat plays a role in temperature regulation in babies,” explains Rensen. “So why would adults need it, given that we wear clothes? At a normal room temperature of about 25˚C – that’s around 77˚F – brown fat does not need to be active. So what’s it there for?” The team decided to find out the therapeutic implications of brown fat.
When volunteers are cooled below this temperature, brown fat is activated, and maximum activation takes place at a temperature at which they shiver. In other words, when the room temperature is low, brown fat burns calories. What is particularly exciting is the discovery that brown fat burns up the sorts of fats that increase the risk of developing heart disease and type 2 diabetes. This means that a cooler room temperature will stimulate brown fat to burn the ‘bad fats’ in our blood stream reducing the risk of obesity, and therefore diabetes and heart disease.
“Activating brown fat to burn 200 kcal per day,” says Rensen, “can translate to about three kilograms of weight loss per year. We are now investigating whether nutritional and pharmacological interventions may be effective as well.”