STI: Fat is good

April 12, 2009

Fat is good

Fat which is brownish and stored around your neck could help you lose weight, studies show

Boston - Fight fat with fat? The newest obesity theory suggests that may one day be possible.

 

Just like cholesterol, there apparently are good and bad types of body fat. Scientists until recently believed this good fat, which spurs the body to burn calories to generate body heat, played an important role in keeping infants warm but which by adulthood was mostly gone or inactive.

 

Now three studies - from researchers in Boston, Finland and the Netherlands - show that some good fat remains in adults, affecting metabolism and potentially helping people shed kilograms.

 

Dr Francesco Celi, an endocrinology and metabolism researcher at the National Institute of Diabetes and Digestive and Kidney Diseases, said the studies show this fat burns large amounts of energy.

 

'So it could be used as a target for a pill that would somehow rev up the fat,' he said.

 

Dr Louis Aronne, former president of the Obesity Society and a weight-control expert at Weill Cornell Medical Center in New York, said the findings are the most conclusive evidence so far of the role of such fat in regulating body temperature and weight.

'I don't want to use the phrase 'exercise-in-a-pill' but it's doing something that is getting rid of calories,' he said, adding that any obesity treatment developed around the fat could be a potential treatment for diabetes as well.

 

The good fat is brownish, while the more predominant bad fat is white or yellow. Brown fat is stored mostly around the neck and under the collarbone. White fat tends to concentrate around the waistline, where it stores excess energy and releases chemicals that control metabolism and the use of insulin.

 

All three research groups documented the presence and activity of brown fat by examining tissue samples from patients and using high-tech imaging that indicated how much sugar, and therefore calories, the fat burned.

 

One group from Joslin Diabetes Center, Harvard Medical School and three hospitals in Boston looked at scans done on about 2,000 patients to diagnose various health problems. The other two groups scanned small numbers of patients, first at room temperature and then a few hours later at about 15 deg C.

 

Here are what the scientists learnt about brown fat:

 

Lean people had far more of it than overweight and obese people, especially among older people.

 

It burns far more calories and generates more body heat when people are in a cooler environment.

 

Women were more likely to have it than men and their deposits were larger and more active.

Pharmaceutical companies have been unable to develop a medicine that helps people safely lose and keep off a significant amount of weight. Dr Aronne said the findings would likely renew interest in the area of brown fat among drugmakers.

 

So how could researchers use these basic findings about good fat to come up with a weight-loss medication?

 

One possibility would be a pill to stimulate a specific protein to release more energy from the fat cells in the form of heat rather than storing it for future energy needs, Dr Aronne and Dr Celi said.

 

Finding a way to increase the amount of brown fat in a person would be another strategy. Researchers at Dana-Farber Cancer Institute in Boston have been injecting certain genes into mice to try to produce brown fat cells instead of white ones.

 

Dr Celi also said researchers could try to make a pill that stimulates nerve endings inside brown fat to make it burn more calories.

 

Or overweight people could simply try turning down the thermostat to see if it makes them burn more energy and lose weight, a strategy that Dr Celi and researchers are testing in a small study that could produce results by the end of the year.

 

Associated Press