A dose of the cold could help weight loss and reduce heart disease
Published 17/02/2011 | 11:30
Turning the thermostat down could help obese people lose weight and reduce the risk of heart disease, new research has suggested.
Scientists have found that exposure to the cold can cause a little known type of fat tissue, called brown adipose tissue, to clear harmful fat molecules from the blood stream.
Cold causes the brown fat to burn off these high-calorie molecules, turning them into heat to keep the body warm.
Excessive levels of these high-calorie fat molecules, or triglyceride-rich lipoproteins as they are known, from food can cause the arteries to harden and lead to cardiovascular disease.
They also cause the build up of unhealthy white fat deposits around the body, which leads to obesity.
Researchers at the University Medical Centre Hamburg-Eppendorf, who conducted the research, found that keeping mice at temperatures of around 39.2F (4C) increased the ability of the animal's brown fat to burn off these molecules and reduced levels of body fat.
They claim that increasing the activity of brown fat tissue with exposure to the cold could help to reduce the impact of high fat diets in humans while also help obese patients burn off excess body fat.
Dr Alexander Bartelt, a molecular biologist who led the study, said: "Brown fat acts as sink for blood lipids, especially for high-caloric triglyceride-rich lipoproteins derived from liver and dietary fat.
"If one is able to stimulate brown fat development in humans by pharmacological or biological approaches, elevated blood lipids and obesity are at the top of the list of diseases that can be cured using brown fat."
Brown fat is one form of two types of fat tissue and is found in high amounts in new born babies and hibernating mammals as it helps to generate extra heat to keep their bodies warm while they are not moving.
Unlike white fat, which acts as a store for high energy fat molecules, brown fat burns off these high energy molecules to produce heat.
Adult humans were not thought to have any brown fat as their body heat is mainly generated as a result of muscle movement, but it has recently been discovered that adult humans also have some stores of brown fat in their upper chest and neck.
Recent findings have also suggested that it is possible to increase these deposits of brown fat and that white fat may even convert to brown fat when exposed to extended periods of cold conditions.
Some experts have speculated that modern western lifestyles with central heated houses has resulted in decreased brown fat activity in many adults.
A recent study by researchers at University College London suggested there is a link between reduced exposure to seasonal cold and increases in obesity in the UK and US.
Dr Bartelt and his colleagues, whose research is published in the scientific journal Nature Medicine, now believe that regularly exposing human patients to cold conditions could help create more brown fat, allowing their bodies to burn off excess body fat deposits and reduce their risk of heart disease.