Harmful protein holds key to fighting obesity

Lu Zhihao, known as Chinas fattest child, eats BBQ food in Foshan city, southeast Chinas Guangdong province, 29 March 2011. PHOTO | FILE

What you need to know:

  • The researchers created genetically modified mice which produced excessive levels of Id1 in their fat cells. They fed the mice a high-fat diet as well as a regular diet and fed a control group of mice the same diets.
  • The mice with too much Id1 gained much more weight, not just on the high-fat diet, but also on the regular diet, than the control mice.

Protein is a vital part of a balanced diet, critical for cell structure and function, but high levels of a particular protein called Id1 may increase the risk of obesity and diabetes, new research has found.

Previous research had linked this protein to the risk of developing prostate cancer. The presence of Id1 in the body, interferes with the functioning of brown and beige fat, two of three types of fat (including white) found in the body.

White fat, which is considered unhealthy, and which is usually found around the waist, stores energy in the form of triglycerides, a type of fat in the blood which, in abnormally high amounts, triggers heart disease and diabetes.

Brown fat, on the other hand, is considered healthy and burns energy to create heat for the body when it is exposed to cold temperatures in a process called thermogenesis.

UNUSED FOOD

The presence of Id1 interferes with the ability of unhealthy white fat to be converted into beige fat, which burns energy just like brown fat. Brown and beige fat also have more mitochondria than white fat, which helps them turn food into energy and contributes to body leanness.

The research led by Dr Satya Ande, a molecular biologist at the Georgia Cancer Center and Medical College of Georgia at Augusta University and published in the journal Diabetes, showed that by suppressing Id1 and actively promoting energy burning and conversion of white fat to beige, people can be saved from the risk of diabetes and heart disease.

The researchers created genetically modified mice which produced excessive levels of Id1 in their fat cells. They fed the mice a high-fat diet as well as a regular diet and fed a control group of mice the same diets. The mice with too much Id1 gained much more weight, not just on the high-fat diet, but also on the regular diet, than the control mice.

High levels of Id1 bind to brown adipose tissue, suppressing its fat-burning action. Removing the Id1 gene increased the ability of white fat to turn into beige when exposed to cold. Moreover, the researchers found that removing the Id1 gene, did not seem to suggest that it was needed for normal functioning in mice.

Obesity occurs when people eat more food than they need or fail to use it up when expending energy.

The unused food is converted into triglycerides (white fat) which the body can turn to for energy when a person has not eaten enough. However, too much of white fat in the blood exposes one to the risk of heart disease and diabetes.

To deal with this regular exercise and exposure to cold temperatures can help, by increasing the levels of brown fat and beige fat in the body. This is especially important as one grows older because the body finds it harder to make brown fat with age.