High-fat and high-sugar diet bad for brain

Overeating can confuse the brain’s immune system, upsetting the functions of normally inactive parts of its hypothalamus region, according to researchers at the University of Wisconsin-Madison.

According to the researchers, too many calories seem to activate a normally dormant protein pathway in the hypothalamus. This gland located in the mid-part of the brain regulates appetite and feeding behavior, and therefore plays a key role in body processes such as metabolism and the body-weight balance.

Many previous studies have cited obesity as a cause of a low-grade chronic inflammation that occurs all over the body. The inflammation usually appears in diseases associated with obesity, such as heart disease and diabetes. A particular compound, known as IKKbeta/NF-kappaB, has previously been identified as actively involved in the inflammatory responses of the immune system.

The current research found what was not previously known: that the compound was also operating in the central nervous system. The team found high levels of it in the hypothalamus where it was normally inactive.

Working with mice brains, the researchers observed that a high-fat or high-sugar diet made the IKKbeta/NF-kappaB compound in the hypothalamus extremely active.

Once the protein was activated the mice started eating more. It appeared the body did not respond to signals from other hormones: leptin, whose function is to regulate appetite, and insulin, which helps in converting food to energy.

In mice where this pathway was blocked, the animals did not eat compulsively and were able to keep their weight normal.

The activated pathway appeared to induce insulin resistance and to upset the fine balance of hormones involved in weight control and appetite.

This means that even before obesity has become established in the body, excessive calorie consumption activates the pathway. Once switched on, there is a tendency to overeat, further promoting overconsumption and leading to a vicious cycle.

If a way could be found to block the pathway, it could help fight the growing epidemic of obesity and overweight and the related diseases.

Overweight and obesity are fast becoming an enormous public health concern. Among all U.S. adults, one of three is overweight, and another one of three is obese.

The problem of obesity is not limited to the U.S. In 2007, health experts believe there are 1.8 billion people worldwide who are overweight or obese.

Drugs currently available to fight obesity provide only limited success but can cause severe side-effects. Dietary changes and exercise for overweight and obese people can be effective but only for limited periods. Long-term weight control for them is difficult to achieve.

Safety Tip:

* Avoid overeating. It should help prevent becoming overweight by not activating the pathway in your hypothalamus.