6 genetic variants variants have been identified as possible contributing factors for obesity. 5 of them are expressed in the brain.
A genetic study of more than 90,000 people has identified six new genetic variants that are associated with increased Body Mass Index (BMI), the most commonly used measure of obesity. Five of the genes are known to be active in the brain, suggesting that many genetic variants implicated in obesity might affect behaviour, rather than the chemical processes of energy or fat metabolism.
Obesity is an increasing problem that results in individual risk to health as well as increasing burdens on health care systems. By identifying genetic variants that affect obesity, researchers hope to understand better the mechanisms regulating energy balance, which will guide the development of new therapies and help to develop improved diagnosis.
These genes reduce the human capacity to exercise free will. People who want to lose weight but find themselves compelled to eat do not have free will over the amount of food they consume.
For example, one of the genes, NEGR1, controls how your brain is wired as it is developing by regulating neuronal growth, Abecasis said.
"In younger children, ages 5-10, we found that with three of (the genes) the children were already heavier at that young age, and with the other three genes, we saw that there was no effect on children," he said. "For those, we only saw an effect in much older individuals. This points to different mechanisms influencing your weight at different ages."
Another example is SH2B1, which was first discovered by U-M researchers studying mice, Abecasis said. Researchers created an obese mouse then returned it to its normal weight by turning on the SH2B1 gene in the brain.
We are going to hear about many more genetic variants that influence behavior every year. The cost of genetic testing has dropped so far that studies search through large amounts of genetic data are becoming cheaper and more feasible to do. Costs of genetic testing and genetic sequencing will continue to plummet and the rate of discovery will continue to rise.
|Share |||Randall Parker, 2008 December 14 10:24 PM Brain Appetite|