Obesity a Genetic Trait?

A distinctive neural circuitry that controls appetite in some obese individuals may be an innate genetic trait, and may be at least partially responsible for their obesity. A recent study at the University of Southern California, conducted on mice, has shown that the brains of DIO (diet induced obesity) mice often are wired differently than those of normal-weight mice.

The arcuate nucleus of the hypothalamus (ARH), which is the technical labeling of the neural pathways in the brain accounting for appetite, hunger and body-weight control, was studied in both DIO and non DIO mice. What was found was that the ARH of DIO mice had less neural activity than in non DIO mice.

The observation of less neural activity in the ARH for mice with DIO actually happened before many of the mice developed obesity, with the trait often being observed near birth. This suggests that the lowered activity in the ARH may be a genetic trait, giving the mice little control over whether they will develop DIO or not.

There are many implications for this finding. If in fact the conclusions drawn on mice can translate to human beings (a necessary study to be done), there will be a revolution in the way doctors and nutritionists treat obese individuals. It may be possible to start going away from short-term fixes like diets or diet pills, which may temporarily suppress appetite, and start treating and stimulating the appropriate neural pathways in the ARH.

The above study is a starting point for the potentials mentioned, with both the definite human connection to the issue, and the possible treatments for stimulating circuitry in the ARH, unknown. Nonetheless, this study lays the foundations for further research into a very important subject: over 60 million Americans can be labelled as “obese,” and many more are considered at risk. And obesity is a leading contributor to many other conditions, such as heart disease and diabetes. Controlling obesity from a fundamental neural standpoint could potentially have a major positive impact on many conditions.

Source: Defeat Diabetes Foundation: Bouret, Sebastian. Gorski, Judith. et al. Cell Metabolism. “Hypothalamic Neural Projections Are Permanently Disrupted in Diet-Induced Obese Rats.” February 2008.