Quantum: Obesity fueled by reward-behavior gene

A QUANTUM OF SCIENCE

Obesity risk factor gene found to act in an unlikely place: our minds

Researchers analyzed the DNA of over 30,000 humans in 8 different studies and found three separate localed regions (or "loci") in their DNA where many of those studied had very similar subtle differences ("single-nucleotide polymorphisms"). The presence and number of copies of these genes with subtle differences correlated almost precisely with measurements of waist circumference, body mass index, and obesity. Two of these genes were known from other studies, but the newest gene, NRXN3, has a surprising role in the body. Instead of regulating the growth and proliferation of fat cells, or guiding the metabolic rate up or down, it acts on the central nervous system to modulate so-called "reward behavior," in which the brain receives positive feedback stimulation when a particular behavior is performed.

While these results are enlightening, they are not a genetic test for obesity risk nor even necessarily an indication that science is racing to "cure" obesity. But by understanding the underlying factors better, new strategies to address the expanding epidemic of obesity may be hastened. Moreover, NRXN3, is also associated with susceptibility to addiction and further research may reveal additional therapies to help affected individuals overcome that as well. What is more frightening is the knowledge of how similar those two scourges truly are - obesity as an addiction to food is a chilling idea.

For more information:

NRXN3 Is a Novel Locus for Waist Circumference: A Genome-Wide Association Study from the CHARGE Consortium (Nancy L. Heard-Costa et al)

© A Quantum of Science / P. Smalley
Reproduction with attribution is appreciation