A variant of a gene called the fat mass and obesity associated (FTO) gene causes people to gain weight and puts them at risk for obesity. The gene variant is found in nearly half of all people in the U.S. with European ancestry, around one-quarter of U.S. Hispanics, 15 percent of African Americans and 15 percent of Asian Americans. A new study involving 206 healthy elderly subjects from around the U.S. now suggests that this gene variant is also associated with loss of brain tissue. It’s not clear why, but the gene is highly expressed in the brain. Those with the "bad" version of the FTO gene had an average of 8% less tissue in the frontal lobes, and 12% less in the occipital lobes. The brain differences could not be directly attributed to other obesity-related factors (cholesterol levels, hypertension, or the volume of white matter hyperintensities), which didn’t vary between carriers and non-carriers. But if you have this gene variant, your weight is associated with neuron loss, and if you don't, it isn’t. The finding emphasizes the need for those with the gene to fight weight gain (and brain loss) by exercising and eating healthily.
(2010). A commonly carried allele of the obesity-related FTO gene is associated with reduced brain volume in the healthy elderly.
Proceedings of the National Academy of Sciences. 107(18), 8404 - 8409.
Full text is available at http://www.pnas.org/content/107/18/8404.abstract?sid=d95d84c7-f052-4d50-...