07.18.13

Do These Genes Make Me Look Fat?

A new study zeroes in on a bit of a DNA that leads to ‘obesity-prone behaviors’ if it gets out of whack. We’re all saved, right?! Not so fast, writes Kent Sepkowitz.

Las Vegas has long been the philosophic capital of U.S. commerce, a physical (if hallucinator) reminder that luck does indeed exist, and, with just enough of it, people like me can get whatever they want.

The same guiding principle of business, unfortunately, is beginning to take root in science as well—most especially in the world of genetics. Since decoding of the human genome was begun in the Reagan years, all 20,000 to 25,000 human genes have been translated to their basic chemical sequences. With this accomplishment, the race has been on to find the big one, the one key gene that magically will make the short tall, the dull sharp or the fat thin. In Vegas parlance: the jackpot.

This week’s entry comes to us from the venerable scientific publication the Journal of Clinical Investigation. In it, a group of European investigators examined the relationship between FTO, a protein associated with fat mass, and obesity. Previous work had shown that persons with variations in the FTO gene were more likely to be obese, but the current researchers wanted to get a bit more specific, so they observed behavioral differences in people with normal versus abnormal FTO genes. For example, they saw differences in the post-meal sense of satiety, in levels of certain hormones that regulate satiety and hunger, and in other “obesity-prone behaviors” between those with and without the aberrant FTO gene—the first evidence of physiologic changes caused by the gene variant. Furthermore, they and others have found that the variant was present in large proportions of patient groups studied, from Roma/Gypsies to skinny Frenchmen.

This work (along with the 385 other articles on the FTO gene and obesity) makes for a truly exciting scientific exploration.

There’s a problem, of course, but it’s not that the scientists are doing shoddy work. Rather, it is the very fineness of the work and its implications for the obesity epidemic—the study leads down an infuriating rabbit hole. The “obesity gene” has been proclaimed, the world says, and the task now seems to be to simply change out the damn gene, like changing a light bulb maybe. Perhaps the world of home improvement will meet the genetics movement: Gene Depot, your store for genetic parts. Simply buy the good gene and take out the bad gene, then put the good gene where the bad gene was. And then you won’t be obese anymore. Just check here to acknowledge you have read the instructions and agree.

There is just a wee small problem with this happy talk: it’s total nonsense. As I have previously written, it ain’t that easy, nor will it be. Ever. Genes are not simple off-the-shelf parts with one expression. There is no obesity gene—rather, there is a gene that is involved in many ongoing chemical reactions throughout the body, one of which appears related to the regulation of a hormone that makes people feel hungry (or feel full). It does countless other things, though who knows what they are exactly. Perhaps the gene might stabilize a membrane in this set of cells or help potassium diffuse a bit more rapidly across a gradient in another particular milieu.

Little Timmy, there will never be a Gene Depot.

Genes don’t have job descriptions. You can’t just swap them out; you might be enticed to try, but likely would find yourself tugging at a thread that, once tugged too much, would lead to a total unraveling. Little Timmy, there will never be a Gene Depot.

The problem is that there is and always will be a Las Vegas, a place where anyone with a dollar and a dream can make over the world. And that narrative—the lucky snake eyes at the table or the oil gusher in the land Granny willed you or the Rembrandt that was underneath that awful old painting you bought for $5—will not go away. We have an insatiable appetite for it, as it turns out. Call it an irremediable obesity-prone behavior.