Health Notes: How much of a role does the brain play in obesity?

This is another in an occasional series of SNEWS® Health Notes reports that will take a look at recent research studies or reports about health, fitness, physical activity and wellness. We’ll focus on news you can use and present results in plain English, without all the techno-garble that can make many research studies seem overwhelming to read, let alone understand and explain to somebody else. Let us know what you think, what you would like to see, and how you’d like to see it!

We all know that an imbalance in energy output and energy intake is a major factor behind obesity. But scientists have begun to explore other links and causes. A multi-national group of scientists has just announced that it has discovered common variations at seven new sites in the human genome that could influence obesity.

The team, based in Iceland, analyzed genomes (the genetic material of an organism) from more than 30,000 people from Iceland, the Netherlands, and the United States, and confirmed the findings in data from more than 40,000 individuals from Denmark.

“One of the most notable aspects of these discoveries is that most of these new risk factors are near genes that regulate processes in the brain. This suggests that as we work to develop better means of combating obesity we need to focus on the regulation of appetite at least as much as on the metabolic factors of how the body uses and stores energy,” said Kari Stefansson, CEO of the bio-pharmaceutical company deCODE and senior author on the paper.

Despite deCODE’s interest as a pharmaceutical company in the development of drugs, it goes on to report that obesity is a growing concern in industrial nations and that it results from consuming more calories that are used. Its report notes that a third of the population of the United States is now classified as obese, and the World Health Organization estimates that around the world as many as 400 million people are obese. It notes that behavioral factors such as diet, eating habits and lack of exercise play a major role. But deCODE goes on to say that “these interact with genetic factors that influence the regulation of appetite as well as how the body uses energy and stores it as fat. The aim of the study published today was to identify more of these genetic factors as a means of better understanding the biological processes that contribute to obesity.”

For insight, the company deCODE (www.decode.is) is also behind the test growing in popularity that allows someone to submit a swab from inside their cheek and have their DNA analyzed to show what diseases they may be at risk for. This process (www.decodeme.com) and its validity and viability have been questioned by some scientists.

So what? Eating right and being physically active remain pivotal to “curing” obesity, but there could be some genetic links that mean some are at risk more than others, just as some are more at risk for certain cancers. Nevertheless, we certainly don’t want drug companies who see dollar signs to make a pill the answer when most people just need to eat less and get more active.



For the scientifically minded: The paper, titled “Genome-wide association yields new sequence variants at seven loci that associate with measures of obesity,” was published Dec. 15 in the online edition of Nature Genetics (www.nature.com/ng), and will appear in an upcoming print edition of the journal.