Study: Can We Tell Our Genes to Make Us Fat?

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REUTERS/Lucas Jackson

The fight against obesity has engaged many fields of medicine: genetics to predict it; nutrition to prevent it; surgery to manage it; and endocrinology to deal with one of its biggest side effects, diabetes.

Enter Dr. Andrew Feinberg, an epigeneticist, and Dr. M. Daniele Fallin, a medical epidemiologist, both at Johns Hopkins University, who are working on another contributor to obesity: epigenetics.

Epigenetics is the study of changes in gene activity that do not involve mutations to DNA, but manage to survive through cell replication. These changes, which govern gene expression, occur in the cellular material that sits on top of the genome — the epigenome — and act as a dial, turning up and down the expression of various genes. (More on New Fat Fighting Machines: Real, FDA Approved)

Though most of your epigenome is static and determined at birth, a small subset changes over time, and these changes are now being ascribed to environment factors and even behavior — whether you smoke, feel stressed or eat an unhealthy diet, for instance. Some scientists argue that epigenetic changes — the most common type is known as DNA methylation — can be passed onto future generations.

Feinberg and Fallin’s paper, which involved 74 participants in a long-term study in Reykjavik, reports that certain patterns of epigenetic marks can be associated with a higher risk of obesity. The team began by mapping 4.5 million areas of the human genome. Of the 4.5 million locations, researchers found that 227 were distinct between people — like an epigenetic fingerprint. Two-thirds of those distinct locations remained constant over time, but one-third changed over the course of the 11-year study. Feinberg attributes these changes to environmental and behavioral influences.

“Once we figured out what changed over time, we thought, ‘Could they be related to disease?’ So we looked at BMI, just because it was quantitative and so significant even with a smaller sample size,” says Feinberg, referring to body mass index, a ratio of weight and height that is used to determine obesity.

What the researchers found is that some of the genetic methylation that occurred over the course of the study — involving the expression of 13 genes — was in fact related to BMI. Further research is necessary, but the findings are encouraging for future treatment and prevention of obesity, which could be tailored to match a patient’s specific epigenetic makeup. (More on See a gallery of five potassium rich foods you should looks out for)

Feinberg and Fallon are already studying the epigenetic signature of newborns (the age of participants in the current study ranged from 58 to 85 at the beginning) in an effort to predict the effects of gene expression associated with genetic methylation. Their future study may be able to determine which environmental factors create epigenetic differences between people and how those will affect health over the long term.

More on Time:

How Secondhand Cigarette Smoke Changes Your Genes

Obesity: You Can Beat Your Genes

How You can Change Your Genes