Research by UNC-Chapel Hill and Duke University has found obesity may have a genetic component.
A study by Damaris Lorenzo, a professor at the UNC School of Medicine, and Vann Bennett, a biochemistry professor at Duke, showed that ankyrin-B, a gene responsible for coding the ankyrin-B protein, can cause fat cells in mice to absorb glucose faster due to deficiencies in the gene.
Bennett discovered the gene about 30 years ago. It was initially thought to exist mainly in brain tissue, but it was found in many types of cells 10 years later. When the researchers noticed some of the mice beginning to gain weight, they conducted further studies to examine the gene in relation to cardiac arrhythmia.
To further study the mice weight gain, the researches gave a mouse a human cardiac arrhythmia. The mouse gained weight as it got older despite no changes in diet and exercise.
“Damaris then found that if she took cells from these mice and grew them in subculture — no food or anything, just growing cells in culture — the cells became fat,” Bennett said. “So then we realized we had a very interesting phenomenon with cellular basis, not to do with eating too much or eating the wrong food. It was something intrinsically different about these cells.”
Researchers are still attempting to learn more about the role of the gene. Bennett said there was a test conducted where researchers knocked the gene out of fat protein and the mice still gained weight. Young animals also gained weight when they were given high-fat food.
“We don’t fully understand this aspect, but it kind of fits the human condition where our diet now includes a lot of fast food, high-fat food,” Bennett said. “If people are like the mice, people with the mutation would be more susceptible to fast food diets.”
Bennett said about six million Americans have ankyrin-B mutations. While this gene does not explain the obesity epidemic happening in America, he said it does help show there are many causes for obesity.
It is not yet proven if the findings in Lorenzo and Bennett’s research can be applied to humans, but if the ankyrin-B mutation displays the same in humans as it does in mice, then people with the mutation would be more likely to put on weight. Though they may not eat as much and even have low fat diets, they may still gain weight as they get older. Bennett said this weight can be very hard to lose.
Lorenzo said if the results are similar in humans, it will allow for a way for people to be screened for the mutation and for further research to take place to find ways of counteracting the mutation.
“If someone is proven to be genetically obese, then the treatment would depend, in part, on what the molecular mechanism is that is causing them to be obese," she said. "Then, based on that, they would work with clinicians, nutritionists and exercise specialists to personalize a plan that addresses the best prevention and care available at that point.”
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