The largest genetic search for “obesity genes” in people of African ancestry has led to the discovery of new regions of the human genome that influence obesity in these populations and others.
The study appears in the journal Nature Genetics. Led by researchers at the Keck School of Medicine of USC and the University of North Carolina’s Gillings School of Global Public Health, the work was the collaboration of hundreds of scientists worldwide.
“What we found in this study sheds new light on the genes that can influence obesity,” said the study’s co-principal investigator, Kari North, associate professor of epidemiology at UNC’s Gillings School. “[We discovered] three new genetic variants that are not only associated with body mass index (BMI) in populations with African ancestry but that also have implications for other populations.”
Specifically, the study involved more than 70,000 men and women of African ancestry. Within that population, researchers were able to identify three new genetic variants, known as single nucleotide polymorphisms (SNPs), which are associated with BMI and obesity in the sample population. Also of interest was the fact that the SNPs appear commonly within the population and also appear among those with no known African ancestry.
“While having these risk SNPs does not mean the individual will have a higher BMI or become obese, it does signal a predisposition,” said Christopher Haiman, professor of preventive medicine at the Keck School. “Just to be clear, these genes account for a very small fraction of the differences in BMI noted between individuals in the population. Poor diet and reduced physical activity continue to be the main driving forces for obesity.”
However, North said, these genes are indicators of unique biological processes that may lead to increased BMI and obesity. Their identification could lead to the development of medicines to reduce or even prevent obesity.
“It’s an important finding,” North said. “It provides substantial evidence that genes can influence obesity and that this genetic predisposition likely is shared across populations. This research also opens the door for more genetic studies and an examination of other potential shared traits in diverse populations.”