A new study, published in the journal Nature Genetics, shows that the risk of obesity may be linked to the ability to digest carbohydrates. The study was performed by researchers from the King’s College and Imperial College in London and suggests that future dietary advice may need to be tailored to the individual’s digestive system.
The study was focused on a gene called AMY1, which is known to regulate the salivary amylase enzyme. Salivary amylase plays a significant role in the digestion of carbohydrates at the start of the digestion process. Usually, people have two copies of each gene in the DNA; however, researchers say that, unlike other genes, copies of the AMY1 gene can wildly vary between individuals.
For the study, more than 6,000 people were examined from England, France, Sweden and Singapore. The findings suggest that those with a low number of the AMY1 gene in the DNA were more likely to become obese compared to those with more copies of the AMY1 gene.
Dr. Mario Falchi, one of the authors of the study, says, “The findings should be able to help us to tackle obesity in better ways, as we are starting to develop a clear picture of the combination of genetic factors, which affect metabolic and psychological processes, contributing to the risk of becoming obese.”
Previous studies have shown that the risk of obesity is linked to genes that act in the brain, resulting into differences in appetite; however, never before have researchers examined whether it depends on the ability to digest carbohydrates.
Dr. Tim Spector, lead investigator, says, “The findings are very exciting, as we now discovered how the tools in the metabolism vary between individuals and its coding can have a large impact on the weight.” Researchers say the findings could be groundbreaking, as it might be useful for treatment of overweight and obesity. Spector adds, “We can finally move away from the idea that one size fits all when it comes to diets. In the future, dietitians may be able to perform a simple saliva test to measure the levels of the AMY1 gene. With these results, they can offer their clients a diet that is shaped to their body’s needs. These scenarios may be a long way away, but the study is a first step in knowing that people digest food differently.”
According to the study’s findings, an individual needs at least four copies of the AMY1 gene to avoid a risk of becoming obese. Their risk is approximately eight times higher than those who have at least nine copies of the AMY1 gene. Researchers estimated that with every copy of the gene, there was a 20 percent decrease in the risk of becoming obese.
Researchers say they will continue to perform further studies in order to understand if altering the ability to digest carbohydrates may improve the risk of obesity and whether there is a link between this gene and other metabolic disorders, including diabetes. Those with a low number of the AMY1 gene may be glucose intolerant, according to researchers of the study.
By Diana Herst