"Obesity genes": another candidate for leadership
A genetic explanation for the tendency to obesity has been found
Copper news based on the materials of Imperial College London:
Genetic study supports link between carbohydrate digestion and obesityThe tendency to develop obesity is genetically related to the body's insufficient ability to absorb carbohydrates, a large-scale study conducted by an international group of specialists has shown.
As it turned out, the chances of an individual becoming overweight are higher the fewer copies of the gene encoding the starch-splitting enzyme contained in saliva. The results of the study are published in the journal Nature Genetics (Falchi et al., Low copy number of the salivary amylase gene predisposes to obesity).
It is known that the AMY1 gene encoding the digestive enzyme alpha-amylase (salivary amylase, ptyalin) secreted by the salivary glands into the oral cavity, which breaks down high-molecular starch and other polysaccharides contained in food to the maltose stage, has a high variability in the number of copies (CNV) between individuals. It is believed that a large CNV of this gene appeared in humans during evolution as an adaptive response to the transition to a diet with a high starch content.
Researchers from Imperial College London (Great Britain), together with experts from other world scientific centers, analyzed the genetic data of almost half a thousand brothers and sisters from Sweden, selected according to the principle: one of the couple is obese, and the other is not. It was found that of the entire spectrum of genes affecting body mass index (BMI), the AMY1 gene has the highest degree of such influence.
The authors then analyzed the relationship between the number of copies of this gene in an individual on chromosome 1 and the risk of developing obesity based on genetic data from approximately five thousand residents of France and the UK. In addition, to confirm the results obtained for non-Europeans, a similar study was conducted based on genetic data from approximately 700 obese and normal BMI residents of Singapore.
As a result, a persistent inverse relationship was revealed between the number of copies of the AMY1 gene in a person and his individual tendency to obesity – the smaller the CNV, the higher the risk of obesity. Thus, people with four or fewer copies of AMY1 have about eight times higher risk of being overweight and obese than those with more than nine copies of this gene. The researchers estimated that each additional copy of AMY1 gives about a 20 percent reduction in the chances of developing obesity.
"For the first time, evidence of a genetic link between carbohydrate metabolism and BMI has been found," the authors conclude. "I think this is a very important discovery that speaks about the key role of the mechanism of assimilation of complex carbohydrates in the development of obesity," said one of the lead authors of the work, head of the Department of genomic Medicine at the School of Public Health at Imperial College London, Professor Philippe Froguel. – Further research is needed to find out whether and if so, how exactly the change in the ability to digest starchy foods affects BMI. In addition, we plan to look for links between the number of copies of AMY1 and other metabolic disorders, such as diabetes, since people with low CNV of this gene may also have genetically determined glucose intolerance."
Portal "Eternal youth" http://vechnayamolodost.ru31.03.2014