Chinese scientists identify gene that may help protect against obesity

A 2022 study published in The Lancet ranked Chinese women 190th globally in obesity prevalence and Chinese men 149th.

While factors such as diet and developmental levels are undoubtedly important, a recent study led by Professor Jin Li and Associate Professor Zheng Hongxiang from Fudan University suggests that genetics may also be a factor.

The team analyzed 2,877 samples from three independent populations in the southwestern Guangxi region, eastern Jiangsu province and Henan in central China for the study, which was published in the Journal of Genetics and Genomics.

He identified a type of mitochondrial DNA known to be widespread in southern China and Southeast Asia that appears to act as a protective factor against obesity.

“Mitochondria are often referred to as the energy centers of the cell, generating 80 to 90 percent of the energy needed for various human behaviors. “Mitochondrial function has long been linked to obesity,” Jin wrote.

Unlike the DNA in the cell’s nucleus, which comes from both parents, the DNA in the mitochondria is generally inherited only from the mother. Compared to nuclear DNA, it is more likely to accumulate genetic mutations, which are often used in evolutionary analyses.

Jin and his colleagues performed association analyzes of 16 basal mitochondrial DNA haplogroups, genetic families that descend from a common ancestor.

They found that a specific variant group called M7 was consistently associated with a reduced risk of obesity. Further analysis identified a subgroup called M7b1a1 as the most likely source.

A 2019 study by Professor Kong Qingpeng of the Chinese Academy of Sciences, published in Molecular Biology and Evolution, found that this specific subgroup “was mainly distributed in southern China and mainland Southeast Asia and showed significant frequencies in Han Chinese individuals southern – about 5 to 14 percent”.

Jin said that a decreased mitochondrial function may be why M7b1a1 reduces the risk of obesity.

“Decreased mitochondrial functions represent less energy storage and more heat production, which may result in less weight gain,” he wrote in the paper.

The researchers also found that M7b1a1 appears to have undergone population expansion approximately 15,000 years ago.

Jin said this further supports their hypothesis, adding: “M7b1a1 carriers with greater heat generation may have adapted to the cold climate in the Ice Age well, which may have been evolutionarily favorable for selection.” natural positive.

“Our findings… provide new insights into the genetic basis of obesity-related traits, increasing our understanding of how genetics can influence body fat distribution and obesity risk.”