The surprising factor that makes many people eat a lot of starch and still stay healthy

A new study from the US reveals why some people seem to process their carbohydrate intake better than others.

According to a research team from the University of Buffalo and the Jackson Laboratory (USA), if you are always struggling to find ways to reduce the amount of starch you take in, the cause may come from differences in amylase genes .

They play a role in breaking down carbohydrates , the first step in metabolizing starchy foods like bread or rice.

According to an article published in the scientific journal Science , this genetic factor is not the same in everyone.

Each person's ability to process starch depends largely on genetic factors - (Illustration by AI: THU ANH).

"The more amylase genes you have, the more amylase you can produce and the more efficiently you can digest starch," explains co-author Professor Omer Gokcumen of the University at Buffalo.

Their study focused on how the salivary amylase gene (AMY1) duplicates over time in humans.

They found that the increase in AMY1 copies in humans may have begun 800,000 years ago, before the advent of farming, and 300,000 years before modern humans (Homo sapines) appeared.

To come to this conclusion, the authors analyzed the DNA of 68 ancient people, including a 45,000-year-old specimen from Siberia, and found that pre-agricultural hunter-gatherers had an average of 4-8 copies of AMY1.

This suggests that humans were roaming across Eurasia with a variety of high AMY1 copy number variants before they began domesticating plants and eating an abundance of starch.

They also found that the AMY1 duplication also occurred in Neanderthals and Denisovans, two extinct ancient human species that mixed with our ancestors.

According to Dr. Gokcumen, that is how humans in general have evolved to adapt to new lifestyles and that change still exists today.

A previous study from the University of California (USA) showed that Europeans increased the average number of AMY1 copies from 4 to 7 over the past 12,000 years.

"After the initial duplication, which results in three copies of AMY1 in a cell, the amylase locus becomes unstable and starts to generate new variants," explains co-author Dr Charikleia Karageorgiou.

'From three copies of AMY1, you can get up to nine copies, or even back to one copy per haploid cell,' he continued .

Although natural selection has favored populations with more copies of AMY1, which makes them better adapted to a starchy diet, we are still very different today.

News Medical quoted the authors as saying that this discovery will open up exciting opportunities to explore the impact of this genetic variant on metabolic health, or more specifically, the mechanisms involved in starch digestion and glucose metabolism.

This will provide important insights into genetics and nutrition and help us develop more appropriate health care strategies for each group of people.