A New Study from the U.S. Reveals Why Some People Process Starch Better Than Others
According to a research team from the University of Buffalo and the Jackson Laboratory, if you constantly struggle to manage your starch intake, the reason may lie in differences in amylase genes.
These genes play a crucial role in breaking down carbohydrates, which is the first step in metabolizing starchy foods like bread and rice.
As published in the scientific journal Science, this genetic factor varies among individuals.
Individual starch processing capabilities are largely influenced by genetic factors – (Illustration AI: THU ANH).
“The more amylase genes you have, the more amylase you can produce, allowing you to digest a larger amount of starch more effectively,” explained Professor Omer Gokcumen from the University of Buffalo, a co-author of the study.
Their research focused on the duplication of the salivary amylase gene (AMY1) in humans over time.
They discovered that the increase in AMY1 gene copies in humans might have begun around 800,000 years ago, long before the advent of agriculture, and even before the emergence of modern humans (Homo sapiens) approximately 300,000 years ago.
To reach this conclusion, the authors analyzed the DNA of 68 ancient individuals, including a 45,000-year-old specimen from Siberia. They found that pre-agricultural hunter-gatherers had an average of 4-8 AMY1 copies.
This suggests that humans traversed the Eurasian continent with varying numbers of high AMY1 gene copies before they began to domesticate plants and consumed an excess of starch.
They also found that AMY1 duplication occurred in Neanderthals and Denisovans, two extinct human species that interbred with our ancestors.
According to Dr. Gokcumen, this is how humans generally evolved to adapt to new lifestyles, and this change persists to this day.
A previous study from the University of California indicated that Europeans have increased their average number of AMY1 gene copies from 4 to 7 over the past 12,000 years.
“After the initial duplication, leading to 3 AMY1 copies in a cell, the amylase locus became unstable and began to produce new variants,” explained Dr. Charikleia Karageorgiou, another co-author.
He added: “From 3 AMY1 copies, you can have up to 9 copies, or even revert back to 1 copy for each haploid cell.”
While natural selection has favored human populations with a higher number of AMY1 copies, making them more adaptable to starchy diets, we still exhibit significant differences today.
According to News Medical, the authors noted that this discovery opens up exciting opportunities to explore the impact of this genetic variant on metabolic health, specifically related to the mechanisms involved in starch digestion and glucose metabolism.
This will provide important insights into genetics, nutrition, and help us develop more tailored health care strategies for different groups of people.
