In humans, the salivary amylase gene (AMY1) has been found to break down starches in our mouths, which is the first step to properly digesting starches and carb-rich foods. Humans carry a varied number of AMY1 on our first chromosome. Moreover, amylase is an enzyme that breaks starch down into glucose, so the more amylase genes you have actively producing, the more starch you can break down. Therefore, the AMY1 gene has been credited with shaping humans adaptation to starchy foods, ultimately diversifying our diet and allowing us to use more food resources.
Within their study of AMY1, researchers looked into 68 ancient human bodies (even one who lived 45,000 years ago) to see how far back these genetic variations went. The researchers noted that the hunter-gatherers had four to eight copies of AMY1. Curiously, this was before humans began to farm their foods, so we had already began to adapt to starches before growing wheat/potatoes. From the findings of this study, it is now argued that the different amounts are attributed to duplications made over 800,000 years ago (before humans split from Neanderthals and Denisovans). As we spread out globally, the amount of AMY1s began to be distinctly different between locations, for the amount is dependent on the environment around them (Thompson, 2024). Also, the average number of AMY1 copies have dramatically increased in the past 4,000 years because of our diet. Interestingly, because individuals with more AMY1 copies digest starches easier, they have been found to reproduce more and also may explain why the average amount has increased.
In all, this genetic variation opens up many opportunities for future research. Personally, I would be interested in looking at the amount of AMY1 copies in places that eat a lot of carbs (f.e. Italy and Japan). One researcher even said that our current understanding of metabolic health may change from these findings. She also noted that,"Future research could reveal its precise effects and timing selection, providing critical insights into genetics, nutrition and health” (Yilmaz, 2024). I look forward to seeing how these findings will be researched and if the metabolic effects of AMY1 could be replicated with other medications or fixed with new genetic editing.
Sources used:
https://www.usnews.com/news/health-news/articles/2024-10-18/love-bread-pasta-humans-hunger-for-carbs-has-ancient-roots
https://humgenomics.biomedcentral.com/articles/10.1186/s40246-017-0097-3
