If you’ve ever experimented with a low-carb diet, you may have been amazed both by how effective it is, and how much intention it takes to minimize starch consumption in your diet. But new research suggests that if you’re someone with a soft spot for carbs like bread, muffins, and pasta, our longing for foods high in this macronutrient isn’t something to feel guilty about. In fact, cravings for carbohydrates might actually be etched in our genes.
In a new study published in the peer-reviewed journal Science in October 2024, researchers from the University at Buffalo and the Jackson Laboratory have traced the human love of carbohydrates back over 800,000 years. They’ve discovered that the AMY1 gene, which is responsible for producing the enzyme amylase that breaks down starch into glucose and also gives bread its taste, has been duplicating itself in our DNA since ancient times.
“The idea is that the more amylase genes you have, the more amylase you can produce and the more starch you can digest effectively,” explains Omer Gokcumen, PhD, study author and professor of biological sciences at University at Buffalo.
The study’s researchers used advanced genetic sequencing methods to examine DNA from 68 ancient humans, including a 45,000-year-old sample from Siberia. Their findings suggest that pre-agricultural hunter-gatherers already had an average of four to eight AMY1 copies per diploid cell. This means early humans roaming Eurasia were already equipped to digest starchy foods long before they started farming. The study also found that this genetic adaptation wasn’t unique to modern humans—Neanderthals and Denisovans, our ancient relatives, also had multiple AMY1 gene copies.
“The initial duplications in our genomes laid the groundwork for significant variation in the amylase region, allowing humans to adapt to shifting diets as starch consumption rose dramatically with the advent of new technologies and lifestyles,” Dr. Gokcumen notes in a UB press release on the study.
As humans began cultivating crops, particularly in Europe, the number of AMY1 copies increased over the past 4,000 years, likely due to grain-heavy diets. Those with higher AMY1 copy numbers were better equipped to digest starch, which helped provide them more energy and, in turn, improved their chances of survival and reproduction. “Their lineages ultimately fared better over a long evolutionary timeframe than those with lower copy numbers, propagating the number of the AMY1 copies,” Dr. Gokcumen says.
So, what does this mean for us today? Understanding the AMY1 variation offers a deeper look into our evolutionary past and could also provide fresh insights into metabolic health, particularly how our bodies manage starch digestion and glucose metabolism. Additional future research could also help explain why some people seem to thrive on carb-rich diets while others don’t.