Ancient Andes People Evolved to Digest Starch Better After Domesticating Potatoes

In a discovery shedding light on human adaptability, a 2026 study published by Live Science reveals that Indigenous Andeans have evolved to possess more copies of a gene critical for starch digestion, a trait linked to the domestication of potatoes over 10,000 years ago. This genetic adaptation, driven by natural selection, may explain why Andean populations historically thrived on a diet rich in tubers, offering insights into the interplay between diet, evolution, and modern health.

How Did Andeans Develop Enhanced Starch Digestion?

The study identifies a genetic variation in the AMY1 gene, which codes for salivary amylase—a enzyme that breaks down starch. Researchers found that Indigenous Andeans typically have 10 to 20 copies of this gene, far exceeding the 2 to 6 copies common in most populations. This surplus likely arose as an evolutionary response to the agricultural shift toward potatoes, a staple crop that became central to Andean diets after its domestication around 8,000 BCE.

“The high number of AMY1 copies in Andean populations suggests a long-term adaptation to a starch-heavy diet,” explains the study. “This genetic trait would have provided a survival advantage by improving the efficiency of starch digestion, which is crucial in regions where tubers form a significant portion of caloric intake.”

What Does This Mean for Modern Health?

The findings have implications for understanding how diet shapes genetic evolution and vice versa. While the AMY1 gene’s role in starch digestion is well-documented, the study highlights how environmental pressures can drive genetic changes over millennia. For modern populations, this research underscores the complexity of human metabolism and the potential risks of diets that diverge sharply from ancestral patterns.

“Populations with high AMY1 copy numbers may metabolize carbohydrates more efficiently, but this could also make them more susceptible to metabolic disorders if their diet shifts toward processed foods,” the study notes. “This suggests that genetic predispositions should be considered in personalized nutrition strategies.”

How Was the Study Conducted?

Researchers analyzed DNA samples from Indigenous Andean communities, comparing them to global genetic databases. They focused on the AMY1 gene’s copy number variation and correlated it with historical dietary practices. The study also examined ancient Andean agricultural records to trace the timeline of potato domestication and its integration into local diets.

“By combining genetic data with archaeological evidence, we were able to link the AMY1 gene’s expansion to the agricultural practices of the Andes,” the study states. “This interdisciplinary approach provides a clearer picture of how human populations adapt to their environments.”

Why Does This Discovery Matter?

This research contributes to a growing body of evidence that diet and genetics are deeply intertwined. It challenges the notion of a one-size-fits-all approach to nutrition, emphasizing the importance of considering ancestral dietary patterns when addressing health outcomes. For example, populations with high AMY1 copy numbers might benefit from diets rich in complex carbohydrates, while those with lower copy numbers may require different nutritional strategies.

The study also raises questions about the broader impacts of globalization on traditional diets. As Indigenous communities face increasing pressure to adopt Western eating habits, understanding their genetic adaptations could inform efforts to preserve health while navigating cultural changes.

“This work highlights the need to respect and study traditional diets,” the researchers conclude. “They represent centuries of adaptation and could hold valuable lessons for addressing modern health challenges.”