Our Ancient Love for Carbs: New Insights into Human Diet Evolution

Our Ancient Love for Carbs: New Insights into Human Diet Evolution

A groundbreaking study published in Science has revealed that our affinity for carbohydrates may date back far earlier than previously thought, potentially even before the emergence of modern humans. This research challenges the long-held belief that our ancient ancestors primarily thrived on a protein-rich diet, feasting on mammoth steaks and other meats, which was thought to be essential for brain development.

Recent archaeological findings have shifted this narrative, suggesting that ancient humans had a taste for carbohydrates, often roasting tubers and other starchy foods. Evidence from bacteria found in ancient teeth points to a long-standing relationship with these energy-rich sources.

Tracing the Origins of Carbohydrate Digestion

The study, led by researchers at The Jackson Laboratory in Connecticut and the University of Buffalo, focuses on the evolution of the AMY1 gene, which helps humans digest starch by producing the enzyme amylase. This gene allows us to break down complex carbohydrates into simple sugars, essential for energy. Interestingly, the study found that variations of this gene existed long before agriculture began, suggesting that our ancestors were adapting to carbohydrate-rich diets much earlier than expected.

Feyza Yilmaz, the study’s lead author, explained that they aimed to pinpoint when the duplication of the AMY1 gene occurred. Previous studies indicated a link between the number of AMY1 copies and amylase production in saliva, sparking curiosity about its relationship to the rise of agriculture. Their analysis of 68 ancient genomes revealed that hunter-gatherers had an average of four to eight copies of the AMY1 gene as far back as 45,000 years ago, indicating a pre-agricultural preference for starch.

A Shared Genetic Heritage

Moreover, the study discovered that Neanderthals and Denisovans—two extinct human relatives—also possessed multiple copies of the AMY1 gene, suggesting this trait originated in a common ancestor over 800,000 years ago. This discovery emphasizes that an inclination towards starchy foods was likely advantageous for various human species as they adapted to their environments.

The research also highlighted that the number of AMY1 gene copies increased significantly in the last 4,000 years, likely driven by natural selection as humans transitioned from hunting and gathering to farming grains.

Reassessing Our Dietary Roots

The findings support the theory that carbohydrates, rather than proteins, played a critical role in fueling the development of the human brain. Taylor Hermes, an anthropologist not involved in the study, noted that the increased ability to break down starch may have provided the energy needed for significant brain growth during human evolution.

Despite the challenges in tracing dietary changes over millennia, experts like Christina Warinner from Harvard University praised the study for shedding light on crucial moments in our dietary history. “This genomic sleuthing is helping to time-stamp major milestones in our long-standing relationship with starch,” she said.

In conclusion, this research not only redefines our understanding of ancient diets but also underscores the importance of carbohydrates in human evolution, revealing that our love affair with carbs is far more ancient than we ever imagined.