Our modern obsession with starchy foods, such as bread, pasta, and potatoes, may be deeply rooted in the DNA of ancient humans. Recent research conducted by scientists from the University of Buffalo (UB) and the Jackson Laboratory (JAX) in the U.S. reveals that the ability to digest starch-rich foods may have developed in humans long before we started farming, and possibly even before the evolutionary split from Neanderthals. This discovery provides fresh insights into the evolution of our diets and how our genes may have shaped our long-standing love for carbohydrates.

For decades, researchers have known that humans possess multiple copies of the gene responsible for producing salivary amylase, an enzyme that starts breaking down starch as soon as it enters the mouth. Starches are complex carbohydrates, found not only in grains like wheat, rice, and corn, but also in vegetables, fruits, and tubers like potatoes. The digestion process begins with the enzyme amylase, which breaks down these carbohydrates into simple sugars such as glucose, providing a crucial energy source.

While modern farming practices have expanded the availability of carbohydrate-rich foods, this research suggests that the genetic foundation for our carb cravings was laid much earlier in human history. The UB and JAX study proposes that the gene responsible for starch digestion, known as AMY1, may have duplicated more than 800,000 years ago. This gene duplication likely occurred before humans even split from Neanderthals, giving ancient humans an advantage when it came to processing the starchy foods available in their environments.

What Is Gene Duplication?

Gene duplication is a mutation that results in one or more copies of a gene being produced. In the case of the AMY1 gene, multiple duplications allowed early humans to produce higher levels of amylase in their saliva, equipping them to digest starch more efficiently. The more copies of the gene an individual has, the better they are at processing starchy foods.

The significance of this genetic adaptation cannot be overstated. In times when food sources were scarce, the ability to break down starches quickly into usable energy would have been a vital survival trait. With each meal, early humans who had more copies of the AMY1 gene could more effectively extract energy from starchy plants, which may have allowed them to thrive in environments where these foods were abundant.

The researchers behind this study, led by Professor Omer Gokcumen from UB, analyzed the genomes of 68 ancient humans, including a 45,000-year-old sample from Siberia. They discovered that even before agriculture became widespread, ancient hunter-gatherers already carried multiple copies of the AMY1 gene. These findings suggest that humans roaming across Eurasia thousands of years ago had the genetic tools to digest starch efficiently, long before they began farming and cultivating carbohydrate-rich crops.

One of the most groundbreaking discoveries from this research is that gene duplications in the AMY1 region didn’t just occur in modern humans. Neanderthals and Denisovans, two close evolutionary relatives of modern humans also had these duplications. This indicates that the genetic capacity to digest starch may have been an important feature in the diets of multiple human species, playing a key role in their survival and adaptation to different environments.

While hunter-gatherers already had some copies of the AMY1 gene, the rise of agriculture approximately 12,000 years ago likely accelerated the evolution of starch digestion. The development of farming dramatically increased human consumption of starches, particularly from grains and root vegetables, which became staple foods in many societies.

According to the study, there was a notable surge in the average number of AMY1 gene copies in European farmers over the past 4,000 years. This increase in gene duplications may have been driven by the starch-heavy diets that came with agricultural practices. As populations began to rely more heavily on grains like wheat, barley, and rice, individuals with more copies of the AMY1 gene may have had a nutritional advantage, leading to the spread of this trait through natural selection.

Kwondo Kim, one of the lead authors of the study from the Lee Lab at JAX, explained that the initial duplications of the AMY1 gene, which occurred more than 800,000 years ago, laid the groundwork for human adaptation to starch-rich diets. Over time, as new technologies and lifestyles emerged, starch consumption rose dramatically, and those with more copies of the gene were better able to process these foods.

The research raises intriguing questions about the genetic basis of modern dietary preferences. If our ancient ancestors were already well-adapted to digesting starchy foods, could this explain why so many people today crave bread, pasta, and other carbohydrate-rich foods? It’s possible that the genetic predispositions developed by early humans have carried over into modern populations, influencing our tastes and dietary choices in ways we may not fully understand.

However, it’s important to note that while the AMY1 gene enables more efficient starch digestion, it doesn’t necessarily mean that a high-carbohydrate diet is ideal for everyone. Modern lifestyles, which often involve lower levels of physical activity compared to our hunter-gatherer ancestors, mean that excessive carbohydrate consumption can lead to health issues such as obesity and diabetes. The challenge for individuals today is to balance their genetic predispositions with the demands of modern living.

One of the most interesting aspects of this research is how it sheds light on the connection between genetics and the sensory experience of eating. Amylase, the enzyme produced by the AMY1 gene, not only helps break down starch into glucose but also plays a role in the taste and texture of starchy foods. For example, when you eat a slice of bread or a bowl of pasta, amylase starts working in your mouth, breaking down the starch and creating a subtle sweetness that enhances the flavor of the food.

This process may explain why starchy foods have become such an important part of human diets around the world. The sensation of eating bread, pasta, or rice may tap into an ancient, genetically programmed response that makes these foods particularly satisfying and enjoyable.

The findings from this study open the door to further research on how ancient genetic adaptations continue to shape our modern diets. Scientists are particularly interested in understanding how genetic variation in the AMY1 gene region affects individuals responses to different types of carbohydrates. Some people may be better equipped to handle starch-rich diets, while others may struggle with health issues related to carbohydrate metabolism.

In the future, personalized nutrition plans based on an individual’s genetic makeup could become more common. By understanding how genes like AMY1 influence digestion and metabolism, researchers may be able to develop dietary recommendations tailored to each person’s genetic profile, optimizing their health and well-being.

Our love for bread, pasta, and other starchy foods may be more than just a modern culinary preference. It could be the result of genetic adaptations that began over 800,000 years ago, when our ancestors first developed the ability to digest starch in the mouth. This ancient genetic legacy has shaped our diets for millennia, influencing not only what we eat but also how we experience the taste and satisfaction of food.

As we continue to learn more about the connections between our genes and our diets, it’s clear that the story of human evolution is, in many ways, a story about food. From the earliest hunter-gatherers to modern-day bread lovers, the ability to digest starch has been a defining feature of the human experience, a testament to the power of adaptation and the enduring influence of our ancient DNA.