Ancient DNA may be the reason you love bread and chips, according to a recent study. Researchers suggest that humans may have developed the ability to digest carbohydrates like bread and chips in the mouth long before the advent of farming, and possibly even before the split from Neanderthals.
The study indicates that the gene responsible for digesting starch in saliva may have duplicated over 800,000 years ago, laying the foundation for the genetic changes that influence our diets today. This duplication of genes enables the breakdown of complex carbohydrates, including foods like potatoes, rice, fruits, and vegetables, in the mouth.
Having multiple copies of these genes allows individuals to efficiently break down carbohydrates. The challenge for researchers has been to determine how and when the gene duplications occurred. The new research, led by the University of Buffalo (UB) and the Jackson Laboratory (JAX) in the US, suggests that the duplication of the salivary amylase gene (AMY1) may have occurred long before the dawn of agriculture.
The enzyme amylase not only breaks down starch into glucose but also contributes to the taste of bread. Professor Omer Gokcumen from UB explains that having more amylase genes leads to increased starch digestion efficiency.
Examining the genomes of 68 ancient humans, including a 45,000-year-old sample from Siberia, the researchers found evidence of duplicated copies of the gene in pre-agricultural hunter-gatherers. This suggests that humans across Eurasia possessed a variety of these genes even before the era of plant domestication.
Notably, the study also found that Neanderthals and Denisovans carried duplicated AMY1 genes. The initial gene duplications occurred more than 800,000 years ago, indicating a timeline that predates the split between humans and Neanderthals.
The research underscores the significant variation in the amylase region, allowing humans to adapt to dietary shifts as starch consumption increased with evolving lifestyles. European farmers, in particular, experienced a surge in the average number of AMY1 gene copies over the past 4,000 years due to their starch-rich diets.
The study, published in the Science journal, delves into the detailed mapping of the AMY1 gene region using genome sequencing. The findings shed light on the ancient origins of our love for carbohydrates like bread and chips, tracing it back hundreds of thousands of years.
As we unravel the mysteries of our genetic history, it becomes clearer why our affinity for certain foods like bread and chips is deeply rooted in our DNA. This research opens up new perspectives on how human evolution has influenced our dietary preferences and provides insight into the complex interplay between genetics and food consumption.