Research Suggests Ancient DNA Could Be the Reason Behind Our Love for Bread and Chips
A recent study indicates that ancient DNA may be the driving force behind our affinity for carbohydrates such as bread and chips. The research suggests that humans might have acquired the ability to digest these foods in the mouth long before the practice of farming began, possibly even predating the split from Neanderthals.
The study reveals that over 800,000 years ago, genes responsible for digesting starch in complex carbohydrates, like potatoes, rice, and certain fruits and vegetables, began to duplicate. This duplication, a type of mutation, paved the way for the genetic adaptations that influence our dietary behaviours today.
For some time, experts have understood that humans carry multiple copies of a gene that aids in breaking down starch in complex carbohydrates. This initial breakdown in the mouth is the first step in the digestion process, and individuals with more copies of these genes are better equipped to metabolise carbohydrates effectively.
The latest research, led by the University of Buffalo (UB) and the Jackson Laboratory (JAX) in the US, indicates that the duplication of the gene, known as the salivary amylase gene (AMY1), likely played a crucial role in human adaptation to starchy foods. This genetic evolution is thought to have occurred more than 800,000 years ago, long before the advent of farming.
Amylase, an enzyme found in saliva, not only aids in breaking down starch into glucose but also contributes to the taste of bread. Omer Gokcumen, the corresponding author and professor at UB, explained that individuals with more amylase genes can produce more of the enzyme, enhancing their ability to digest starch effectively.
Analysing the genomes of 68 ancient humans, including a 45,000-year-old sample from Siberia, the researchers discovered that pre-agricultural hunter-gatherers already possessed duplicated copies of the gene. This finding implies that a wide range of these genes was present in humans across Eurasia long before the practice of farming and excessive starch consumption.
Moreover, the study uncovered that Neanderthals and Denisovans also had duplications of the AMY1 gene, hinting that this genetic adaptation could have occurred over 800,000 years ago. The surge in the average number of AMY1 copies among European farmers in the past 4,000 years suggests the impact of starch-rich diets on genetic variation associated with carbohydrate digestion.
Published in the Science journal, the study employed genome mapping and sequencing to provide a detailed insight into the AMY1 gene region. As research continues to unravel the mysteries of ancient DNA and its implications on modern dietary habits, scientists are discovering the intricate relationship between genetic evolution and our love for carbohydrates.