In 1826, Anthelme Brillat-Savarin, a French lawyer and politician who nonetheless gained fame as a gastronome, wrote in his book “Physiologie du Gout, ou Meditations de Gastronomie Transcendante:” “Tell me what you eat and I will tell you what you are?.
In 1836, the German philosopher and anthropologist Ludwig Feuerbach penned the line, “A man is what he eats,” in a noted essay of his.
American health food and weight loss pioneer Victor Lindlahr reverberated “You are what you eat” in 1942, and in the 60s, the sweeping movement of the hippies made the same phrase one of their main slogans for healthy eating.
What was empirically grasped by all these completely different people living in different times is now scientifically grounded by researchers at the University of Oxford. In a groundbreaking research that was published in the journal Jenome Biology.
The University of Oxford Department of Plant Sciences unveiled genetic evidence that our diets can affect the DNA sequences of our genes, and that the folk truth of “We are what we eat” is backed by hard physiological evidence — always on a generational timescale.
As Emily Seward, a doctoral candidate in Oxford’s Department of Plant Sciences, explained to Olive Oil Times, to test this hypothesis researchers based their study on a model system comprising simple groups of parasites, eukaryotic parasites (Kinetoplastida) and bacterial parasites (Mollicutes). “Parasites that share a common ancestor but for reasons not quite well understood have evolved to eat quite different foods and infect different hosts,” said Seward.
Using novel mathematical models the scientists developed themselves, they were driven to the conclusion that different levels of nitrogen, as manifested in a parasite’s diet, did affect DNA composition. Parasites with diets low in nitrogen and high in sugar diets were distinguished by DNA sequences that made use of less nitrogen than parasites with diets high in nitrogen and protein.
The results highlighted the scientifically emerging relationship between cellular metabolism and evolution. They also showed that it is feasible to predict the diets of resembling organisms by analyzing the DNA sequence of their genes.
Most of all, the study proved that by adopting different diets we can indeed change our genetic make-up, but (reality check) not as easily as we would love to imagine: Though we can become healthier by switching towards healthier nutritional choices, we cannot manipulate our DNA to the extent previous information is wholly erased and replaced by new — at least over the course of our own lifetime.
“There are so many factors that can influence the DNA sequence of an organism. In the research, we are talking about small dietary changes that accumulate over the course of previous generations. It’s a generational thing in that many generations take small steps toward changing their genetic map. A drastic change cannot take place in a lifetime. You can become healthier, but you will not drastically change your DNA,” said Seward.