This “vegetarian allele” likely evolved over time.
Researchers from Cornell University have revealed intriguing evidence that suggests our bodies adapt over time to the foods we eat — they discovered a genetic variation or “vegetarian allele” in populations with a history of a plant-based diet.
According to the study results, which are published in the journal Molecular Biology and Evolution, the variation appears to have developed over hundreds of generations of vegetarians, and the allele was found to have an insertion of 22 bases, which are DNA building blocks, within the gene.
Interestingly, in Inuit populations of Greenland (which eat seafood-heavy diets), the researchers found an adaptation that’s opposite to the one found in vegetarian populations — the insertion found in the vegetarian allele was deleted in the seafood allele, suggesting that our bodies really do adapt to our diets over time.
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"It is possible that in the history of human evolution, when people migrated to different environments, sometimes they ate a plant-based diet and sometimes they ate a marine-based diet, and in different time periods these different alleles were adaptive," said one of the researchers, Kaixiong Ye, in a press release.
The scientists looked at samples of 234 primarily vegetarian Indians and 311 participants from the United States. After comparing the two samples, they found that the vegetarian allele was present in 68 percent of the Indians but only 18 percent of the Americans.
Additionally, the team looked at data from the 1000 Genome Project, and found that the same vegetarian allele was present in 70 percent of South Asians, 53 percent of Africans, 29 percent of East Asians, and 17 percent of Europeans, which solidifies the connection between the presence of the vegetarian allele and places where vegetarian diets are more common.
"One implication from our study is that we can use this genomic information to try to tailor our diet so it is matched to our genome, which is called personalised nutrition."
So what do these diet-based genetic variations mean for our health?
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Interestingly, the researchers say that the vegetarian allele allows vegetarian populations to more efficiently process omega-3 and omega-6 fatty acids and convert them into compounds that help with brain development.
“Northern Europeans have a long history of drinking milk and they absorbed enough end products from milk for long-chain fatty acid metabolism so they don’t have to increase capacity to synthesize those fatty acids from precursors,” said Ye.
However, it’s not all good news — the vegetarian allele also increases the risk of the creation of inflammatory acids which are linked to heart disease and colon cancer, particularly in combination with vegetable oils.
"Changes in the dietary omega-6 to omega-3 balance may contribute to the increase in chronic disease seen in some developing countries," one of the researchers, Tom Brenna, told The Telegraph. "The message for vegetarians is simple. Use vegetable oils that are low in omega-6 linoleic acid such as olive oil."
This study is the first to connect this insertion allele with a vegetarian diet, so perhaps continued research into the genetic variations that have evolved over time will yield some interesting findings about the long-term effects of our diets.
