The research, published Nature ecology & evolution, looked at how dietary changes impacted the human gene thousands of years ago. It shows that the introduction of plant-focused diets thousands of years ago in Europe led to changes in the human gene.
Those behind the research say its findings have implications for the field of nutrigenomics, which studies how diet, nutrient supplements and environmental factors such as chemicals interact with an individual’s genes and influence their health outcomes.
It is the latest development in what scientists hope will one day lead to doctors and other primary carers being able to tailor individual’s diets to their genes to help prevent diseases and improve health.
However, senior author of the paper, Dr Alon Keinan of Cornell University, has railed against sham operators which he claims are undermining the growing field of nutrigenomics and personalised nutrition.
The nutrigenomics field is expanding globally but Keinan said the field could be potentially undermined by a number of sham companies, which are operating in the field without applying sufficient scientific rigour to their work.
Speaking to NutraIngredients, Keinan said: “I think the health implications from nutrigenomics are so large and relatively immediate that it should be relatively easy to get funding for this type of research, as long as it’s serious research.
“You might see in this field of nutrigenomics or in personalised nutrition a lot of companies that are not based on any scientific evidence. It is also a field that it is easy to pretend to know what you are doing.
“Within the scientific community it is pretty clear, who is serious and who is not.”
Keinan did not give names of companies he deemed rogue but he said such operators could potentially undermine the industry as a whole.
“If there is any company that ends up being convincing enough and does serious damage to clients then I think they might damage the image of the field overall,” he told us.
Commenting on the findings of the study, Keinan said: "The study shows what a striking role diet has played in the evolution of human populations.”
The study findings reveal how vegetarian diets of European farmers led to a heightened frequency of an allele which encodes cells to produce enzymes which helped farmers metabolise plants.
These farmers boasted better health and allowed them to have more children, passing the gene variant to them. The FADS1 gene found in these vegetarian farmers produces enzymes that play a crucial role in the biosynthesis of omega-3 and omega-6 long-chain polyunsaturated fatty acids (LCPUFA), which are key for human brain development, controlling inflammation and immune response.
While omega-3 and omega-6 LCPUFA can be obtained directly from animal-based diets, they are absent from plant-based diets.
Vegetarians require FADS1 enzymes to biosynthesize LCPUFA from short-chain fatty acids found in plants (roots, vegetables and seeds).
Analysis of ancient DNA revealed that prior to humans' farming, the animal-based diets of European hunter-gatherers mainly favoured the opposite version of the same gene, which limits the activity of FADS1 enzymes and is better suited for people with meat and seafood-based diets.
An examination of the frequencies of these alleles in Europeans showed that the prevalence of the allele for plant-based diets decreased in Europeans until the Neolithic revolution, after which it rose significantly.
At the same time, the opposite version of the same gene found in hunter-gatherers increased until the advent of farming, after which it declined sharply.
Further research will focus on the links between genetic variation, diets and health.
Source: Nature ecology & evolution
Published online ahead of print, doi: 10.1038/s41559-017-0167
“Dietary adaptation of FADS genes in Europe varied across time and geography”
Authors: Kaixiong Ye, et al