Diet, digestion and human evolution: Your ideal healthy diet depends on your genes

A study carried out by researchers at Cornell University has revealed that a dietary transition among Europeans, which started thousands of years ago, has triggered genetic changes that helped the body cope with the dietary trends. According to scientists, ancient European populations were primarily hunter-gatherers that ate animal-based diets and some seafood. However, the onset of farming in southern Europe about 8,000 years ago has prompted farmers to shift to a plant-heavy diet.

The researchers have analyzed ancient DNA in order to determine the effects of dietary changes before and after the Neolithic revolution. The scientists have discovered that the alleles for plant-based diet has significantly declined prior to the advent of farming, when people predominantly consumed animal meat and seafood. The research team also observed that the DNA of ancient European hunter-gatherers favored a diet based on animal meat.

However, the experts discovered an inverse effect after the introduction of farming. The research team notes that the alleles for plant-based diet significantly increased after the Neolithic revolution, while the alleles for meat-based diet has demonstrated a steep decline during the same period. According to the researchers, the findings have potential implications on the growing field of nutrigenomics. Examining a person’s ancestry may one day enable doctors to modify a patient’s diet based on his genetic make up in order to boost health and prevent diseases.

“I want to know how different individuals respond differently to the same diet…in the future, we can provide dietary recommendations that are personalized to one’s genetic background,” lead author Kaixiong Ye states in a university press release.

Genetic testing may one day effectively identify which diet works best

Research presented at The Allied Genetics Conference in June 2016 revealed that a person’s genetic make up may influence the body’s response to certain diet plans and may one day determine which one actually works. (Related: Confirmed by science: You really can change your DNA – and here’s how.)

“There is an over-generalization of health benefits or risks tied to certain diets. Our study showed that the impact of the diet is likely dependent on the genetic composition of the individual eating the diet, meaning that different individuals have different optimal diets. We’ve largely viewed diet the same way for the last 100 years—assuming that there is one optimal diet. Now that we’ve identified that this is likely not the case, I think that in the future we will be able to identify the genetic factors involved in the varying responses to diet and use those to predict diet response in humans,” researcher William Barrington tells Psychology Today.

A team of researchers used four mouse strains to carry out the study. The animals served as represent models of genetic diversity. The animals have been given food equivalent to today’s Western diet, while others received a traditional Japanese diet, a traditional Mediterranean diet, or a high fat, low-carb Atkin’s-like ‘ketogenic’ diet. Other animals have received standard diet for comparison.

The scientists observed that the health-related response to each diet depended on the animals’ genetic strain. For instance, the western diet resulted in adverse health effects in one strain, but did not cause the same response in another. Some genetic strains have also prompted the animals to increase their calorie intake, thus rendering them obese. In contrast, some mice have remained obese despite carrying certain strains that prevented them from overeating.

“Given the metabolic and genetic similarity of humans and mice, it is highly likely that the level of diversity of diet response seen in our study will also be observed in humans. Since there are different optimal diets for different individuals, this underscores the need for precision nutrition, which would identify optimal dietary patterns for each person,” Barrington adds.

Sources include:

News.Cornell.edu

PsychologyToday.com