Diet + Genetics: What’s the Connection?

By: Amanda Belo

You are what you eat may be true in more ways than one. Based on animal research models, the same diet approach may affect each person differently based on their genetics.  Texas A & M University Health Science Center recently performed a study on the ways in which diet affects different genetic types. Researchers conducted the study using mice since they are “similar to humans in genetic composition + propensity to develop a metabolic disease, but enable precise genetic and environmental control.”1

The Study:

Over six months, the study tested how four different mouse strains would react with five different human diets: an American-based diet, high in fat and refined carbs; a Mediterranean-based diet, with wheat and red wine extract; a Japanese-based diet, with rice and green tea extract; and, a Maasai/ ketogenic-based diet, high in fat and protein with few carbs. The American diet is perceived as negative or unhealthy, while the Mediterranean, Japanese and ketogenic diets are associated with being healthy. The study’s control group was fed a standard commercial mouse diet.

For the different mouse strains– A, B6, FVB and NOD – the genetics between groups would be similar to the differences found between any two unrelated people.

The Results:

The study found that no single diet affected all of the genetic groups in exactly the same way. Further, no single diet improved health for every mouse strain. Researchers measured physical outcomes – such as evidence of conditions that increase the risk of severe health conditions, like heart disease and diabetes – and behavioral differences to compare how each diet impacted each strain. The following are the results of which diet outside of the American diet improved overall metabolic health for each strain:

  • Mediterranean: FVB (improved lipid profile), B6 (improved glucose metabolism)
  • Japanese: B6 (improved body composition, glucose metabolism), FVB (improved body composition, liver health), NOD (improved body composition, liver health)
  • Ketogenic/Maasai: A (improved body composition, blood lipid profile), B6 (improved body composition, blood lipid profile, glucose metabolism)

The American-based diet was generally the most unhealthy for all genetic types, causing various levels of metabolic syndromes like increased body fat and LDL cholesterol levels.


What it Means:

Following the health trend of personalized fitness and nutrition, this study makes a case for how beneficial and effective it can be to make health recommendations based on the individual rather than focusing on a one-size-fits-all approach.  “Dietary advice, whether it comes from the United States government or some other organization, tends to be based on the theory that there is going to be one diet that will help everyone,” said David Threadgill, PhD, with the Texas A&M College of Medicine and College of Veterinary Medicine & Biomedical Sciences and senior author of the study. Based on the current obesity epidemic, it seems these guidelines have failed to have a positive effect.

The research team will look towards future work determining which genes are involved in the response to each diet.





*Before making any dietary changes, please consult with your primary healthcare provider.



  2. Vital Record