In one of the first large-scale studies of diet-related genes, researchers have discovered nearly 500 genes that appear to directly influence the food we eat. The findings represent an important step toward using a person's genetics to develop precision nutrition strategies that help improve health or prevent disease.
"Some of the genes we have identified are related to sensory pathways, including those for taste, smell and texture, and may also increase the reward response in the brain," explains lead research team Dr Joanne Cole. , Associate Professor, Department of Biomedical Informatics, University of Colorado School of Medicine, USA "Since some of these genes may have clear pathways to influence whether or not someone likes a food, they could potentially be used to create sensory genetic profiles to refine a person's dietary recommendations based on the foods they like to eat."
For the study, presented at NUTRITION 2023, the annual meeting of the American Nutrition Society, the researchers used the UK Biobank, which contains data from 500,000 people, to perform a phenotype-wide association study (PheWAS) that identified genes more strongly associated with diet than with any health or lifestyle factor. PheWAS studies are used to find associations between genetic variants of interest and a spectrum of human traits and behaviors, including dietary intake.
"The foods we choose are largely influenced by environmental factors such as culture, socioeconomic status, and food accessibility," Cole explains. Since genetics plays a much smaller role in influencing dietary intake than all environmental factors, "we need to study hundreds of thousands of individuals to detect genetic influences amidst environmental factors. The data needed to do so have not been available. been available until recently.
One of the challenges in identifying diet-related genes is that what people eat is correlated with many other factors, including health factors such as high cholesterol or body weight, and even socioeconomic status. In the new work, the researchers applied computational methods to determine the direct effects of genetic variants on diet and separate them from indirect effects, such as when a gene influences diabetes and the person has to eat less sugar.
This study design was possible because the UK Biobank contains not only detailed genetic information, but also detailed health and socioeconomic data. This allowed the researchers to analyze individual genetic variants for associations with thousands of traits, and then eliminate indirect genetic variants that were more strongly associated with other factors, such as diabetes.
The analysis revealed some 300 genes directly associated with the consumption of specific foods and almost 200 genes linked to dietary patterns that group multiple foods together, for example, the general intake of fish or the consumption of fruit.
"The study showed that dietary patterns tend to have more indirect genetic effects, which means they are correlated with many other factors," Cole said. This shows how important it is not to study dietary patterns in a vacuum, because the impact of the pattern diet on human health may be completely mediated or confounded by other factors".
In the near term, Cole is studying the newly identified diet-related genes to better understand their function, while also working to identify even more genes that directly influence food preferences. She would like to pursue several lines of translational research based on these findings. For example, she is interested in studying whether using a person's genetics to tailor the taste profile of a diet designed for weight loss could improve adherence.
It would also be possible to use this new knowledge to tailor food to a person's genetic predisposition. "If we know that a gene encoding an olfactory receptor in the nose enhances fruit liking and enhances the reward response in the brain, molecular studies of this receptor could help identify natural or synthetic compounds that bind to it - he explains, "Then we could see if adding one of those compounds to healthy foods makes those foods more palatable to that person."
