In one of the first large-scale studies of diet-related genes, researchers have found almost 500 genes that appear to directly affect the foods we eat. The findings represent an important step toward using a person’s genetics to develop precise nutritional strategies that help improve health or prevent disease.
Some genes we identified are associated with sensory pathways -; including those for taste, smell and texture -; and may also increase the reward response in the brain. Because some of these genes may have clear pathways to influence whether someone likes a food or not, they could potentially be used to create sensory genetic profiles to fine-tune a person’s dietary recommendations based on the foods they like to eat.
Joanne Cole, Ph.D., research team leader, Assistant Professor, Department of Biomedical Informatics, University of Colorado School of Medicine
For the study, the researchers used the UK Biobank, which contains data from 500,000 people, to perform the Phenomenology Association Study (PheWAS), which identifies genes that are more strongly associated with diet than with any other health or lifestyle factor. PheWAS studies are used to find associations between gene variants of interest and a range of human traits and behaviors, including dietary intake.
“The foods we choose to eat are largely influenced by environmental factors such as our culture, socioeconomic status and food availability,” Cole said. “Because genetics play 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 among environmental factors.” The data needed to do this was not available until recently.’
Cole will present the findings at NUTRITION 2023, the annual flagship meeting of the American Society for Nutrition, held July 22-25 in Boston.
One challenge in identifying diet-related genes is that what people eat correlates 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 understand the direct effects of genetic variants affecting diet and separate those from indirect effects, such as those where a gene affects diabetes and diabetes requires a person to eat less sugar.
This study design is possible because the UK Biobank contains not only in-depth genetic information but also detailed health and socio-economic data. This allowed the researchers to test individual genetic variants for associations with thousands of traits and then eliminate indirect gene variants that were more strongly associated with other factors, such as diabetes.
The analysis revealed about 300 genes directly linked to eating specific foods and almost 200 genes linked to dietary patterns that group different foods together -; for example total fish intake or fruit consumption.
“The study showed that dietary patterns tend to have more indirect genetic effects, meaning they are related to many other factors,” Cole said. “This shows how important it is not to study dietary patterns in a vacuum, as the impact of dietary pattern on human health may be completely mediated or confounded by other factors.”
In the short term, Cole is studying newly discovered diet-related genes to better understand their function, while 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 can improve adherence.
It may also be possible to use these new insights to tailor foods to a person’s genetic predisposition. “If we know that a gene encoding an olfactory receptor in the nose increases liking for fruit and enhances the reward response in the brain, then molecular studies of that receptor can be used to identify natural or synthetic compounds that bind to it,” Cole said. “We can then see if adding one of these compounds to healthy foods makes those foods more appealing to that person.”
source:
American Society for Nutrition