Do you have a sweet tooth? It might come down to your DNA.
Researchers from the University of Colorado revealed almost 500 different genes that directly influence what we choose to eat, including those involved in our experience of taste.
"Dietary intake is influenced by an array of environmental factors, including socio-economic status, upbringing, culture, learned behavior, etc.," Joanne Cole, a professor in Genomics at the University of Colorado who led the research, told Newsweek. "However, there is a real genetic influence on the foods we choose to eat, albeit small.
"After identifying hundreds of regions in the genome that are associated with dietary intake, I sought to identify the genes that have direct influences on diet that are not mediated through another health, lifestyle, or environmental trait."
Several of the genes Cole identified were related to sensory pathways—those involved in taste, smell and texture.
One well-known example is the bitter taste receptor TAS2R38. This gene encodes a protein that interacts with a chemical found in brassicas, like Brussels sprouts and cabbages, that gives these foods their bitter taste.
"Some versions of these genes alter the lock-and-key binding of the receptor to flavor compounds, and this alteration in binding changes how our brains perceive flavor, and therefore, pleasure," Cole said.
In other words, some people are genetically hardwired to hate Brussels sprouts.
A similar mechanism might be behind why some people have a sweet tooth. "Some people might have a strong genetic preference for sweeter foods," Cole said. "I bet this is controlled by the binding of sugars to certain receptors in their sensory system, which then lights up the pleasure region in their brain."
Our DNA can also influence our preference for healthier foods.
"In my 2020 publication, I discovered two olfactory receptor genes influencing fruit intake," Cole said. "Individuals with the genotypes that increase fruit intake also reported less sugar consumption."
By improving our understanding of the genetic mechanisms that drive our dietary preferences, we may be able to trick our brains into opting for healthier food choices.
"We could develop binding compounds to these same sensory receptors that could modulate the brain's reaction," Cole said. "Flavor is the number one driver of food choice, so I would like to use this information to make healthier food more flavorful or personalize nutrition guidance based on sensory genetic and flavor profiles."
In the nearer term, these results could be used to develop personalized dietary recommendations for an individual based on their genetic profile and the foods they like to eat, making it easier to stick to a healthy diet.
Cole will present these findings at NUTRITION 2023, the annual flagship meeting of the American Society for Nutrition on July 22.
