Researchers from the Washington University School of Medicine in St. Louis claim they have identified a variant of a gene called CD36, which is connected to the taste buds, and could mean that fat is sensed in the mouth in a similar way to other tastes – salt, sour, bitter, sweet, and umami. As many as one in five people may have a variant of the gene that makes less of an associated fat-sensitive protein, meaning that they could be less sensitive to the fat content of food.
They claim that this is the first time CD36 has been linked to fatty taste perception in humans, when traditionally fat perception was thought to be nearly entirely dependent on textural and aromatic cues.
“The ultimate goal is to understand how our perception of fat in food might influence what foods we eat and the quantities of fat that we consume,” said senior researcher Dr. Nada Abumrad of the Washington University School of Medicine. “In this study, we’ve found one potential reason for individual variability in how people sense fat.”
The researchers asked 21 obese subjects to taste the odd one out from three different solutions, one of which contained fat, and two others that were fat-free but similar in texture.
“This issue is particularly important in obesity, because obese subjects prefer foods with higher fat content and crave more high fat foods as compared with lean subjects,” the authors wrote.
They found that study subjects who made more of a CD36 protein were eight times more sensitive to fat content than those who made 50% as much of the protein.
Abumrad said that further research was necessary to determine whether ability to detect fat influences fat intake.
“It may be, as was shown recently, that as people consume more fat, they become less sensitive to it, requiring more intake for the same satisfaction,” Abumrad said.
Previous research in mice and rats has suggested that rodents without the CD36 gene no longer have a preference for fatty foods, and it may also play a role in their ability to digest fat properly.
Lead author Dr. M. Yanina Pepino said: “Diet can affect sensitivity to fat, and in animals, diet also influences the amount of CD36 that’s made. If we follow the results in animals, a high-fat diet would lead to less production of CD36, and that, in turn, could make a person less sensitive to fat. From our results in this study, we would hypothesize that people with obesity may make less of the CD36 protein. So it would seem logical that the amounts of the protein we make can be modified, both by a person’s genetics and by the diet they eat.”
Source: Journal of Lipid Research
Authors: Marta Yanina Pepino, Latisha Love-Gregory, Samuel Klein and Nada A. Abumrad