The study – published in Obesity– investigated fat taste and preference in a group of overweight African-American adults, finding that those who had a specific genetic variation in the structure of a fat receptor known as CD36 perceived fat tastes differently.
The research team noted that those with a certain variation perceived the creaminess and fattiness of salad dressings quite well, but were less able to differentiate between high-fat and low-fat versions.
Despite this insensitivity to perception, people with the variation in CD36 reported that they liked added fats such as salad dressings, spreads, butter and margarine, more than those who did not have the genetic variation.
"This is the first time that a gene involved in fat taste has been linked to fat preference in humans," said Professor Beverly Tepper of Rutgers University, USA.
Designer fats and personalised diets?
The ability to taste fats provides important signals about the type of fat being consumed, and the implications of this new finding could be far reaching, suggested Tepper – a professor in the department of food science at Rutgers and co-author of the new study.
"We could use this information to design more healthful fats that also give foods the high sensory appeal that consumers want," she said.
"Using these two genetic markers, CD36 and PROP, we could identify those who are insensitive to oral fat and who may be more susceptible to high-fat diets and obesity," she added.
"We could devise more personalized diet strategies to address this specific dietary issue."
"CD36 is only the beginning," said Tepper. "There is at least one additional fatty acid receptor that is known to exist in humans, and probably others that have yet to be identified."
Tepper and her colleagues have been studying consumer preferences for high-fat versus low-fat foods for several years. She explained that the new study revealing a genetic link between taste perception and liking has is similar to previous reports from propylthiouracil (PROP)-tasting research on the TAS2R38 gene.
With this in mind, the new research focused on perception and preference for fat in people. Over a series of studies, the team asked participants to use their own words to describe dairy products that varied in fat content – such as ice cream, sour cream, whole milk and skimmed milk.
Super-tasters were found to use a rich and varied vocabulary to describe these foods, whereas non-tasters used very few, simple words.
"Even though the non-tasters had difficulty describing the foods, they knew what they liked, and they preferred the higher-fat products," said Tepper.
The researchers found that three variations in the CD36 gene “were associated with the outcomes.”
They said participants certain genotypes reported greater perceived creaminess, regardless of the fat concentration of salad dressings, and higher acceptance of added fats and oils compared to those with other genotypes. Tepper and her colleagues also found that BMI and waist circumference were higher in people with a certain variation of the gene which may have increased fat consumption.
“This is the first study to demonstrate an association between common variants in CD36 and fat ingestive behaviours in humans,” confirmed the researchers.
Published online ahead of print, doi: 10.1038/oby.2011.374
“Common Variants in the CD36 Gene Are Associated With Oral Fat Perception, Fat Preferences, and Obesity in African Americans”
Authors: K.L. Keller, L.C.H. Liang, J. Sakimura, D. May, C. van Belle, et al