London: It's long known that there are five basic tastes which the human tongue can detect -- sweet, sour, salty, bitter and savoury. Now, scientists say there exists a sixth one -- fat.

A team at Washington University in the US claims to have identified a potential chemical receptor for tasting fat, and also found that its sensitivity varies between individuals, the 'Journal of Lipid Research' reported.

The receptor is, in fact, located in the taste buds on the tongue which recognises fat molecules, say the scientists.

The finding may help to explain why some people consume more fatty foods, as they are less aware of the taste as they eat, and can be used to combat obesity by increasing people's sensitivity to fat in their food, the team says.

In their research, the scientists have showed that people with more of a receptor called CD36 were better at detecting the presence of fat in food. They found that variations in a gene that produces CD36 makes people more or less sensitive to the presence of fat.

The study found that those with half as much CD36 were eight times less sensitive to the presence of fat.

"The ultimate goal is to understand how our perception of fat in food might influence what foods we eat and the qualities of fat that we consume. We've found one potential reason for individual variability in how people sense fat.

"What we will need to determine in the future is whether our ability to detect fat in foods influences our fat intake, which clearly would have an impact on obesity," says Prof Nada Abumrad, who led the team.

Up to 20 per cent of people are believed to have a variant of the CD36 gene that is associated with producing lower levels of the receptor, which could mean they are less sensitive to the presence of fat in food. This may make them more prone to obesity.

Dr Yanina Pepino, a team member, added: "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 hypothesise 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."

(Agencies)