Should Fat Be Considered The Sixth 'Taste'?

At the end of the twentieth century, scientists had only identified four basic tastes that can be recognized universally by humans: sweet, sour, salty, and bitter. In recent years, umami has been added to the list (better known as the savory, meaty flavor of glutamates). Now, it looks like scientists might be adding a sixth category to our list of perceived tastes: fat. Our food is full of it, so why not have an entirely separate category for it in our lexicon of tastes, formerly known as the taste bud map? (Although now we know that perception of the five or six unique tastes is not limited to sections of the tongue).

According to a report in the Australian research journal, Flavour, fat does actually meet the criteria for a basic taste: it has a "distinct class of stimuli" (in this case, fats and fatty acids), the presence of receptors to change the chemical code in our brains and alert our senses to a new stimuli, as well as "perceptual independence" from the other five tastes. Meaning that, yes, the research team at Deakin University in Australia feels that fat tastes different from salt and umami, two tastes that are arguably pretty similar to fat.

"Whether there is a recognizable taste quality associated with fat is still up for debate, but there is no doubt that a fat taste quality is not equivalent to easily identified qualities such as sweet or salty," the researchers write in their report. Furthermore, this evidence for a "fatty taste," could actually link prevalence of obesity to addiction to that taste: "These data propose a direct role of the taste system in the consumption and preference of high-fat foods, which may be linked to the development of obesity given that differences in BMI have also been linked to oral fatty acid sensitivity."