Scientists agree on five basic tastes we recognize in our food and beverages: sweet, salty, sour, bitter and umami. Now they might have to accept a sixth basic taste, which until now only had been considered playing a role in food texture: Fat has taste…!

Nutritionists and other scientists have said for years that fat only provides texture to food, and that pure fat itself doesn’t have any taste. Fat has been thought to be a flavour carrier delivering taste and odour compounds derived from different parts of food, and as a component that provides texture called “mouth feel” by food scientists.

However, the research done by Richard Mattes, professor of foods and nutrition at Purdue University Indianapolis, suggests that we are indeed able to taste fat.

The first one who proposed that humans could taste fat was the French physician and philosopher Jean Fernell in the 1500s. As a sense for fat detection remained unknown, modern scientists didn’t believe this was possible. Recent studies with rats began to cast doubt on this theory, when the results showed that rats easily detect food with fat and prefer it to “light” alternatives.

Previous studies by Mattes had shown that blood fat levels were changed in humans just by putting fat into their mouths. Consequently he took the blood fat level as a marker for fat detection in further studies.
The objective of his following research was to determine weather humans were able to smell or to taste fat, or both. Therefore he offered fat cream cheese to two different groups of test persons. One group could smell and test the cheese, the other group wore nose plugs, and could only taste the cheese. Measuring the blood fat levels of the test persons, the results were compared to a group that received no sensory stimulation at all.

The study revealed, that blood fat levels in the group that could taste and smell, were three times higher than in the control group. However, the study also proved that blood levels rose as much in the group that wore nose plugs. Blood fat levels didn’t rise in the control group.

“This tells us that taste is the stimulus that causes the rise in blood fat levels. The taste, and not the smell, is what the body is responding to,” Mattes says. “I wonder if the less-than-perfect performance of current fat replacers may be due to a lack of understanding of all mechanisms for fat perception.”

Regarding evolution, the ability to taste fat might have given a similar advantage like the umami called taste, which detects protein-rich foods through monosodium glutamate. At times when our ancestors were still hunting and searching for food, instead of going to the shop, protein-rich and fat food both presented an indispensable source of energy, probably giving evolutionary advantages.

Those days are gone, but discovering the importance of fat in our taste perception and food appreciation, might explain why fat-free foods aren’t as popular as full-fat versions. This might change the world of nutrition and diet products…