The Science Behind What We Taste
Most of us grew up believing there were just four basic tastes – sweet, sour, salty, and bitter. But then came umami in the early 2000s, that savory fifth taste that makes your mouth water when you bite into a piece of cheese or a perfectly grilled steak. Now scientists are throwing another curveball: they’re saying fat might actually be the sixth basic taste, not just a texture we feel in our mouths. Think about it – when you bite into a piece of bacon or taste olive oil, there’s something distinctly different about how your tongue responds compared to just feeling the creaminess or oiliness.
Meet Oleogustus – The Unpleasant Truth About Fat Taste
The researchers proposed “oleogustus” as a way to refer to the sensation. “Oleo” is a Latin root word for oily or fatty and “gustus” refers to taste. But here’s the kicker – the taste of fat, which researchers call “oleogustus” (a combination of the Latin terms for oil and taste), is a distinct flavor and, as a new study in the journal Chemical Senses reports, quite unpleasant. Fatty taste itself is not pleasant. When concentrations of fatty acids are high in a food it is typically rejected, as would be the case when a food is rancid. In this instance, the fat taste sensation is a warning to not eat the item. At the same time, low concentrations of fatty acids in food may add to their appeal just like unpleasant bitter chemicals can enhance the pleasantness of foods like chocolate, coffee and wine.
The Purdue Breakthrough That Changed Everything
Fat should be considered the sixth taste and can be called oleogustus, according to a study from Purdue University. The research team at Purdue University conducted a groundbreaking study that might have changed how we think about taste forever. In a study done by Purdue University, 102 participants were given numerous cups containing mixtures that each tasted sweet, salty, bitter, sour, umami or fatty, and they were asked to group them together based on similar flavours. Texture, odour and appearances were all controlled for. The participants were able to distinguish sweet, salty and sour flavours with ease, but when it came down to the fatty mixtures, they initially classified them as being bitter due to the unpleasant taste. Later, when they were asked to group together bitter, umami and fatty samples, the participants grouped the fatty flavours together and were able to distinguish them as being separate from the rest.
Why Fat Doesn’t Taste Like You Think It Does
Most of the fat we eat is in the form of triglycerides, which are molecules comprised of three fatty acids. Triglycerides often impart appealing textures to foods like creaminess. However, triglycerides are not a taste stimulus. Fatty acids that are cleaved off the triglyceride in the food or during chewing in the mouth stimulate the sensation of fat. This explains why butter tastes creamy but rancid oil tastes terrible – it’s all about those free fatty acids breaking loose. While most people have a hard time describing the taste of fat, they’re still able to tell that it’s different from the basic flavours. However, our conscious perception of oleogustus isn’t quite the same. When we eat something salty, we instantly identify it as saltiness, but with fatty acids, we don’t have the same instant perception.
The Molecular Machinery Behind Fat Detection
Scientists have identified specific receptors in our taste buds that respond to fatty acids. Emerging evidence suggests that CD36 and G protein-coupled receptor (GPCR) 120 are the most likely candidate receptors on taste bud cells (TBC), with multiple taste transduction mechanisms also involved. CD36 and GPR120 have nonoverlapping roles in TBC signaling during orogustatory perception of dietary lipids; these are differentially regulated by obesity. Think of these receptors like specialized locks that only fatty acid “keys” can open. When they do, they send signals to your brain saying “hey, there’s fat here!” The two G-protein coupled receptors GPR40 (Ffar1) and GPR120 are activated by medium and long chain fatty acids. Here we show that GPR120 and GPR40 are expressed in the taste buds, mainly in type II and type I cells, respectively. Compared with wild-type mice, male and female GPR120 knock-out and GPR40 knock-out mice show a diminished preference for linoleic acid and oleic acid, and diminished taste nerve responses to several fatty acids. These results show that GPR40 and GPR120 mediate the taste of fatty acids.
The Five Criteria That Make a True Taste
To be considered a basic taste, a flavour must meet five criteria. First, there must be a chemical stimulus, which then activates specific receptors on our taste buds. The chemical signal must travel from the receptors to the brain, and the brain must be able to identify and process the taste. Finally, the entire process has to trigger physiological effects on the rest of the body. Therefore, overall, with the exception of an independent perception, there is consistent emerging evidence that fat is the sixth taste primary. It’s like a scientific checklist that fatty acids seem to tick off one by one, though that perception part is still giving researchers headaches.
When Your Body Gets Confused About Fat
Obese mice had decreased spontaneous preference for fat. Fungiform TBC from obese mice had reduced Ca(2+) and serotonin responses, but increased release of glucagon-like peptide-1, along with reduced levels of CD36 and increased levels of GPR120 in lipid rafts. This research suggests that people who are overweight might have trouble tasting fat properly, which could create a vicious cycle. The spontaneous preference for dietary lipids is principally regulated by 2 lingual fat taste receptors, CD36 and GPR120. Obese animals and most of human subjects exhibit low orosensory perception of dietary fat because of malfunctioning of these taste receptors. It’s like having a broken smoke detector – if you can’t taste fat properly, you might end up eating more of it without realizing it.
The Evolutionary Advantage of Tasting Fat
The fact that energy-dense foods are attractive, and thus preferentially consumed, might constitute an advantage inherited from evolution to survive a food scarcity. Together, these observations suggest the existence of an early and selective detection of these caloric nutrients. From an evolutionary perspective, being able to detect fat made perfect sense for our ancestors. High-fat foods provided crucial energy for survival during lean times. The intake and regulation of dietary fats is considered especially important in the development of overweight and obesity, given their high energy density and palatability alongside their ability to promote excess energy intake. The intake and regulation of fats in the obese state appears especially problematic given that obese persons prefer higher fat foods that represent significant portions of the obese diet.
The Historical Perspective Nobody Talks About
Fat has been classified as a taste as early as 330 BC by Aristotle and many other academics over the centuries. More recently, fat has been associated with texture, flavour release and thermal properties in foods, but not the sense of taste. It’s fascinating that ancient philosophers were onto something that modern science is just now catching up with. For centuries, we’ve dismissed fat as just a texture or mouthfeel, but maybe our ancestors had it right all along. The debate isn’t entirely new – it’s just that we now have the technology to actually prove what people have been sensing for millennia.
The Genetic Lottery of Fat Perception
Studies in adults and children of various ethnicities have demonstrated that both lifestyle and genetic factors may contribute to fat taste sensitivity (FTS). We report that FTS differed in individuals with differing genotypes; genotypes that have previously been associated with differences in dietary intake. Specifically, FTS was lower in rs1514175 Troponin I-Interacting Protein Kinase (TNNI3K) gene AA/AG genotype and was higher in rs6265 Brain Derived Neurotrophic Factor (BDNF) gene TT/CT genotype. Your ability to taste fat might actually be written in your DNA. Some people are naturally better at detecting fatty acids than others, which could explain why some folks can immediately tell when olive oil has gone bad while others remain completely oblivious.
The Skeptics and Their Valid Concerns
There is debate regarding fat taste as an independent taste, specifically relating to taste receptor functionality, the type of fatty acid required to elicit a taste response and the additive nature of such a response. The brain’s ability to perceive fat is still a debatable topic, as more evidence is needed to determine if fat is actually distinct enough by itself. So far, researchers are going the extra mile by studying the genetics behind the taste of fat. Not everyone in the scientific community is convinced that fat deserves its own spot at the taste table. Some argue that what we’re experiencing is just a combination of other tastes and sensations rather than a truly independent sixth taste.
What This Means for Food and Health
Identification of this new taste could provide insight into ways to fight obesity and how to develop food products to optimize health. By building a lexicon around fat and understanding its identity as a taste, it could help the food industry develop better tasting products. If fat really is a distinct taste, this discovery could revolutionize how we approach nutrition and food development. Imagine being able to enhance the fat taste in healthier foods, making them more satisfying without actually adding more calories. These findings, which highlight the role played by CD36 in the oro-sensory perception of dietary lipids, raise the possibility of novel pharmacological strategies to modify attraction for fatty foods and decrease obesity risks.
