The 2000-10000 taste buds lining the tongue and parts of the mouth are receptors that predominantly only send one of 5 basic messages to the brain: salty, sour, bitter, sweet and umami, which is somewhat savory, and this is it. This is the human tongue, and just to point out, all taste sensations can arise from all regions of the tongue, that tongue map that you may have seen when you were little, with sweet in the front and sour on the sides, is a lie. Some areas can be more sensitive to some stimuli, but that old model is not correct. The point of this video, is that the taste buds, don’t do very much. Knowing something is sweet doesn’t give you flavour. Many fruits are sweet, but it’s difficult to tell them apart from that signal itself. So, flavour doesn’t come from the taste buds.
The 5 primary taste receptors are far outweighted by over 300 different smell receptors in our noses, which collectively can distinguish somewhere between 30,000 to a trillion different smells. It’s hard to give a precise number, but probably around 80 percent of the flavour in foods comes directly from our noses. We’re not tasting food, we’re smelling it. This, coupled with additional stimuli such as the appearance, sound (like a crunch), touch, spiciness, temperature, texture and the feel of food on our lips even further diminishes the importance of the taste buds for our enjoyment of a meal.
So, the taste bud’s role: sweet, salty, sour, umami and bitter, don’t really give flavour, but are predominantly for survival. Bitter and sour flavours deter us from eating toxic substances like rotten meat or anything spoiled or acidic. On the other hand, we’re enticed to eat sweet foods, as long as they’re not too salty, as these are usually quite nutritious in nature. New research suggests that perhaps we have senses for fat, metallic and carbonation tastes. But either way, that’s it. The taste buds don’t really add to the flavour or enjoyment that comes with eating. It’s been thought that we all lost only our sense of smell, the joy of food, regularly dining out to experience culinary delights, might largely disappear from society.
Taste buds do have their role and are even present elsewhere in the body. Throughout the airways, bladder, brain, testis, and the digestive tract they serve various purposes. For example, the taste bud for sugar, located in the intestinal tract, can induce the pancreas to release insulin. We don’t taste it that far down the system, but the receptor is there and doing its thing.
Because there’s so many receptors contributing to create flavour, our sense of this is not set. For example, it changes as we age. Some medications and activities such as smoking can affect how flavours are picked up. Additionally, they might make us less sensitive to ingredients; or leave a bitter, strange, or metallic taste in your mouth. Also, if your mouth is dry, flavours can’t dissolve as well in the saliva. Other changes can occur from infections or injuries, which could block the nose, or damage the nerves to it, changing the amount of flavour we perceive.
Even our digestive system doesn’t respond solely to the taste buds. A meal’s sight, sound, smell and touch all help to rise hunger hormone levels, get saliva flowing, and give that rumbling tummy. So next time you have a meal, be sure to enjoy the input from every sense, as your taste buds only play a minor role in the experience.