How many tastes can we taste?

Sofia Miettinen

Taste is a sensation that happens when food causes a chemical reaction with receptors on taste cells. Most taste cells are found on your taste buds on your tongue; your tongue has between 2000 and 4000 taste buds and each taste bud has up to 100 taste cells. But taste cells can also be found on the roof of your mouth, your throat and down your oesophagus (food pipe)! You cannot taste with your lips, the underside of your tongue or with your cheeks.

 

Scientists disagree exactly how many tastes there are, but it is mostly agreed that there are five basic tastes: sweet, salty, bitter, sour and umami (savoury). Some scientists suggest that fat, starch, calcium, hot or coolness are also tastes.

 

You may have heard that the tongue has a ‘taste map’ and detects different tastes in different zones of the tongue, but this is not true. Each taste cell on your tongue has lots of receptors so it can detect all the basic tastes, but only one type of taste is detected at any time.

 

Food is chewed and some of it is dissolved into saliva and pre-digested by enzymes in the mouth such as amylase, lipase, and protease. The digested food binds to receptors in the taste cells, which causes a chain of events that sends signals via nerves of the brain called cranial nerves to the gustatory (taste) centre of the brain. A nerve called the facial nerve carries taste from the front 2/3rds of the tongue, whereas the glossopharyngeal nerve senses the back 1/3rd. The vagus nerve carries information from the back of the throat.

 

Flavours happen from the combination of taste, smell, and the detection of texture and temperature.

 

Your taste cells can detect bitter the easiest and only need very small amounts to sense it, whereas salty and sweet foods are more difficult to detect. Scientists have found that only 25% of people detect an extremely bitter taste with phenylthiocarbamide, a chemical that tastes very bitter to some people but tasteless to others. Your genes decide how much or little of each chemical you need to be able to taste it, which is why some people can be supertasters. Scientists have found that supertasters may be less likely to enjoy eating brussels sprouts, cabbage, coffee and even carbonated water! Your ability to detect taste gets worse with age due to a combination of factor such as your taste buds becoming less sensitive, your sense of smell worsening, and producing less saliva; older adults need to add more salt, spices, and sugar to foods to taste them compared to children.

 

Some people can have problems with their taste, and this may be due to smoking, trauma of their brain, older age, vitamin deficiencies and certain medications such as some antibiotics or antidepressants. Some people can even have no taste at all, called ageusia (a-gew-zee-a). Babies experience their first tastes before they are born through amniotic fluid, the fluid they swim in inside the mother’s womb. Scientists have found that babies during pregnancy react to different foods their mother is eating, and this can influence their taste preferences once they are born.

 

Animals taste things differently to humans; butterflies and crabs have taste cells on their feet and octopuses can taste with the suckers on their tentacles, and cats are unable to taste sweetness! Snakes are clever and use their tongues to “taste” their prey from far away!