Taste Bud Evolution

Imagine you’re at a family reunion. You look at the dinner table and see the menu for that day: salad. Your grandparents are happily munching away—whether it’s the tomatoes, broccoli, or celery, they seem to be enjoying their food. On the other side of the table, you see your baby cousin struggling to mouth a single piece of lettuce. Though most might dismiss the baby’s reluctance to eat vegetables as childish immaturity, science proves that there is an alternative reason: taste buds. 

Taste buds lie on your tongue and allow you to evaluate food based on five categories: sweetness, bitterness, sourness, saltiness, and deliciousness. They are enclosed in the bumps on the surface of your tongue called papillae, which also grip your food when it’s in your mouth. Contrary to popular belief, taste buds are not specifically sectioned in the mouth. Instead, they are equally distributed all across the surface, allowing for maximum absorption. 

Taste buds contain microvilli, which are membranes that are shaped like a finger; they’re used to relay messages to the brain any time it is in contact with a substance through neurotransmitters, which are chemical messengers that transmit impulses in neurons. The transmitters involved with your taste buds are adenosine triphosphate, acetylcholine, serotonin, norepinephrine, and γ-Aminobutyric acid. These neurotransmitters send impulses from the papillae in your tongue to the brain to signal how the substance tastes. Meanwhile, the nose contains receptors called olfactory receptors which allow the nose to detect and recognize specific scents and flavors outside of the five basic tastes. Combining these two processes allows the brain to identify the food and determine whether the consumer likes it.

On average, an infant is born with 30,000 taste buds. Having this many taste buds means children are affected by taste much more than adults because they have more neurotransmitters that will relay more messages to the brain. However, by the time adulthood is reached, that number depletes to 10,000. Women typically start to lose their taste buds rapidly starting at the age of 40 and men at 50. This is because age causes the body to reproduce taste buds at a much slower rate, meaning taste buds deplenish faster than they regenerate. With less taste buds, adults are less prone to the exaggerated five basic tastes that children experience, which also means they have a harder time detecting dangerous substances entering the mouth. Salty and sweet tastes are usually the first to weaken, and sourness and bitterness quickly follow. This is why children are statistically less likely to enjoy vegetables; the bitterness is much stronger to them than it is to adults. 

Research conducted in Kagome Co Ltd involved surveying a group of 800 children, ages ranging from three to 15, in Japan. Out of this group, 32.5 percent voted the eggplant as the vegetable they dislike the most. That was followed by bell peppers with 26 percent, then shiitake mushrooms, okra, and onions—vegetables considered bitter in taste. Meanwhile, children in this survey voted in favor of vegetables that they enjoyed eating the most, namely sweeter vegetables such as corn and soybeans. These results indicate that children may be more acutely aware of the taste differences between sweeter vegetables and more bitter vegetables.

Though age is typically the greatest factor to decreasing taste buds, aging is not the only way to lose them. Research proves that vaping can lead to lack of taste: when vape juice ingredients like propylene glycol, ethylene glycol, and vegetable glycerin contact your tongue, taste buds are dehydrated and essentially blocked off from the taste of foods. In addition, using tobacco products, specifically chewing tobacco, can cause your taste buds to incorrectly identify the taste of certain foods. Also, using cigarettes obliterates taste by exposing your nose pathways to harmful substances and desensitizing them. In the most extreme cases, a person is at higher risk of developing nasal polyps. Nasal polyps are growths that appear on the sinuses of your nose, and, though painless, can block nose airways that are essential to breathe. This hinders your sense of smell, which, as mentioned before, is critical in perceiving taste. 

Being able to enjoy the taste of nutritious foods is one of life’s greatest joys. Unfortunately, taste buds don't last forever. However, that doesn’t mean that being young guarantees more taste buds either—the health choices that you make in your life can diminish taste buds at a faster rate. Though losing taste buds through age isn’t entirely preventable, refraining from engaging in harmful substances is a precaution that everyone can and should take.