06/16/2010 09:16 am ET | Updated Nov 17, 2011

Mouth Health: Your Taste Buds Explained

It's likely you just attended a holiday-weekend barbecue. And all kinds of good "summery" food and drink were probably served. Mmmm... cheeseburgers.

But what makes that food so good? Your taste buds, of course!

Did you ever really stop to think about the taste of the last good meal that you had? Was it salty? Was it sweet? Was it sour, or perhaps bitter? Or was it a combination of these sensations? While it's unlikely that we ever put too much thought into the number of meals that we eat each day, no meal would be much of an experience at all if it were not for our taste buds.

Taste buds are part of our five major sensory perceptions (see, hear, smell, touch and taste) that allow us to differentiate the flavors found in our food. While taste is recognized as the weakest of the five senses, it still plays an important role in how we enjoy food. Taste buds are generally recognized as the small raised bumps on the top of a person's tongue, which are called papillae. These papillae have small hairs called microvilli that tell a person's brain how to interpret individual flavors. Without these microvilli, everything we eat would taste the same.

But how can the taste buds on a tongue tell the difference in a flavor? The answer can lead to some entertaining experimentation.

Each part of the tongue registers a different taste sensation. For example, the taste buds on the tip of a person's tongue register salty and sweet flavors. The sides of the tongue can detect sour flavors, and the back of the tongue picks up the bitter flavors.

Some people believe that there is also a fifth taste called "umami," which is a difficult to describe taste that doesn't fall under the other four classifications. This particular flavor is said to combine with other flavors, making existing tastes more rich and intense. While the concept of a "fifth taste" is somewhat controversial in nature, Asian cooking seems more receptive to this concept.

The tongue is not the only factor in processing the flavors we perceive. The nose also plays an integral part in allowing a person's brain to recognize what is being eaten. As people chew their food, chemicals are released from the food that travel into the nasal passage, triggering the olfactory receptors to work with the tongue to decipher the "true" flavor of what a specific food should taste like. In fact, holding your nose while eating will throw off the sense of taste somewhat, as the tongue's taste buds will not be able to process the actual flavor until the nasal passages are free again.

What people may not realize, however, is that the tongue is not the only place that houses taste buds. These taste buds can not only be found on the roof of a person's mouth, but to a lesser extent, the lips, cheeks and back of the mouth. Similar to how the taste of food can be thrown off by closing off the nose, a person will notice the difference in taste without these sensory areas when one of these taste zones are accidentally burned by a piece of food that is too hot.

But there's no reason for alarm: Even on those unfortunate "burned mouth days," an average person has plenty of taste buds to spare, with a tongue potentially having eight to 10,000 sensory bumps. Those taste buds get replaced with new ones about every two weeks.

That's not to imply that our broad sense of taste lasts forever. As we get older, people lose the ability to detect tastes on the roof and sides of the mouth. The taste buds will drop to the "2,000 - 5,000" range, and will largely just remain on a person's tongue. There is some consolation, however: As the number of taste buds decrease, so does the sensitivity to certain types of foods. That means certain types of foods once considered "too strong" when a person was younger may be more palatable. It's like getting a whole new menu of foods to try (this would also likely explain an adult's tolerance of broccoli!)

Age is not the only means in which a person's taste buds can be diminished. Smoking, poor dental hygiene, lack of vitamins and certain medications can throw a person's sense of taste off. Physical and chemical changes also have an effect. Illnesses such as mouth ulcers or acid reflux can cause variations in taste, and unsafe exposure to chemicals or radiation can have long-term effects. Even gender plays a part in the number of taste buds, as females generally have more taste buds than men.

While age-related loss of taste is irreversible, external factors such as treatment of illnesses and quitting smoking can make a notable difference in restoring a person's sense of taste. In fact, many smokers who have quit report a marked increase in taste.

While the utilization of a person's sense of taste is a common everyday occurrence, it's impressive to think of the amount of cooperation between the olfactory receptors of the nose and the myriad of taste buds in the mouth, which combine to create the perfect-tasting meal for us.

Until next time, keep smiling!