Taste

There are thousands of taste buds on a person’s tongues as well as on the sides and roof of the mouth. Aging causes the taste buds to begin to disappear from the sides and roof of the mouth, leaving taste buds mostly on an individual’s tongue. The remaining taste buds eventually become less sensitive. These are called papillae, and there are four kinds of them: fungiform and filiform on the front half, and foliate and vallate on the back. The actual taste buds cluster together in packs of two to 250 within the papillae (Lembert, 2000).  The changes in an older person's sense of smell further changes the ability to taste foods. Taste buds decline with age with the ability to taste sweets declining first, followed by salty, then bitter, and last sour (Changes in Taste, 2009).

Sense of Smell

The sense of smell diminishes to some degree in aging individuals. The olfactory receptors are directly exposed to the outside environment, with their only protection of a thin layer of mucus, making them relatively susceptible to damage from such exogenous agents such as viruses, bacteria, pollutants, and airborne toxins. Moreover, since the axons of the olfactory receptor cells extend through the foramina of the cribriform plate to synapse within the olfactory bulb of the central nervous system (CNS), they are extremely vulnerable to shearing and tearing from movement of the brain relative to the cranium. Smell cells (along with taste cells) are the only sensory cells that are regularly replaced throughout a person's life span. There is an age-related decrease in the ability to identify or recognize different smells. And as an individual’s sense of smell diminishes, their ability to taste foods diminishes since smell enhances one’s ability to taste foods.