Aging is generally a state of constant change, and it is often change that we aren’t comfortable with. When we think of aging, we most often associate it with a loss of physical or cognitive ability, but the dulling of senses such as taste and smell is another difficult aspect of aging to deal with.
This loss of taste and smell tends to happen naturally after the age of 60 for men and after 50 for women, but this is not to say that these diminished senses are caused solely by aging. Other contributing factors may include allergies, dental problems, certain kinds of medication, injuries to the face or head, stroke and as an effect of Parkinson’s or Alzheimer’s disease progression.
Losing these senses may be accompanied by a loss of appetite and therefore, poor nutritional habits such as using more salt or sugar in order to taste things. It can also contribute to depression if severe enough.
Sometimes the cause of the diminished senses can be treated, but age-related loss of taste and smell is unfortunately permanent. The two senses are tied together as most tastes are linked to an odor. Taste buds on the tongue actually only detect certain flavors, but our noses pick up thousands of smells that are related to the ability to detect the tastes we associate with certain foods.
With any sense, a certain amount of stimulus is required in order for you to become aware of it. The moment you do is typically known as the “threshold” and as we age, the amount of stimulation required to reach the threshold becomes greater.
What Happens to Taste?
Taste buds tend to shrink and decrease in number as we age. In addition, we tend to produce less saliva as we age, which can cause dry mouth and impact our ability to taste things.
The average person has more than 4,000 taste buds. While they are most commonly associated with our tongues, taste buds can be found in other areas such as the roof of the mouth, the esophagus and the throat. They sense the five categories of flavor: sweet, salty, sour, bitter and “umami” or savory flavors.
Taste buds generally experience cell turnover at a fast pace, experiencing regeneration roughly every 10 days. But as we age, the cells aren’t replaced at the same rate. This is coupled with a breakdown of the cell membranes that transmit taste information from the taste bud to the brain.
What Happens to Smell?
Smell is one of our most important senses, alerting us to danger such as fire, gas leaks or foods that could make us sick.
THE SENSORY SYSTEM
A loss of smell can be tied to a loss function in nerve endings and diminished mucus production in the nose. Mucus is essential in odor detection, helping the scent remain in the nose so it can be detected by nerve endings. Eventually, mucus also helps cleanse odors from the nerve endings.
Like the cells which transmit taste information, cells in our noses which do the same for smell don’t regenerate as easily with age. They can also be damaged by external factors over time, such as air pollution or smoking. Older adults who have suffered a stroke or who are epileptic often experience an impaired sense of smell.