University of Florida Study Reveals Loss In Sensory Perception May Not Be Linked To Aging

After six years of volunteers smelling lemons and some 40 other scents including natural gas and bubble gum, Dr. Marc Heft has determined that aging has little effect on smell, taste or touch.

"There is a belief that as you age, everything deteriorates. The truth is there is only a modest change in sensory functioning," said Heft, director of the Claude Pepper Center for Research on Oral Health in Aging at UF's College of Dentistry. "There are a number of older folks that can smell and taste just as well as many of the young."

Ruling out various factors, including disease and whether the participants were smokers, the researchers found less than 10 percent of the differences in sensory perceptions are age-related. Heft said the findings mean good news for older people, who are experiencing a higher quality of life and are living longer.

"In Florida alone there are more than a million people over the age of 75, and they are a fairly healthy, vivacious population," Heft said. "What's emerging is a more upbeat vision of aging." UF researchers recruited 180 healthy volunteers between the ages of 20 and 88 for the study. The researchers' goal was to look at normal changes in the senses of taste, touch and smell as a person ages. They also tested the volunteers' abilities to feel pain and tell differences in temperature.

The volunteers participated in five one-hour sessions to identify which stimuli they could perceive, their threshold level (the lowest amount of a stimulus a person could perceive and identify) and how well they perceived differences in sensations above their threshold level.

Using a probe about the size and shape of a pencil, the researchers asked the volunteers to identify various temperatures and pressures. The tests involved stimulating the area above the upper lip and the chin with the probe. "The face is a wonderful model to look at sensory perceptions because day to day we sample our environment through our nose, eyes and mouth," Heft said.

The researchers used a test known as the Pennsylvania Sme