94 Percent of Adults Will Lose at Least One of Five Senses, but Often More

Loss of taste is common in aging adults. Michaela Rehle/Reuters

Most people, as they age, must come terms with the fact that they'll need to buy reading glasses or have become hard of hearing. However, most don't consider that all five senses—sight, hearing, smell, taste and touch—can be compromised by aging. A new study published Thursday in the Journal of the American Geriatrics Society suggests multi-sensory loss is very common in older adults. As much as 94 percent experience a loss of at least one sense or more.

Researchers at the University of Chicago looked at data from the National Social Life, Health, and Aging Project, a population-based study of U.S. adults aged 57 to 85. Out of the 3,000 people in the study, 64 percent had at least one sensory deficit, 38 percent had two, and 28 percent had three, four or even five.

Only a quarter of the participants had a sense of taste that could be categorized as "fair," while nearly half had a sense of taste rated "poor." Dr. Jayant Pinto, associate professor of surgery at the University of Chicago and a co-author of the study, says many physicians underestimate the dangers that can come with loss of taste, including reduced nutrition or consuming spoiled food, both of which can make a person seriously ill. (In addition, a loss of the taste sense likely means a decline in the sense of smell, since much of what we identify as the experience of eating is part of olfactory processing.)

A handful of studies have explored how aging affects sensory loss, but Pinto says he and his team are the first to track the decline of all five senses together. This study is also the first to examine how sensory impairment of all five senses affects different demographics in an aging population. The study found African-Americans scored lower in measurements than the average person in four of the five senses (they tended to have better than normal hearing, though). Hispanic subjects were more likely to have diminished senses of sight, touch and smell but scored higher on taste.

"Certain populations age faster than other populations, and this is a manifestation of that," says Pinto. However, he says this is only part of the picture. He suggests a lifetime of limited access to health care services may be another contributing factor in why certain ethnic groups are more likely to lose more senses. Lifestyle and environmental factors can also figure into sensory decline. For example, years of attending loud concerts can dull one's sense of hearing, and some research suggests air pollution affects our sense of smell.

This research is also helpful for understanding of why people are more likely to experience a lower quality of life as they age, and how things like the right glasses, hearing aids or smell training can alter a person's everyday experience in positive ways, according to Pinto. "Even small things can make a big difference in an older adult's life," he says.