The first study to measure the full extent of age-related damage to all five senses — sight, hearing, touch, smell, and feel — found that 94 percent of all adults have at least one sensory deficit.

The study, which was conducted by researchers at the University of Chicago, found that 94 percent of people between the ages of 57 and 85 had at least one sensory deficit, 38 percent had two, and 28 percent had more than two.

Although some of the deficits were mild, 64 percent had at least one significant deficit, and 22 percent had at least two major deficits.

The most common sensory deficit, which affected 74 percent of the study's 3005 participants, was a decrease in the sense of taste. Twenty-six percent of the study subjects had a sense of taste rated only as fair, and 48 percent were rated poor.

Decreased sense of touch was also common. Thirty percent of study subjects had a normal sense of touch, but 38 percent were rated as fair and 32 percent as poor.

"We know that sensory impairment is common and is often a harbinger of serious health problems, such as cognitive decline or falls, as well as more subtle ones like burns, caused by loss of touch sensitivity, food poisoning that goes undetected because of loss of smell and taste, and smoke inhalation, from loss of smell," said study author Jayant Pinto, M.D.

"Our findings here give us a better appreciation of the prevalence of multi-sensory loss, a first step toward learning more about what causes the senses to decline," said Pinto.

The implications of sensory decline are wide-reaching. Several studies have linked hearing loss to mental decline and brain shrinkage, including a loss of memory and thinking skills. However, a recent study from the University of El Paso found that using hearing aids significantly improved cognitive function after only two weeks.

A study from the University of Florida, using the ability to smell peanut butter, linked a loss of smell with Alzheimer's disease.

An earlier study from Pinto's team found that a decrease in the sense of smell predicted mortality better than a diagnosis of heart failure or cancer. A similar study, published last September in JAMA Otolaryngology-Head & Neck Surgery, found that hearing impairment may also be associated with an increased risk of death.

"We need to understand the biology behind the links between age and sensory loss, and design better ways to prevent its decline," Pinto said. "People caring for older adults, including family members, caregivers and physicians, should pay close attention to impairments in vision, hearing, and smell."

Interventions to improve senses, such as eyeglasses and hearing aids, could make a big difference, said Pinto. "Even simple things like increasing spices in foods could help those with taste loss, or providing tactile clues for people with loss of touch could improve function."

The study was published in the Journal of the American Geriatrics Society.