Loss of smell could be an early sign of Alzheimer’s
It happens to most of us: Our sense of smell decreases as we grow older. But a new study has found that black folks have a much greater decline in their sense of smell than their white counterparts. Though it sounds like a minor thing, it can lead to serious consequences. Olfactory loss often leads to poor nutrition. Worse: It also may be an early warning sign of Alzheimer’s or Parkinson’s.
The study, from the Journal of Gerontology: Medical Sciences, found that as they aged, African Americans and Hispanics suffered similar deficits to their sense of smell. For Hispanics, social and cultural factors (disparities in education and income and health-related cognitive problems) accounted for the sensory loss. But for African Americans premature presbyosmia (the formal name for age-related declines in the ability to smell) couldn’t be explained solely by social, environmental or medical factors.
“We have long known that men begin to lose their sense of smell some years sooner than women, but this is the first study to point to racial or ethnic differences,” said study author Jayant Pinto, M.D., associate professor of surgery at the University of Chicago. “What surprised us was the magnitude of the difference. The racial disparity was almost twice as large as the well-documented difference between men and women.”
According to the National Institute on Aging, many people live long lives with only minor age-related declines in the ability to smell, but about 24 percent of Americans 55 and older have a measurable problem with their sense of smell. That number increases to about 30 percent for those ages 70 to 80, and to more than 60 percent after age 80.
In the study researchers found:
Half (49 percent) of those tested identified five out of five odors (peppermint, fish, orange, rose, leather); 78 percent got four or more right, 92 percent got at least three and 97 percent got two or more correct.
Performance declined as age increased; 64 percent of those age 57 identified all five, but that fell to 25 percent of those age 85.
Non-white subjects scored 47 percent lower.
According to Pinto, black and Hispanic women start experiencing loss of smell in their mid-60s. For minority men, the decline can begin as early as their late 50s. White women don’t experience similar loss until their early 70s, and white men start about five years earlier.
Reasons for the disparity are not clear, but the study’s authors suspect genetic variation, medications, chronic nasal disease or exposure to toxic chemicals could be culprits. “Sanitation workers, for example, are often affected,” Pinto noted. “They are routinely exposed to noxious odors that can trigger inflammation.”
Not being able to smell can impact health in a negative way. People with a reduced ability to smell often are unable to stay on top of personal hygiene. They may not enjoy eating as much. And their lives could be at risk. “They make poor food choices [and] get less nutrition,” Pinto said. “They can’t tell when foods have spoiled or detect odors that signal danger, like a gas leak or smoke.”