Seniors who want to gauge their own longevity might want to take a simple sniff test. Researchers at the University of Chicago found that older people with a lousy sense of smell were significantly more likely to be dead in five years than those who could easily detect common scents, reports the BBC. In their study, the scientists asked about 3,000 Americans ages 57 to 85 to identify five such scents: peppermint, fish, orange, rose, and leather. Researchers checked back in five years and discovered that 39% of people who got none or only one correct had died, reports LiveScience. In contrast, only 10% of those who got four or five right had died. As it turns out, a bad sense of smell was a bigger predictor of death than cancer, heart disease, or lung disease, reports WebMD.
"We think loss of the sense of smell is like the canary in the coal mine," says lead author Dr. Jayant Pinto of the University of Chicago at EurekAlert. "It doesn't directly cause death, but it's a harbinger—an early warning that something has gone badly wrong, that damage has been done." Among the theories: In order to have a good sense of smell, the body needs to constantly regenerate cells in the nose. And if that healthy regeneration isn't happening in the nose, it may not be happening elsewhere in the body, either. Researchers, however, don't want people to stress out if they flunk a homemade kitchen test. They might just have a minor sinus problem. (Scientists also have suggested that a smell test with peanut butter can help diagnose Alzheimer's.)