Older adults with a better sense of smell may live longer than those who have a poor sense of smell, a new study suggests. The study was a project of researchers in the United States that was continuing for over 13 years. They asked nearly 2300 men and women to recognize 12 common smells. All the subjects were from 71 to 82 years of age. The researchers gave the adults marks, from 0 to 12, based on how many smells they recognize correctly.
During the years of follow-up research, over 1200 of the adults died. When the study was started, none of the adults were weak. They could walk about half a kilometre, climb 10 steps and independently complete daily activities. In the latest findings, the researchers noted those with a weak nose were 30% more likely to die than people with a good sense of smell. The findings were reported last month in the scientific publication Annals of Internal Medicine.
Honglei Chen, a doctor with Michigan State University in East Lansing, Michigan, was the lead author of the report on the study. He said the connection between a poor sense of smell and an increased risk of dying was limited to adults who first reported good or excellent health. This suggests that a poor sense of smell is an early and sensitive sign of worsening health before it is recognizable in medical tests. With a poor sense of smell, people are more likely to die of brain and heart diseases, but not of cancer or breathing problems.
The results also suggest that a poor sense of smell may be an early warning of poor health in older age that goes beyond dementia (痴呆) or other neurodegenerative (神经变性的) diseases. These often signal the beginning of the weakening of the mind or body.
