Strong Sense of Smell May Be Linked to Longer Life
Older adults with a poor sense of smell may die sooner than those who have a better sense of smell, a new study suggests.
The study was a project of researchers in the United States that was ongoing for over 13 years. They asked nearly 2,300 men and women to identify 12 common smells. All the subjects were from 71 to 82 years of age.
The researchers gave the adults scores, from zero to as high as 12, based on how many smells they identified correctly.
During 13 years of follow-up investigation, over 1,200 of the subjects died.
When the study was launched, none of the adults were weak. They could walk a little under half a kilometer, climb 10 steps and independently complete daily activities.
In the latest findings, the researchers noted that those with a weak nose were 30 percent more likely to die by year 13 than people with a good sense of smell. The findings were reported last month in the scientific publication Annals of Internal Medicine.
Honglei Chen was the lead writer of a report on the study. He is a doctor with Michigan State University in East Lansing, Michigan.
Chen said the connection between a poor sense of smell and an increased risk of dying was limited to adults who first reported good-to-excellent health. This suggests that a poor sense of smell is an early and sensitive sign for worsening health before it is recognizable in medical tests.
"Poor sense of smell is likely an important health marker in older adults beyond what we have already known about," noted Chen. He was talking about links to memory loss through dementia, Parkinson's disease, a poor diet and safety risks.
People who started out the study in excellent or good health were 62 percent more likely to die by year 10 if they had a poor sense of smell, his team reported. But smell did not appear to make a meaningful difference in death rates for people who were in fair to poor health at the start of the study.
With a poor sense of smell, people were more likely to die of brain and heart diseases, but not of cancer or breathing disorders.
The results also suggest that a poor sense of smell may be an early warning for poor health in older age that goes beyond dementia or other neurodegenerative diseases. These often signal the beginning of a weakening of the mind or body.
Dementia and Parkinson's disease explained only 22 percent of the higher death risk tied to a poor sense of smell. Weight loss explained just six percent of this connection, researchers estimated. That leaves more than 70 percent of the higher mortality rates tied to a weak nose unexplained.
The connection between a poor sense of smell and mortality risk did not appear to change based on sex or race. It also did not change based on individuals' other qualities, such as the way they live or ongoing health conditions.
One limitation of the study is that the older adults were relatively active. This makes it possible that results might be different for younger people or for individuals who are weak, the study noted.
Researchers also only tested smell at one point in time. They did not look at whether changes in subjects' ability to smell over time might influence mortality. Researchers also lacked information about medical causes of a weak sense of smell.
Annals of Internal Medicine published an editorial with the report.
In it, Vidyulata Kamath noted that as people age, they may not know their sense of smell is worsening. For that reason, doctors may want to test the sense of smell in older patients who are at risk of disease or injury.
Kamath is with the Johns Hopkins University School of Medicine in Baltimore.
"The take-home message is that a loss in the sense of smell may serve as a bellwether for declining health," Kamath wrote.
I'm Pete Musto.
1.sense of smell 嗅觉
With their excellent sense of smell, dogs can help do police work.
2.poor diet 不良饮食习惯
A poor diet lowers your resistance to illness.
3.over time 随着时间流逝
Over time you can figure out a new routine that works for all of you.
4.die of 死于
Every year, 3000 people in our community die of cancer.
5.For that reason, doctors may want to test the sense of smell in older patients who are at risk of disease or injury.
at risk of 有...的风险
He saved three children alive at risk of his life.
An estimated seven million people are at risk of starvation.
6.For that reason, doctors may want to test the sense of smell in older patients who are at risk of disease or injury.
For that reason 因此
For that reason the engineers did not adopt the plan.
For that reason, I consider it something we must never do.
这项研究是美国研究人员进行的一个项目，历时超过13年 。他们让约2300名男性和女性辨别12种常见气味 。研究对象的年龄为71 到 82岁 。
这项研究发起之时，所有成年人的身体都很健康 。他们可以徒步不到半公里，爬10级台阶，独立完成日常活动 。
在最新的研究结果中，研究人员指出，嗅觉较差的人在13年后死亡的概率比嗅觉灵敏的人高30% 。这些发现发表在上个月的科学出版物《内科医学年鉴》上 。
陈洪磊（音译）是这项研究报告的主要作者 。他是密歇根州东兰辛市密歇根州立大学的医生 。
陈洪磊表示，嗅觉差和死亡风险增加之间的联系仅限于首次报告身体状况从良好到极好的成年人 。这表明，嗅觉差是健康状况恶化的早期敏感信号，而医学测试无法检测出来 。
陈洪磊说：“嗅觉差可能是老年人健康的一个重要标志，这一点超出了我们已知的范围 。”他谈到了痴呆症、帕金森氏综合症、不良饮食和安全风险与记忆力丧失的关系 。
他的研究小组报称，如果嗅觉差，那些一开始身体状况良好或极好的成年人10年后死亡的概率会增加62% 。而对于那些最初健康状况相对较差的人来说，嗅觉似乎并没有对死亡率产生明显影响 。
研究结果还表明，嗅觉差可能是老年时期健康状况不佳的早期预警，而这不属于痴呆症或其他神经退行性疾病 。这些疾病通常是精神或身体开始衰弱的信号 。
研究人员估计，嗅觉较差老年人死亡率增高的因素22%可归咎于痴呆症、帕金森氏综合症 。而体重下降只占比6% 。这导致70%以上的高死亡率与难以解释的嗅觉差因素有关 。
嗅觉差和死亡风险之间的联系似乎不会因为性别或种族而改变 。它也不会因为个人的其他因素而改变，比如生活方式或持续的健康状况 。
该研究的局限性之一是，这些老年人相对来说比较活跃 。研究指出，因此年轻人或身体虚弱的人可能需要因人而异 。
研究人员也只是测试了某一时间点的嗅觉状况 。他们没有根据时间的推移，继续研究受试者嗅觉能力的变化是否会影响死亡率 。研究人员也缺乏关于嗅觉差的医学原因的信息 。
卡马斯（Vidyulata Kamath）在社论中指出，随着人们年龄的增长，他们可能不知道自己的嗅觉正在恶化 。鉴于此，医生可能需要测试有患病或受伤风险的老年人的嗅觉 。