Seniors who can identify smells like roses, turpentine, paint-thinner and lemons, and have retained their senses of hearing, vision and touch, may have half the risk of developing dementia as their peers with marked sensory decline.

那些能辨别出玫瑰、松节油、颜料稀释剂和柠檬等气味，并保持听觉、视觉和触觉正常的老年人，与那些感觉明显衰退的同龄人相比，患痴呆症的风险可能要低一半。

In a study by UC San Francisco, researchers tracked close to 1,800 participants in their 70s for a period of up to 10 years to see if their sensory functioning correlated with the development of dementia. At the time of enrollment, all participants were dementia-free, but 328 participants (18 percent) developed the condition over the course of the study.

加州大学旧金山分校（UC San Francisco）的一项研究中，研究人员在长达10年的时间里追踪了近1800名70多岁的参与者，想知道他们的感觉功能是否与痴呆症的发展有关。在进行初步登记时，所有的参与者都没有痴呆症状，但是在整个研究过程中有328名参与者(18%)逐渐出现了痴呆症。   

Among those whose sensory levels ranked in the middle range, 141 of the 328 (19 percent) developed dementia. This compares with 83 in the good range (12 percent) and 104 (27 percent) in the poor range, according to the study, which published in Alzheimer’s and Dementia: The Journal of the Alzheimer’s Association on July 20, 2020.

在328名感觉水平处于中等范围的人中，有141人(19%)患上了痴呆症。这项研究发表在2020年7月20日的《阿尔茨海默病与痴呆》（ Alzheimer’s and Dementia）杂志上。研究结果显示，比较得出，健康范围内的参与者共83名患病(占12%)和较差范围内的参与者共104名患病(占27%)。

Previous research has centered on the link between dementia and individual senses, but the UCSF researchers’ focus was on the additive effects of multiple impairments in sensory function, which emerging evidence shows are a stronger indicator of declining cognition.

之前的研究集中在痴呆和个体感觉之间的联系上，但是加州大学旧金山分校的研究人员关注的是感觉功能多重损伤的叠加效应，新出现的证据表明，这是认知能力下降的一个更强的指标。

“Sensory impairments could be due to underlying neurodegeneration or the same disease processes as those affecting cognition, such as stroke,” said first author Willa Brenowitz, Ph.D., of the UCSF Department of Psychiatry and Behavioral Sciences, and the Weill Institute for Neurosciences. “Alternatively, sensory impairments, particularly hearing and vision, may accelerate cognitive decline, either directly impacting cognition or indirectly by increasing social isolation, poor mobility and adverse mental health.”

“感觉障碍可能是由于潜在的神经退行性变或与影响认知的疾病过程相同的疾病，如中风，”第一作者Willa Brenowitz博士说，他来自加州大学旧金山分校精神和行为科学系，以及韦尔神经科学研究所（Weill Institute for Neurosciences）。“或者，感官障碍，特别是听力和视力，可能加速认知衰退，直接影响认知能力，或通过增加社会孤立、行动不便和不良心理健康问题间接影响认知能力。”

While multiple impairments were key to the researchers work, the authors acknowledged that a keen sense of smell, or olfaction, has a stronger association against dementia than touch, hearing or vision. Participants whose smell declined by 10 percent had a 19 percent higher chance of dementia, versus a 1-to-3-percent increased risk for corresponding declines in vision, hearing and touch.

尽管多种障碍是研究人员工作的关键，但作者承认，与触觉、听觉或视觉相比，嗅觉对预防痴呆的作用更大。嗅觉下降10%的参与者患痴呆症的几率要高出19%，而视力、听力和触觉相应下降的几率要高出1%到3%。

“The olfactory bulb, which is critical for smell, is affected fairly early on in the course of the disease,” said Brenowitz. “It’s thought that smell may be a preclinical indicator of dementia, while hearing and vision may have more of a role in promoting dementia.”

“对嗅觉至关重要的嗅球在疾病的早期就受到了影响，”Brenowitz说。“人们认为，气味可能是痴呆的临床前指标，而听觉和视觉可能在促进痴呆方面发挥更大的作用。”

The 1,794 participants were recruited from a random sample of Medicare-eligible adults in the Health, Aging and Body Composition study. Cognitive testing was done at the beginning of the study and repeated every other year. Dementia was defined by testing that showed a significant drop from baseline scores, documented use of a dementia medication or hospitalization for dementia as a primary or secondary diagnosis.

1794名参与者是从健康、衰老和身体组成（Health, Aging and Body Composition）研究里享受医保的成年人中随机抽取的。认知测试是在研究开始时进行的，每隔一年重复一次。痴呆的定义是通过测试显示从基线得分显著下降，记录使用痴呆药物或为痴呆住院作为主要或次要诊断。

Multisensory testing was done in the third-to-fifth year and included hearing (hearing aids were not allowed), contrast-sensitivity tests for vision (glasses were permitted), touch testing in which vibrations were measured in the big toe, and smell, involving identifying distinctive odors like paint-thinner, roses, lemons, onions and turpentine.

当多种感觉研究进行到第3 ~ 5年，包括听力测试(助听器不允许)，为视觉对比敏感度测试(眼镜被允许)，测量震动大脚趾的触觉测试，和气味，包括识别独特的气味像涂料稀释剂，玫瑰，柠檬，洋葱和松节油。

The researchers found that participants who remained dementia-free generally had higher cognition at enrollment and tended to have no sensory impairments. Those in the middle range tended to have multiple mild impairments or a single moderate-to-severe impairment. Participants at higher risk had multiple moderate-to-severe impairments.

研究人员发现，无痴呆症的参与者在登记时通常有较高的认知能力，而且几乎没有感觉障碍。感觉水平处于中等范围的参与者或多或少有多重轻度损伤或单一中度到重度损伤。感觉水平处于高风险的参与者有多种中度至重度损伤。

“We found that with deteriorating multisensory functioning, the risk of cognitive decline increased in a dose-response manner,” said senior author Kristine Yaffe, M.D., of the UCSF departments of Psychiatry and Behavioral Sciences, Epidemiology and Biostatistics, and Neurology, as well as the San Francisco VA Health Care System. “Even mild or moderate sensory impairments across multiple domains were associated with an increased risk of dementia, indicating that people with poor multisensory function are a high-risk population that could be targeted prior to dementia onset for intervention.”

“我们发现，随着多种感觉功能的恶化，认知能力下降的风险以剂量反应的方式增加，”加州大学旧金山分校精神病学和行为科学、流行病学和生物统计学、神经学以及旧金山VA卫生保健系统（San Francisco VA Health Care System）的资深作者Kristine Yaffe医学博士说。“即使是跨多个领域的轻度或中度感官损伤也与痴呆风险增加有关，这表明多种感官功能不佳的人是高风险人群，可以在痴呆发病前进行干预。”

The 780 participants with good multisensory function were more likely to be healthier than the 499 participants with poor multisensory function, suggesting that some lifestyle habits may play a role in reducing risks for dementia. The former group was more likely to have completed high school (85 percent versus 72.1 percent), had less diabetes (16.9 percent versus 27.9 percent) and were marginally less likely to have cardiovascular disease, high-blood pressure and stroke.

780名多种感觉功能良好的参与者比499名多种感觉功能差的参与者更健康，这表明某些生活习惯可能在降低痴呆症风险方面发挥了作用。前者更有可能完成高中学业(85%对72.1%)，患糖尿病的几率更低(16.9%对27.9%)，患心血管疾病、高血压和中风的几率也稍低。