健康生活:改變生活方式可預防老年癡呆

Lifestyle Changes Can Reduce Risk Of Alzheimer's A new, theoretical analysis finds that about half of the risk factors for Alzheimer's disease are potentially changeable, and that reducing them could substantially decrease the number of new cases of disease worldwide, according to a study to be presented Tuesday at the Alzheimer's Association International Conference.

據老年癡呆症協會國際會議（Alzheimer's Association International Conference）發表的一項研究，一項新的理論分析發現，老年癡呆症(Alzheimer’s disease，又稱阿茲海默症)的風險因素大約有一半可能是可變的，降低這些風險因素可能大大降低全世界範圍內的新發病數量。

The study is the first known analysis that tries to quantify and compare how risk factors are associated with Alzheimer's. It will be published Tuesday on the journal Lancet Neurology's website after the conference presentation.

這項研究是已知的首個試圖將風險因素與老年癡呆症的關聯加以量化並進行比較的分析。在上述國際會議上演示後，這項研究將在醫學雜誌《柳葉刀•神經病學》(Lancet Neurology)的網站上發表。

Factors that increase one's risk for Alzheimer's that are considered modifiable include diabetes, high blood pressure, obesity, smoking, sedentary behavior, depression and low educational level, say the authors from the University of California, San Francisco.

來自加州大學舊金山分校(University of California, San Francisco)的研究作者們說，在可增加個體患老年癡呆症風險的因素中，被認爲可變的因素包括糖尿病、高血壓、肥胖、抽菸、久坐、情緒低落以及受教育水平低。

In the U.S., physical inactivity is the biggest changeable factor, accounting for 21% of the risk for Alzheimer's, followed by depression and smoking. Added together, the factors account for about 50% of the risk.

在美國，缺乏鍛鍊是最大的可變因素，佔老年癡呆症風險的21%，排在其後的是情緒低落和抽菸。這三大因素加在一起佔了50%左右的風險。

If these risk factors were decreased by just 10%, about 184,000 Alzheimer's cases in the U.S. and 1.1 million cases world-wide could be prevented, according to the research. A reduction of 25% on all seven risk factors could prevent nearly half a million cases in the U.S. and more than three million world-wide, the analyses showed.

根據這項研究，如果這些風險因素下降區區10%，在美國就會有大約18.4萬老年癡呆症患者可以得到預防，全球預防人數爲110萬。分析顯示，如果所有七項風險可下降25%，美國的預防人數就會接近50萬，全球範圍內超過300萬。

There are some five million people in the U.S. thought to have Alzheimer's, according to the Alzheimer's Association, and about 36 million cases globally, according to Alzheimer's Disease International.

據老年癡呆症協會的數據，美國有大約500萬人被認爲患有老年癡呆症，而國際老年癡呆症協會（Alzheimer's Disease International）數據顯示，全球患者約3,600萬。

"The estimates suggest that in the population, up to half of Alzheimer's cases could be modifiable,' said Deborah Barnes, a psychiatry professor at UCSF who will present the results. "If we changed those risk factors…it could have this huge impact' at the population level, she said in an interview.

加州大學舊金山分校的精神病學教授黛博拉•巴尼斯(Deborah Barnes)負責演示研究結果。她接受採訪時說，上述預計表明，所有人口中最多一半的老年癡呆症病患的病情可以減輕。如果我們改變這些風險因素……就有可能在羣體水平上產生這種巨大的效應。

One caveat to these findings: They are based on mathematical models that predict what might happen if the assumptions on which the model was based are real. In this case, the researchers assumed that the risk factors caused Alzheimer's disease, which means that if they were modified, the rates of Alzheimer's would change as well.

關於上述結果需要提醒的一點是：它們是基於數學模型，如果這些模型所依據的前提是正確的，它們就可以預測可能發生的情況。在這項研究中，研究人員假定是這些風險因素導致了老年癡呆症，這就意味着如果這些風險因素得到修正，老年癡呆症的比例也會隨之變化。

In reality, the causes of Alzheimer's are still unclear, and it hasn't been proven that stopping smoking, for example, actually lowers one's risk of getting dementia.

事實上，老年癡呆症的起因仍然不明，而諸如戒菸等行爲事實上是否能降低癡呆風險也未經驗證。

These estimates were calculated based on published data about how frequently the risk factors occur in the population as well as the extent to which each factor increases one's risk of Alzheimer's, known as relative risk.

這些估計是根據已發佈的相關數據計算出來的，包括風險因素在人羣中發生的頻率，以及每種因素會在多大程度上加劇老年癡呆症風險，也就是相對風險。

For instance, depression nearly doubles one's risk of developing Alzheimer's. Each factor alone increases one's risk of Alzheimer's anywhere from about 50% to 100%, according to Dr. Barnes.

比如說，抑鬱幾乎會導致罹患老年癡呆症的風險增加一倍。據巴尼斯說，每種因素各自都會導致患老年癡呆症的風險增加約50%至100%。

The next step in this work is to do prevention trials to try to modify these risks to see if they can actually stave off Alzheimer's, Dr. Barnes says. She hopes to conduct a trial on physical activity, because it 'seems like the biggest bang for your buck,' because it is known to help the brain, the heart and mood, she says.

巴尼斯說，這項研究的下一步工作是展開預防試驗，試圖修正這些風險，看看能否真的防止老年癡呆症。她說希望負責一項針對體育鍛煉情況的試驗，因爲這似乎是最重要的一項，衆所周知，體育鍛煉對大腦、心臟和情緒都有益。