Getting a lot of exercise may help slow brain shrinkage in people with early Alzheimer's disease, a preliminary study suggests. Analysis found that participants who were more physically fit had less brain shrinkage than less-fit participants. However, they didn't do significantly better on tests for mental performance.

That was a surprise, but maybe the study had too few patients to make an effect show up in the statistical analysis, said Dr. Jeffrey Burns, one of the study's authors.

He also stressed that the work is only a starting point for exploring whether exercise and physical fitness can slow the progression of Alzheimer's. The study can't prove an effect because the participants were evaluated only once rather than repeatedly over time, he said.

While brains shrink with normal aging, the rate is doubled in people with Alzheimer's, he said.

Burns, who directs the Alzheimer and Memory Program at the University of Kansas School of Medicine in Kansas City, reports the work with colleagues in Tuesday's issue of the journal Neurology.

The study included 57 people with early Alzheimer's. Their physical fitness was assessed by measuring their peak oxygen demand while on a treadmill, and brain shrinkage was estimated by MRI scans.

Dr. Sam Gandy, who chairs the medical and scientific advisory council of the Alzheimer's Association, said the result fits in with previous indications that things people do to protect heart health can also pay off for the brain.

初步的研究建議，多鍛煉可以幫助早期阿爾茨海默氏癥的患者延緩腦萎縮。分析發現身體更健康的參與者的腦萎縮量比其他參與者的腦萎縮量要小。然而，他們在精神方面的測試上并不突出。

那令人驚奇，可也許這個研究的參與者太少以致不能在統計分析上顯出效果來，此次研究的發起人之一，杰弗瑞·伯恩斯博士說。

他還強調這只是探究鍛煉和健康的身體是否能延緩阿爾茨海默氏癥進程的起點。這次研究并不能證明什么療效，因為參與者們只被評估了一次而不是多次反復地被評估，他說到。

當大腦因為正常的老化而萎縮時，阿爾茨海默氏癥患者的幅度是正常人的兩倍，他接著說。

在堪薩斯市堪薩斯大學醫學院領導“阿爾茨海默氏癥與記憶”項目的伯恩斯在周二的神經病學期刊發布會上與同事一起報告了這項工作。

這項研究包括了57名早期阿爾茨海默氏癥患者。他們的身體健康程度通過對他們踏車訓練時需氧峰值的測量來評估，腦萎縮通過MRI掃描來評估。

阿爾茨海默氏癥協會咨詢委員會的醫學和科學方面的負責人薩姆·格蘭迪博士認為，結果表明之前人們保護心臟的措施也適用于大腦。