2020年5月1日。锻炼的效果相当于减少了四年的大脑衰老。该研究使用磁共振成像(MRI)扫描来测量不同活动水平的人的大脑，包括那些不太活跃的人和非常活跃的人。扫描结果显示，不太活跃的人大脑体积更小。“这些结果令人兴奋，因为它们表明，人们只要变得更加活跃，就可能潜在地防止大脑萎缩和大脑老化的影响，”该研究的作者、纽约哥伦比亚大学的顾一安博士说，他是美国神经病学学会的成员。“最近的研究表明，随着人们年龄的增长，体育活动可能会降低认知能力下降和痴呆症的风险。我们的研究使用脑部扫描来测量大脑的各种各样的人群,发现那些从事前三名最高水平的身体活动的大脑体积相当于四岁大脑衰老的人比底部第三活动水平。这项研究涉及1557人，平均年龄75岁。没有人患痴呆症，但296人有轻度认知障碍，28%的人有APOE基因，而APOE基因与患阿尔茨海默病的风险更高有关。研究人员对参与者进行了身体检查、思维和记忆测试，并询问了他们的日常任务和其他体育活动。研究人员随后计算出每个人在这些任务和活动上花费的时间和精力。 Researchers divided people into three groups: those who were inactive; those who were somewhat active meaning each week they either had roughly two-and-a-half hours of low-intensity physical activity, one-and-a-half hours of moderate physical activity or one hour of high-intensity physical activity; and those who were most active meaning each week they either had seven hours of low-intensity physical activity, four hours of moderate physical activity or two hours of high-intensity physical activity. Researchers then reviewed MRI brain scans of all participants and found that when compared to the people in the inactive group, those who were most active had larger total brain volume. After adjusting for age, sex, education, race/ethnicity and APOE gene status, the average brain size for those who were inactive was 871 cubic centimeters compared to 883 cubic centimeters for those who were most active, a difference of 12 cubic centimeters, or 1.4%, or the equivalent of nearly four years of brain aging. The results remained similar even after excluding people who had mild cognitive impairment. “Our results add to the evidence that more physical activity is linked to larger brain volume in older people,” said Gu. “It also builds on evidence that moving your body more often throughout one’s life may protect against loss of brain volume.” A limitation of the study was that information on physical activity relied on a person’s ability to remember how often and for how much time they were active. Additionally, Gu noted that due to the particular study design, this study does not prove that exercise prevents brain shrinkage; it shows an association. The study was supported by the National Institute on Aging and the National Institutes of Health.