运动如何预防阿尔茨海默氏症

运动员知道剧烈运动可以释放大量的内啡肽：它是一种“感觉良好”的激素，可以促进情绪。根据由哥伦比亚大学Vagelos医学院外科医学院和Taub阿尔茨海默病和衰老大脑研究所研究员Ottavio Arancio博士共同领导的一项研究，现在有证据表明运动会产生另一种激素，它可以改善记忆并预防阿尔茨海默病。

Athletes know a vigorous workout can release a flood of endorphins: “feel-good” hormones that boost mood. Now there’s evidence that exercise produces another hormone that may improve memory and protect against Alzheimer’s disease, according to a study co-led by Ottavio Arancio, MD, PhD, a researcher at Columbia University’s Vagelos College of Physicians and Surgeons and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain.

该研究发表在Nature Medicine上。

The study was published in Nature Medicine.

众所周知，身体活动可以改善记忆力，研究表明它也可以降低阿尔茨海默病的风险。但是研究人员不明白为什么。

Physical activity is known to improve memory, and studies suggest it may also reduce the risk of Alzheimer’s disease. But researchers don’t understand why.

几年前，运动研究人员发现了一种叫做鸢尾红素的激素，它在体力活动中被释放到血液循环中。初步研究表明，鸢尾素主要在能量代谢中发挥作用。但是最新的研究发现，这种激素还可以促进大脑海马的神经元生长，这是一个对学习和记忆至关重要的区域。

A few years ago, exercise researchers discovered a hormone called irisin that is released into the circulation during physical activity. Initial studies suggested that irisin mainly played a role in energy metabolism. But newer research found that the hormone may also promote neuronal growth in the brain’s hippocampus, a region critical for learning and memory.

哥伦比亚大学Vagelos医生和外科医生学院的病理学和细胞生物学和医学教授Arancio说：“这增加了鸢尾素可能有助于解释为什么身体活动可以改善记忆并且似乎在阿尔茨海默病等脑部疾病中发挥保护作用的可能性”。

“This raised the possibility that irisin may help explain why physical activity improves memory and seems to play a protective role in brain disorders such as Alzheimer’s disease” says Arancio, who is a professor of pathology and cell biology and of medicine at Columbia University Vagelos College of Physicians and Surgeons.

Irisin在阿尔茨海默氏症患者的大脑中减少了

Irisin is reduced in brains of people with Alzheimer’s

在这项新研究中，Arancio和他在巴西里约热内卢联邦大学和加拿大皇后大学的同事们首先在人们中寻找鸢尾素和阿尔茨海默氏症之间的联系。使用来自脑库的组织样本，他们在人类海马区发现了鸢尾素，并且阿尔茨海默氏症患者的海马区鸢尾素激素水平较低。

In the new study, Arancio and his colleagues at the Federal University of Rio de Janeiro in Brazil and Queens University in Canada first looked for a link between irisin and Alzheimer’s in people. Using tissue samples from brain banks, they found that irisin is present in the human hippocampus and that hippocampal levels of the hormone are reduced in individuals with Alzheimer’s.

为了探索鸢尾素在大脑中的作用，该团队转向了老鼠。这些实验表明，小鼠中的鸢尾素可以保护大脑的突触和动物的记忆：当健康小鼠海马区的鸢尾素被破坏时，突触和记忆力减弱。同样，提高大脑中的鸢尾素水平也可以改善大脑健康两个标志-突触和记忆力大脑。

To explore what irisin does in the brain, the team turned to mice. These experiments show that irisin, in mice, protects the brain’s synapses and the animals’ memory: When irisin was disabled in the hippocampus of healthy mice, synapses and memory weakened. Similarly, boosting brain levels of irisin improved both measures of brain health.

游泳可增强鸢尾素，保护小鼠的记忆力

Swimming boosts irisin, protects memory in mice

然后研究人员研究了运动对鸢尾素和大脑的影响。在这项研究最引人注目的实验中，研究人员发现，几乎每天游泳五周的小鼠尽管注射了β淀粉样蛋白 – 这是一种与阿尔茨海默病有关的神经元堵塞，记忆抢劫蛋白，但并未发生记忆障碍。

The researchers then looked at the effect of exercise on irisin and the brain. In the study’s most compelling experiments, the researchers found that mice who swam nearly every day for five weeks did not develop memory impairment despite getting infusions of beta amyloid — the neuron-clogging, memory-robbing protein implicated in Alzheimer’s.

研究人员还发现，用药物阻断鸢尾素完全消除了游泳的好处。在用β淀粉样蛋白输注后，游泳并用鸢尾素阻断物质治疗的小鼠在记忆测试中表现不比久坐不动的动物强。

Blocking irisin with a drug completely eliminated the benefits of swimming, the researchers also found. Mice who swam and were treated with irisin-blocking substances performed no better on memory tests than sedentary animals after infusions with beta amyloid.

Arancio说，这些研究结果表明，可以利用鸢尾素来寻找预防或治疗人类痴呆的新疗法。他的团队现在正在寻找可以增加激素大脑水平或可以模仿其作用的药物化合物。

Together the findings suggest that irisin could be exploited to find a novel therapy for preventing or treating dementia in humans, Arancio says. His team is now searching for pharmaceutical compounds that can increase brain levels of the hormone or can mimic its action.

“与此同时，我当然会鼓励每个人锻炼身体，促进大脑功能和整体健康，”他说。 “但对于许多人来说，这是不可能的，特别是那些与年龄相关的疾病，如心脏病，关节炎或痴呆症。对于那些个体，特别需要能够模仿鸢尾素的作用并保护突触并防止认知能力下降的药物。 “

“In the meantime, I would certainly encourage everyone to exercise, to promote brain function and overall health,” he said. “But that’s not possible for many people, especially those with age-related conditions like heart disease, arthritis, or dementia. For those individuals, there’s a particular need for drugs that can mimic the effects of irisin and protect synapses and prevent cognitive decline.”

How exercise may protect against Alzheimer’s

Columbia University Irving Medical Center