A study by public health scientists has revealed that getting too much or too little sleep can prematurely age your brain by up to seven years.
公眾健康專家發布的報告稱，過多或過少的睡眠都會使大腦早衰，最多可早衰7年。

They found that middle-aged adults whose sleep decreased to less than six hours a night over a five-year period suffered lower scores in reasoning and vocabulary tests.
科學家發現連續5年每晚睡眠少于6小時的中年人在關于推理和詞匯的測試中得分較低。

Those whose nightly sleep increased to more than eight hours also showed signs of accelerated cognitive decline.
那些每晚睡眠超過8個小時的人也表現出感知能力衰退的跡象。

But they found that women who had maintained seven hours of sleep per night performed best in cognitive tests as did men who slept between six and eight hours.
科學家發現每晚睡7小時的女人和每晚睡6-8小時的男人在感知能力測試中表現最好。

The findings suggest that regularly sleeping for seven hours during the night can help to reduce the cognitive decline that occurs as we grow older.
這項發現表明每晚睡7小時，能減少大腦早衰。