【English】

Scientists at the University of California, Berkeley have discovered a compelling link between deep sleep and the brain's ability to clear toxic proteins associated with Alzheimer's disease. The study, published in the journal Science, suggests that quality deep sleep may serve as a natural defense mechanism against cognitive decline.

The research team monitored the brain activity of 32 healthy adults aged 60 to 80 using advanced EEG technology. They found that participants who experienced more slow-wave sleep — the deepest stage of non-REM sleep — had significantly lower levels of tau and beta-amyloid proteins in their brains. These proteins are hallmarks of Alzheimer's disease.

During deep sleep, the brain activates a waste-clearance system called the glymphatic system. This system flushes out toxic metabolic byproducts, including the proteins that form the sticky plaques seen in Alzheimer's patients.

The findings are particularly significant because deep sleep quality naturally declines with age. By the time people reach their 60s, they typically lose 60 to 70 percent of the deep sleep they experienced in their 20s. This decline may create a vicious cycle: less deep sleep leads to more protein accumulation, which in turn further disrupts sleep quality.

The researchers suggest several evidence-based strategies for improving deep sleep, including maintaining a consistent sleep schedule, keeping the bedroom temperature between 18-19°C, avoiding caffeine after 2 PM, and engaging in regular aerobic exercise.

【中文翻译】

加州大学伯克利分校的科学家发现，深度睡眠与大脑清除阿尔茨海默症相关有毒蛋白质的能力之间存在令人信服的联系。这项发表在《科学》杂志上的研究表明，高质量的深度睡眠可能是预防认知能力下降的天然防御机制。

研究团队使用先进的脑电图技术监测了32名年龄在60至80岁之间的健康成年人的大脑活动。他们发现，经历更多慢波睡眠（非快速眼动睡眠的最深阶段）的参与者，其大脑中的tau蛋白和β-淀粉样蛋白水平显著降低。这些蛋白质是阿尔茨海默症的标志性特征。

在深度睡眠期间，大脑会激活一个叫做胶质淋巴系统的废物清除系统。这个系统会冲刷掉有毒的代谢副产物，包括在阿尔茨海默症患者大脑中形成粘性斑块的蛋白质。

这些发现尤为重要，因为深度睡眠的质量会随着年龄增长自然下降。到60多岁时，人们通常会丧失20多岁时所经历的60%至70%的深度睡眠。这种下降可能形成恶性循环：深度睡眠减少导致蛋白质积累增多，而蛋白质积累又会进一步干扰睡眠质量。

研究人员提出了几种有科学依据的改善深度睡眠的策略，包括保持规律的作息时间、将卧室温度控制在18-19°C、下午2点后避免摄入咖啡因，以及定期进行有氧运动。

【重点词汇】

• compelling /kəmˈpelɪŋ/ — 令人信服的，引人注目的
• toxic /ˈtɒksɪk/ — 有毒的
• cognitive decline /ˈkɒɡnɪtɪv dɪˈklaɪn/ — 认知能力下降
• slow-wave sleep /sləʊ weɪv sliːp/ — 慢波睡眠（深度睡眠阶段）
• hallmark /ˈhɔːlmɑːk/ — 标志，特征
• waste-clearance /weɪst ˈklɪərəns/ — 废物清除
• vicious cycle /ˈvɪʃəs ˈsaɪkl/ — 恶性循环
• aerobic exercise /eəˈrəʊbɪk ˈeksəsaɪz/ — 有氧运动