·健康·
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The Hidden Health Risks of Working the Night Shift

夜勤がもたらす見えない健康リスク

#sleep#health#night shift#dementia#brain
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Working the night shift might do more than just make you feel tired. It could also hurt your brain and body in ways you cannot see.

Sleep is not just for resting. While we are asleep, our brains do important work. They organize our memories, process our emotions, and help our immune systems. Our bodies also repair muscle tissue while we sleep.

How the Brain Cleans Itself

One of the most exciting new discoveries is that the brain cleans itself during sleep. The brain has a tiny drainage system. Fluid flows through this system to wash away waste products that build up during the day.

If you do not sleep, these waste products stay in the brain. Researchers from the University of Cambridge studied the brain scans of more than 40,000 healthy people. They found that people with weak brain drainage systems were much more likely to get dementia years later.

When you do not sleep for even one night, the levels of harmful proteins like amyloid increase in your brain. These are the same proteins found in the brains of people with Alzheimer's disease. If you work the night shift for many years, this waste can build up and cause serious damage.

The Long-Term Danger

A Swedish study tracked more than 13,000 shift workers for up to 41 years. The study showed that working shifts in middle age raised the risk of dementia by 36%. The risk was higher for people who worked night shifts for a longer time.

Poor sleep is also bad for your heart. When you sleep only 4.5 hours for a few nights, your body's immune system becomes too active. This causes inflammation, which is linked to heart disease.

Additionally, broken sleep increases a stress hormone called cortisol. High cortisol levels make it harder for the body to use insulin. This can lead to diabetes. High cortisol also makes sleep even worse, creating a dangerous cycle.

Furthermore, the World Health Organization says that night shift work is "probably carcinogenic to humans." This means it might cause cancer. Night shifts disrupt the body's natural clock. This changes how the body makes melatonin, a hormone that helps stop tumors from growing.

Taking Control of Your Sleep

Sleep is a main pillar of health, just like food and exercise. We need to take control of it.

Some researchers believe that humans are not naturally meant to sleep in one long block. In the past, people often slept in two halves with a period of wakefulness in the middle. Some shift workers are now trying this two-part sleep pattern. However, scientists are still studying whether this type of sleep is healthy.

No matter how you sleep, protecting your sleep schedule is one of the most important things you can do for your long-term health.

学習ノート

語彙

レベル意味
dementiaB2認知症
inflammationB2炎症
disruptB2〜を乱す、中断させる
pillarB2柱、支柱

言語メモ

  • 「サーカディアンリズム(体内時計)」や「メラトニン」の分泌といった科学的知見をもとに、夜勤が健康に及ぼす影響について説明されています。特に、近年発見された脳の老廃物排出システム(グリンパティック系)と認知症の関連性は、睡眠の重要性を再認識させる最新の研究結果として注目されています。

練習

読んだ内容を確認しましょう。

  1. Night shifts   the body's natural clock.

  2. According to the article, why is working the night shift linked to dementia?

Source: BBC News