Are You Getting Enough Sleep?
From VOA Learning English, this is the Health & Lifestyle report.
We spend about one-third of our lives asleep. This may sound like a lot of time, but it is not wasted.
Our bodies need sleep to stay healthy. Not getting enough sleep, or as we sometimes say shut-eye, can make us sick.
Sleep and our immune system
The immune system protects the body from diseases and infections. Not getting enough sleep hurts this protective system.
The Mayo Clinic is a nonprofit research hospital in the United States. Its website explains that when we sleep our bodies release proteins that support sleep and help us fight infections. They add that infection-fighting antibodies and cells are reduced during periods when you don't get enough sleep.
A new study from the University of Washington in the U.S. seems to confirm this. Dr. Nathaniel Watson was the lead writer of the study. He is also co-director of the university's Medicine Sleep Center at Harborview Medical Center.
Watson says his study shows that the immune system works best when the body gets enough sleep.
For the study, Watson and his team studied 11 pairs of identical twins. This is an important difference from other sleep studies. Other research did not study identical twins.
The identical twins, however, had different sleep patterns. Researchers found that the twin who slept less had a weaker immune system.
Watson says his study showed for the first time that a long-term lack of sleep shuts down parts of the immune system. He says parts that move white blood cells around the body are affected. White blood cells fight infection in the body.
Watson adds that the results confirm a finding of other sleep studies. They found that when sleep-deprived people are given a vaccine, fewer antibodies are produced. If sleep-deprived people are then exposed to a virus, he says, "they are more likely to get the virus."
Watson's study provides more evidence that sleep is important to "overall health and well-being." And sleep is especially important to immune health.
The researchers published their findings in the journal Sleep.
How much sleep is enough?
To stay in good health, experts at the Mayo Clinic say that adults should get seven to eight hours of sleep. Teenagers need nine to 10 hours. And school-aged children may need more than 10 hours of sleep a night.
Experts say the quality and quantity of our sleep becomes poor as we age. This happens because brain circuits that control sleep slowly begin to weaken.
Experts say the process begins in our 30s. By the time we reach our 50s, the average person has lost 50 percent of their ability to have a restful sleep.
These people also have trouble falling asleep and staying asleep through the night. From middle age on, they say these problems only get worse, and they can affect our health.
Signs you may not be getting enough sleep
The website Health.com lists several signs that may mean you are not getting enough sleep.
You're always hungry or you've gained weight. A lack of sleep can affect the hormones that tell your brain you have eaten enough.
You have trouble making decisions. A lack of sleep may affect your higher level brain functions, such as problem solving.
You have trouble remembering things. Sleep helps prepare the brain for new memories.
You feel very emotional. People who are sleep deprived may feel unable to control their emotions, whether they be angry, sad or happy.
Your skin doesn't look good. When we sleep, the body repairs damaged cells, like skin cells. (We don't call it beauty sleep for nothing!)
You are having trouble seeing. When you're tired you may not be able to control your eye muscles.
How to improve your sleep
There are things people can do get better sleep.
Health experts recommend exercise and avoiding work on computers and electronic devices before bed. A cool room is also a better environment for sleeping.
And that's the Health & Lifestyle report.
I'm Anna Matteo.
1.work on 影响；从事于
To work on this show you've got to have balls.
2.electronic devices 电子设备
Many of the radio and electronic devices used are similar to those of artificial satellites.
3.middle age 中年；中世纪
Some of the diseases of middle age may be prevented by improving nutrition.
4.immune system 免疫系统
The patient's immune system would reject the transplanted organ as a foreign object.
1.You are having trouble seeing.
have trouble(in) doing 做某事有困难
I never have trouble sleeping in a strange place.
Left-handers have trouble using can-openers, scissors, and potato peelers.
2.A lack of sleep can affect the hormones that tell your brain you have eaten enough.
A lack of 缺乏
I was hampered by a lack of information.
There is a lack of confidence in the government's ability to manage the economy
一生之中，我们用三分之一的时间来睡觉 。虽然听起来时间很长，但这些时间绝对没有浪费 。
人体需要睡眠来保持健康 。睡眠不足容易生病 。
免疫系统可以帮助人体抵御疾病和感染 。而缺乏充足的睡眠会伤害免疫系统 。
梅奥诊所是美国一家非盈利性研究医院 。其官网上指出，入睡后人体会释放出蛋白质从而保证睡眠并对抗感染 。
美国华盛顿大学一项新研究似乎证实了这一观点 。纳撒尼尔·沃森（Nathaniel Watson）博士是该研究的首席作者 。他还是华盛顿大学港景医学中心睡眠医学中心的联席主任 。
为了进行研究，沃森和团队分析了11对同卵双胞胎，这与其它的睡眠研究之间有重大区别 。其它研究未曾分析过同卵双胞胎 。
双胞胎的睡眠模式并不相同 。研究人员发现，双胞胎中睡眠较少的人免疫力更脆弱 。
沃森表示，其研究首次证明，长期缺乏睡眠会导致免疫系统的部分功能停止运作 。负责输送白细胞的功能会受到影响 。
沃森还表示，该研究还证实了其它睡眠研究的结果 。他们发现，睡眠不足者接种疫苗时会产生较少的抗体 。如果睡眠不足者再接触病毒，“他们仍然可能会感染 。”
该研究为证实睡眠对人体健康和福祉的重要性提供了更多佐证 。睡眠对免疫系统也至关重要 。
专家表示，30多岁后睡眠出现减弱 。等到了50多岁，普通人几乎失去了近一半的安眠能力 。
这部分人还伴有难以入睡或者易醒的问题 。人过中年，这些问题会慢慢加重，影响到我们的健康 。
经常觉得饥饿或体重增加 。睡眠不足会导致激素无法将饱腹的信号传递给大脑 。
迟疑不决 。缺乏睡眠会影响大脑高级功能，如解决问题等 。
记忆力衰退 。充足睡眠可帮助大脑接收新记忆 。
变得情绪化 。睡眠不足者可能难以控制自己的喜怒哀乐 。
皮肤暗淡无光 。人体会在入睡后修复受损细胞，如皮肤细胞 。（美容觉一词并非空穴来风 。）
视力下降 。在疲劳状态下，你可能无法控制眼部肌肉 。
健康专家建议睡前进行锻炼，还要远离电脑和电子设备 。凉爽的房间也有助于安眠 。