Level 3 Reading 6A

CH.11

第11章

Reading 6A THE WORLD'S FAVORITE DRUG It's 1:45 a.m., and 21-year-old Thomas Murphy is burning the midnight oil, studying for an important engineering exam he has at 2:00 in the afternoon later today. To stay awake and alert, he's had two cups of coffee in the last three hours and is now downing a popular energy drink— one that has two to three times the amount of caffeine as a similar sized can of soda. Many students like Murphy, as well as marathon runners, airline pilots, and long-distance travelers, owe their energy to one of humankind's oldest stimulants: caffeine. The power to counter physical fatigue and increase alertness is part of the reason caffeine ranks as the world's most popular mood-altering drug. It is found not only in sodas, energy drinks, coffee, and tea, but in diet pills, pain relievers (like aspirin), and chocolate bars. Many societies around the world have also created entire rituals around the use of caffeine. For example, there's the cafe culture of France, the tea ceremony in Japan, and the morning cup of coffee or tea that marks the start of the day in many cultures. Caffeine is present in many of the foods and drinks we consume, but is it good for us? Charles Czeisler, a scientist and sleep expert at Harvard Medical School, believes that caffeine causes us to lose sleep, which he says is unhealthy. "Without adequate sleep—the typical eight hours—the human body will not function at its best, physically, mentally, or emotionally." Too often, Czeisler says, we consume caffeine to stay awake, which later makes it impossible for us to get the rest we need. Health risks have also been tied to caffeine consumption. Over the years, studies have attributed higher rates of certain types of cancer and bone disease to caffeine consumption. To date, however, there is no proof that caffeine actually causes these diseases.

阅读6A 世界上最受欢迎的药物 现在是凌晨1点45分，21岁的托马斯·墨菲正在熬夜， 今天下午2点，他将参加一场重要的工程考试。 为了保持清醒和警觉，他在过去的三个小时里喝了两杯咖啡 现在正在喝一种流行的能量饮料-- 它的咖啡因含量是一罐类似大小的苏打水的两到三倍。 许多像墨菲这样的学生，以及马拉松运动员、航空公司飞行员和长途旅行者， 它们的能量归功于人类最古老的兴奋剂之一： 咖啡因。 对抗身体疲劳和提高警觉性的力量 这也是咖啡因被列为世界上最受欢迎的情绪调节药物的部分原因。 它不仅存在于苏打水、能量饮料、咖啡和茶中，也存在于减肥药中， 止痛药（如阿司匹林）和巧克力棒。 世界各地的许多社会也围绕咖啡因的使用创造了完整的仪式。 例如，有法国的咖啡文化，日本的茶道， 在许多文化中，早晨的一杯咖啡或茶标志着一天的开始。 咖啡因存在于我们消费的许多食物和饮料中，但它对我们有好处吗？ 哈佛医学院的科学家和睡眠专家Charles Czeisler认为，咖啡因会导致我们失眠， 他说这是不健康的。 “如果没有充足的睡眠——典型的八个小时——人体将无法在身体、精神或情感上发挥最佳作用。” Czeisler说，我们经常摄入咖啡因来保持清醒， 这后来使我们无法得到所需的休息。 健康风险也与咖啡因的摄入有关。 多年来，研究将某些类型的癌症和骨病的发病率较高归因于咖啡因的摄入。 然而，迄今为止，还没有证据表明咖啡因确实会导致这些疾病。

A number of scientists, including Roland Griffiths—a professor at the Johns Hopkins School of Medicine in the United States— believe that regular caffeine use causes physical dependence. Heavy caffeine users, Griffiths says, exhibit similar behaviors. For example, their moods fluctuate from high to low, they get mild to severe headaches, or they feel tired or sad when they can't have a caffeinated drink. To minimize or stop these feelings, users must consume caffeine—a behavior Griffiths says is characteristic of drug addiction. Despite these concerns, the general opinion in the scientific community is that caffeine is not dangerous when consumed in moderation. This means having one or two small cups of coffee (about 300 milligrams of caffeine) per day, for example. Furthermore, a lot of current research contradicts long held negative beliefs about caffeine, and suggests that it may, in fact, have health benefits. For instance, studies have shown that caffeine can help ease muscle pain. Because it is a stimulant, caffeine can also help improve one's mood. Research has also shown that some caffeinated drinks—specifically certain teas—have disease-fighting chemicals that can help the body fight a number of illnesses, including certain types of cancer. In addition, as a type of mental stimulant, caffeine increases alertness, memory, and reaction speed. Because it fights fatigue, it facilitates performance on tasks like driving, flying, and solving simple math problems. And while it is true that caffeine can increase blood pressure, the effect is usually temporary and therefore not likely to cause heart trouble. This is especially true if caffeine is consumed in moderation. Moreover, despite its nearly universal use, caffeine has rarely been abused. "With caffeine, overuse tends to stop itself," says Jack Bergman, a specialist at Harvard Medical School. If you consume too much, "you get ... uncomfortable, and you don't want to continue." Caffeine's behavioral effects are real, but most often mild. Getting that burst of energy, of course, is why many of the world's most popular drinks contain caffeine. Whether it's a student drinking coffee before class or a businessperson enjoying tea with lunch, humankind's favorite stimulant is at work every day, all over the world.

许多科学家，包括美国约翰霍普金斯医学院的罗兰·格里菲斯教授-- 相信经常摄入咖啡因会导致身体依赖。 格里菲斯说，大量摄入咖啡因的人也表现出类似的行为。 例如，他们的情绪从高到低波动，他们会出现轻度到重度的头痛， 或者当他们不能喝含咖啡因的饮料时，他们会感到疲倦或悲伤。 为了尽量减少或阻止这些感觉，用户必须摄入咖啡因——格里菲斯说，这种行为是毒瘾的特征。 尽管存在这些担忧，但科学界的普遍观点是，适量摄入咖啡因并不危险。 例如，这意味着每天要喝一到两小杯咖啡（约300毫克咖啡因）。 此外，目前的许多研究与长期以来对咖啡因的负面看法相矛盾， 并表明它实际上可能对健康有益。 例如，研究表明，咖啡因可以帮助缓解肌肉疼痛。 因为咖啡因是一种兴奋剂，它也有助于改善一个人的情绪。 研究还表明，一些含咖啡因的饮料，特别是某些茶，含有抗病化学物质 它可以帮助身体对抗多种疾病，包括某些类型的癌症。 此外，作为一种精神兴奋剂，咖啡因可以提高警觉性、记忆力和反应速度。 因为它可以对抗疲劳，所以它有助于提高驾驶、飞行和解决简单数学问题等任务的表现。 虽然咖啡因确实会增加血压， 这种影响通常是暂时的，因此不太可能引起心脏病。 如果适量摄入咖啡因，尤其如此。 此外，尽管咖啡因几乎被普遍使用，但很少被滥用。 哈佛医学院专家杰克·伯格曼说：“过量摄入咖啡因往往会自行停止。”。 如果你吃得太多，“你会……不舒服，你不想继续下去。” 咖啡因的行为影响是真实的，但通常是温和的。 当然，获得这种能量是世界上许多最受欢迎的饮料含有咖啡因的原因。 无论是学生在课前喝咖啡，还是商人在午餐时喝茶， 人类最喜欢的兴奋剂每天都在世界各地发挥作用。

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