视频文本
Caffeine stimulates the central nervous system.
咖啡因刺激中枢神经系统
It makes you more alert and boosts energy.
它使你注意力集中，激发能量
For these reasons it is used in man over the counter
因此，它像伊克赛锭止头痛药一样
pain relievers such as Excedrin Migraine.
被用作非处方镇痛药物
How much caffeine is considered safe to consume?
摄入多少咖啡因是安全的呢?
There are no standards for caffeine consumption
没有明确的标准
however a range of 500 to 600 mg per day
但是每天摄入500到600毫克
is considered to be safe.
被认为是安全的
This would be around 4 to 7 cups of strong coffee,
这个量相当于喝4到7杯浓咖啡
three to four grande Starbucks vanilla lattes,
3到4大杯星巴克香草拿铁
9 to 11 cans of Mountain Dew
9到11罐激浪
or 6 to 8 small cans of Red Bull.
或者6到8小罐红牛
Very high caffeine consumption
摄入过多咖啡因
has serious impacts on health including
对健康有严重影响
restlessness, anxiety, irritability and headache.
这包括烦躁不安，焦虑，易怒，及头痛
Some people may be very sensitive to caffeine intake
一些人可能对咖啡因摄入很敏感
and need to limit their consumption
需要限制咖啡因摄入量
to avoid feeling jittery or anxious.
以避免紧张不安或焦虑
It is also possible to develop a sort of tolerance
不过也可能产生一种对咖啡因的耐受性
or dependency on caffeine.
或依赖性
And sudden reduction in intake
咖啡因摄入量的骤减
may cause headaches or withdrawal like symptoms.
可能导致头痛或类似药物戒断的症状
These are typically mild and short lived
这些症状通常较轻微，并且短暂
as the body adapts to a lower caffeine intake.
随着身体调整适应了更低的咖啡因摄入量
There are many factors that affect
有许多因素影响着
the amount of caffeine each individual can consume
每个人的最大咖啡因摄入量
before facing the negative side effects.
超过这个量，就会对身体产生副作用
Caffeine sensitivity is different depending on
对于咖啡因的敏感性会
body mass, age, smoking habits,
因体重，年龄，吸烟习惯
drug or hormone use and stress.
服用药物或荷尔蒙的摄，和压力的不同而不同
Individuals should monitor their caffeine intake
每个人应该留心自己的咖啡因摄入量
and adjust the amount to find a good balance.
并且加以调整以达到一个好的平衡状态
Several studies have examined the association
人们对于
between the consumption of
饮用
carbonated soft drinks containing caffeine
含咖啡因碳酸软饮料
and cancer risk.
和癌症患病几率之间的联系做了几项研究
The Harvard research team mentioned earlier
之前提到的哈佛研究小组
also examined the effects of soft drinks
也研究了碳酸饮料
on upper gastrointestinal cancers
对上消化道癌症的影响
and found no increased or decreased risks
发现每天一罐或者更多的碳酸饮料对对增加或降低
of cancer of the mouth, pharynx,
口腔，咽
larynx, esophagus or stomach
喉，食道或胃部的癌症发病率
with consumption of 1 or more cans per day.
没有影响
Because many of the soft drinks
由于美国很多碳酸饮料
consumed in the US contain sugars
含糖
there is potentially an increased risk
也会潜在地增加
associated with cancers of the breast and colon
一些喝这些饮料的人
in persons consuming these beverages
患乳腺癌和结肠癌的几率
due to increased body fatness. However,
因为(糖)容易导致身体肥胖，但是
when examined separately from body fatness
当把碳酸饮料的影响与肥胖的影响
consumption of soft drinks
分开研究时
does not appear to increase the risk of cancer.
碳酸饮料并没有增加患癌症的几率
Coffee, tea and other caffeinated beverages
咖啡，茶，及其他含咖啡因的饮品
do not appear to increase
看起来不会增加
the risk of any forms of cancer
任何癌症的患病几率
and in fact may provide
而实际上可能
a protective effect on some forms of cancer.
对某些癌症有抵抗预防作用
Caffeine containing beverages, coffees and teas,
含咖啡因的饮料，咖啡，茶
are widespread in the marketplace.
在市场上到处都是
Children and teens are increasingly
儿童和青少年在越来越多地饮用这些产品
consuming these products at younger ages.
而且(开始饮用的)年纪越来越小
These products may contain high amounts of sugar
这些产品的糖含量可能很高
and low amounts of the beneficial compounds
而在咖啡或茶叶中发现的有益成分
found in coffee or tea.
含量却很少
It is always wise to read labels carefully
人们需要仔细阅读标签
and to monitor sugar and caffeine consumption
控制糖和咖啡因的摄入量，长期这样做是很明智的
especially in children.
尤其是对儿童来说
The impact of lifelong exposure to caffeine
至今还没有对终身摄入咖啡因的影响
has not been assessed.
进行评估
However caffeine has been consumed
然而自古以来人类
by humans throughout history.
就摄入咖啡因
Further research will be needed
我们需要进一步的研究
to more fully understand the many compounds
去更全面地了解
found in coffee and tea
咖啡和茶里发现的许多成分
and to identify their role in the cancer process.
并确认它们在癌症发展过程中的作用
Coffee and tea are clearly safe and enjoyable beverages
咖啡和茶显然是安全又好喝的饮料
that can be part of a healthy lifestyle.
可以成为健康生活方式的一部分

视频及简介

视频简介：

本课程的目标是，向公众提供最新的有关营养方面的信息和话题，内容涵盖饮食因素对于癌症的影响作用，健康的饮食习惯，学校能提供的营养有哪些，咖啡因与癌症的联系，水果蔬菜与癌症预防等。通过本课程的学习，人们可以学习到健康的生活饮食习惯，在每天的饮食中防癌症于未然