视频文本
The educated materials presented here
这里所用的教学材料
were developed by students and faculty
由爱荷华州立大学
of the Department of Food Science and Human Nutrition
食品科学与人类营养学系
at Iowa State University.
师生共同制作完成
Funding for this project was provided by grants
本项目的赞助资金来源于
from the American Cancer Society Midwest
美国中西部癌症学会
and the Lance Armstrong Foundation.
以及兰斯·阿姆斯特朗基金
The materials are intended for educational use
此材料仅供教育教学使用
and are not meant to provide medical advice.
不能作为医学指导
We welcome your feedback about these materials.
我们欢迎您有关本材料的反馈
Please use the evaluation survey link on the homepage
请登陆主页点击评估调查链接
to provide your comments and suggestions.
告诉我们您的意见和建议
Sodium: to salt or not to salt? Why talk about sodium?
钠:要用盐还是不要用盐?为什么要讨论钠?
Sodium is something that affects everyone, everyday.
钠与每个人的日常生活都息息相关
Everybody eats it and most people are unaware
人们每天都会摄入钠，大多数人却没有意识到
that they ingest far too much and are also unaware of
他们已经摄入了过量的钠，也没有意识到
the health implications of a high sodium diet.
高钠食品对健康意味着什么
Currently the government is trying to
目前政府正试图要求食品公司
push corporations to lower sodium in foods
在出售给消费者的食品中
available to consumers.
降低钠的含量
Sodium is an essential mineral
钠是一种非常重要的矿物质
which means it is vital for the human body.
这也意味着它对于人类身体健康意义重大
Chemically sodium is an electrolyte.
从化学意义上讲钠是一种电解质
Table salt is made up of both sodium and chloride.
餐桌上的盐则是氯化钠
Chloride is also an important nutrient.
氯化物也是一种重要的营养物质
But there's no major health concerns
但是在有关氯化物的摄入方面
related to consumption of chloride.
人们却没有特别的有关健康的忧虑
As stated earlier sodium is an electrolyte.
前面已经提到，钠是一种电解质
A normal balance of electrolytes is essential to
正常的电解质的平衡状态
the normal function of cells and organs.
对于细胞和器官的正常运转非常重要
Electrolytes help maintain voltages across
电解质有助于
cell membranes especially
维持细胞跨膜电压
in heart muscle and nerve cells.
尤其是心肌细胞和神经细胞
They also carry electrical impulses
它们还可以进行电脉冲
to create nerve impulses and muscle contractions.
来产生神经冲动和肌肉收缩
Kidneys work to
肾脏可以
keep the electrolyte concentrations in blood constant.
保持血液中的电解质浓度恒定
In simpler terms sodium helps
用简单的话来讲，钠有助于
maintain balance of fluids,
保持液体的平衡
helps transmit nerve impulses
有助于神经冲动的传递
and influences contraction and relaxation of muscles.
以及影响肌肉的收缩和放松
Many foods naturally contain sodium.
许多食品天然地含有钠元素
The main source of sodium in processed foods
加工食品中钠的来源
plays an integral role in
在食品加工和食品安全方面
food processing and food safety.
起着不可或缺的作用
It enhances the flavor of foods by masking bitterness
它通过掩盖苦和酸的味道
and acidity and has the ability to
来改善食品的口味
make sweets taste sweeter.
同时也可以使甜的味道更加浓烈
Salt regulates the fermentation of yeast
盐可以在烘培食品和酒精饮料中
in baked goods and alcoholic beverages.
调节酵母的发酵过程
It is useful in the manipulation of aroma,
它也有助于调节食品的香味
color and texture of food.
颜色和质地
The most important function of salt is
盐最重要的作用是
to preserve food and slow microbial growth
它有助于储存食品，减缓微生物生长速度
which extends the shelf-life of perishable items.
使易腐败食品延长保质期
The 2005 dietary guidelines for healthy adults is
2005年的健康成人膳食指南中推荐
2300 mg per day,
每天钠的摄入量为2300毫克
while the populations that are high risk
而高危人群的摄入量则仅为
should only consume 1500 mg.
1500毫克
The average American consumes 3500 mg daily,
普通美国人每天摄入量为3500毫克
more than 1000 mg above the recommended amount.
这一数值比推荐值高了1000毫克

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

重点讲解

重点讲解：
1.be unaware of 不知道；没有意识到；没意识到
例句：You seem to be unaware of how urgent the situation is .
你好象没有意识到形势是多么的急迫。

2.be vital for 对...至关重要的
例句：Mr. Sharon has said the disengagement is vital for Israel's security.
沙龙说，他的撤离方案对以色列的安全来说至关重要。

3.be made up of 由…构成；包含
例句：In modern western societies, a family group is usually made up of a man, his wife and his children.
在现代西方社会，一个家庭一般由丈夫、妻子和孩子组成。

4.have the ability to 有能力去；能够
例句：But if you ask me why and what? I am guess the "unrest brain part" might have the ability to receive other spatiotemporal informations.
如果你要问我为什么？我猜测“非休眠脑部分”，可能具有接收自其他时空的信息的能力。