视频文本

Moving on to the last sub-topic in this presentation.
下面我们来看本讲的最后一个话题
Do organic foods prevent cancer better than conventional foods?
有机食品是否比传统食品具有更强的防癌功效?
No one credible study has indicated any benefit;
没有任何权威研究可以证明这一点，
though studies do show a certain nutritional advantage of some components of fruits and vegetables.
尽管一些研究确实显示一些水果和蔬菜确实有额外的营养功效
Let's look at a recent study concerning the antioxidant benefits of tomatoes.
我们来看一个最近的实验，是关于番茄的抗氧化效果的
In 2003, a study by French researchers sought to determine the antioxidant benefits of organic versus conventional tomatoes.
2003年法国研究人员想要研究有机番茄和传统番茄在抗氧化方面的效用有何差异
Using a study group of 20 nonsmoking females between the ages of 21 to 39 years,
研究人员对20名21-39岁的不吸烟的女性进行试验
the researchers compared the antioxidant micro-constituent contents between organically and conventionally grown tomatoes
研究人员比较了有机和传统番茄中的抗氧化成分的水平
and to evaluate whether the consumption of purees made of these tomatoes
然后让实验对象每天分别服用由这两种番茄制成的番茄酱，
could differently affect the plasma levels of antioxidant micro-constituents in humans.
最后研究它们会对人体内血浆中的抗氧化成分造成哪些影响
It was discovered that the variety of fresh organic tomatoes used had higher vitamin C,
实验结果表明，与传统番茄相比，除了绿原酸之外，
carotenoids, and polyphenol contents except for chlorogenic acid than conventional tomatoes.
有机番茄中的维生素C类胡萝卜素和多酚含量都更高，
In tomato purees, concentrations of Vitamin C and polyphenols
制成番茄酱后，有机番茄中的维生素C和多酚含量
remained higher than purees made out of conventional tomatoes.
依旧高于传统番茄制作的番茄酱
However, for the nutritional intervention,
在三周内，两组实验对象每天都分别
no significant difference after three weeks of consumption of 96 grams per day approximately one half cup of tomato puree
食用96克番茄酱，也就是半杯，但三周后，结果显示，
was found between the two purees with regard to their ability to affect the plasma levels of the two major antioxidants, Vitamin C and lycopene.
两组实验对象血浆中的两种主要的抗氧化剂，也就是维生素C和番茄红素都没有很大变化，因此有机和传统食品在营养作用上并没有显著差别
What do you think? Answer true or false to the following.
大家对此有何看法? 请大家对下列问题回答是或否，
Organic food is more nutritious than conventional food.
有机食品是否比传统食品更加有营养?
And, organic food is safer than conventional food.
有机食品是否比传统食品更加安全?
Now that you've seen some of the big issues relating to organic and conventional foods,
我们已经看了几个与有机食品和传统食品相关的重要问题，
you probably have some questions on whether or not organic produce is worth the extra cost.
大家或许会问花更高的价格购买有机食品是否值得
According to the Whole Foods Market Survey we discussed earlier,
根据我们之前讨论过的天然食品市场调查
67% of people who buy organic foods do so because they feel organic foods are healthier.
购买有机食品的人中67%的人是因为他们认为有机食品更加健康
There is a wide spread belief that organic food is healthier,
人们普遍相信，有机食品更加健康
most likely due to the principles associated with organic farming.
这或许和有机农业的几个原则有感
Organic farming practices largely avoid synthetic fertilizers,
有机农业在生产过程中要避免使用合成化学肥料
pesticides, growth regulators, and livestock feed additives.
杀虫剂，以及饲料添加剂
Organic farming systems rely on crop rotations, manures, organic waste,
有机农业系统通过谷物发酵粪便，有机排泄物
and biological pest controls to maintain soil productivity,
和利用生物方法防治病虫害来保证土壤肥力
supply nutrients to growing plants, and control pests.
给作物提供营养和进行病虫害防治
However, organic farming regulations differ across countries and between certifiers.
但是有机农业的具体规定和监管在各国都是不同的，
The non-use of synthetic chemicals remain part of the allure of the organic movement
不用化学合成的化肥农药依旧是有机食品广受欢迎的原因，
and underlie consumer belief that organic food is virtually free of the hazards found in chemical produce.
也就是说，消费者相信有机食品中不含化学品种的危险物质

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。