【英语听和读】新兴的超级食品(在线收听

Jackie: Hello welcome to Entertainment! I'm Jackie Dalton. If you're someone
who is quite careful about what you eat and likes to be healthy, then you
might want to find out about what's being hailed as the latest super food.
A 'super food' is a term which we're hearing more and more these days to
describe food that's very good for you. So far, the 'super foods' category
has included blueberries, nuts, tomatoes and garlic. But new research has
found that yet another type of food deserves to be added to the list. And
that's watercress. Watercress is a small leafy green plant that grows in
water and tastes quite strong. It's often used in salads.
Ian Rowland
Watercress has been known for a long time to have beneficial properties.
Jackie: Ian Rowland is a Professor of Human Nutrition and has just done a study
that shows watercress is very good for us. As he just said, it has
'beneficial properties' - a term we often hear to describe things which are
good for our health - 'beneficial properties'. Watercress has been used for
medicinal purposes for many years… that's another expression: if
something is used 'for medicinal purposes' it's used to treat or to prevent
illness. So, since when is watercress known to have been used for
medicinal purposes? Listen to find out.
Ian Rowland
Watercress has been known for a long time to have beneficial properties. It's been
known since the times of the Greeks, the Ancient Greeks that it has been used for
medicinal purposes 
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Jackie: Did you get that answer? Watercress has been used for medicinal
purposes since the times of the Ancient Greeks – a very long time indeed!
Professor Rowland and his team carried out an experiment on volunteers
to see what effect eating watercress would have on them. Two questions
for you to answer this time: how many volunteers took part in the
experiment and how much watercress did they eat each day?
Ian Rowland
We recruited 60 volunteers, who ate a bag of watercress – one bag a day. And these
were a nice cross-section of people, they were 19 to 55 years old, they ate it for 8 weeks.
Jackie: Did you get those answers? They recruited sixty volunteers for the
experiment and they each had to eat a bag a day. Ian said they had a
cross-section of the population, which means it was a group of people
that was typical of the population as whole, with a range of ages,
lifestyles, races and so on.
BBC Learning English
Before we hear from Ian again, a few bits of language that might be
useful to you:
To analyse something – means to examine it very closely
A sample – a sample is a small part or amount of something that's
examined in order to find out something about the whole, doctors
sometimes look at blood samples to find out what is wrong with patients.
DNA – is a substance that carries information in the cells of the body and
controls how our bodies function and change.
Now try to answer this question: what did the researchers look for when
they analysed blood samples from volunteers? 
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Ian Rowland
We analysed the blood samples for the amount of DNA damage in the blood. And
DNA damage, we know, is an important process in the development of cancer.
Jackie: Did you get the answer? The researchers looked for damage to DNA.
Every day our DNA is damaged – that's part of our body's ageing process.
But it is possible to reduce DNA damage. In the experiment, the
researchers found two key things: what were the two things?
Ian Rowland
A decrease in the level of DNA damage in blood cells of those individuals and
furthermore, when we took those blood cells and treated them with a chemical which
caused DNA damage, they were more resistant.
Jackie: Did you get those answers? They found firstly that DNA damage
decreased - went down - in people eating watercress. They also found the
cells were more resistant to chemicals that are known to damage DNA –
they could defend themselves better against bad chemicals. Listen again.
 
Ian Rowland
A decrease in the level of DNA damage in blood cells of those individuals and
furthermore, when we took those blood cells and treated them with a chemical that
caused DNA damage, they were more resistant.
Jackie: So all this suggests that watercress is good at protecting our bodies and
may help us fight against things like cancer. But that's not the only
reason to eat watercress. Tom is a British chef. He is glad watercress has
become part of what he calls the 'super food clique' – a clique is a kind
of special club or group that is not always very easy to get in to. As Tom
points out, there are other things that, at least for people in Britain, make
watercress a good choice. What are they? Try to list at least three. 
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Tom
I'm delighted with this piece of research. It's really nice to see a food sort of enter the
super food clique that's grown in Britain, largely, and all year round it's available… so
it's not like air freighted blueberries, it does taste good, and it's very versatile.
Jackie: Did you catch any of those reasons? Tom says watercress is always
available - it's grown all year round, it tastes good and it's versatile,
which means it can be used in lots of different ways. He points out that
watercress in Britain isn't air freighted, which means it's not flown in
from other countries on a plane because it's grown in Britain.
That's all for this week and if you're not already a watercress eater
perhaps, if you can get it where you are, it's worth trying it out. 
  原文地址:http://www.tingroom.com/lesson/yythd/404769.html