原文视听

Purple grape juice has twice the natural antioxidant level.
紫葡萄汁含有两倍的天然抗氧化剂
Food companies competed over
食品生产商为谁的产品
whose product contained the most.
含最多抗氧化剂而竞争
Creams containing antioxidants
含有抗氧化剂的面霜
spawned a multi-billion pound beauty industry.
兴起了几十亿元的美容产业
Dramatic results around the eyes.
眼周发生惊人改变
Scientists no longer think it's about heart beats,
科学家不再认为心跳速率是其中关键
but oxygen is still at the centre of this major theory.
取而代之 氧气成了这个学说的核心
One of the important components of all living organisms
生物所具有的共同特点之一是
is the need for oxygen,
对氧气的需求
and the reason we need oxygen is that we use oxygen
我们需要氧气产生能量
to essentially generate energy so that we can live.
维持生命
And so when we take that oxygen in and we burn it,
当我们吸入氧气并消耗时
we have one of the by products that comes from this,
我们并不仅仅得到能量
not only do we get the energy
同时也获得了此过程的副产品
but we also have radicals or oxidative stress.
自由基或者氧化应激
All of life actually is, you have these trade-offs
所有生命体都通过这种交易
to get this energy,
来获得氧气
you've essentially had to pay a price but...
你最终要付出代价
and the price from the oxidative stress theory of ageing,
根据氧化应激致衰老学说
the price would be that you're eventually going to age.
最终的代价是衰老

重点解释

Scientists no longer think it's about heart beats,科学家不再认为心跳速率是其中关键

no longer:不再

He is no longer within the pale of noble society.

他不再是贵族社会的一员了。

He weeded out the books he no longer needed.

他把不再需要的书清理出去了。

we use oxygen to essentially generate energy so that we can live.我们需要氧气产生能量维持生命

so that:因此； 以至于； 以便

Bring it closer so that I may see it better.

把它拿近点儿，让我看看仔细。

Let down a rope so that I can climb up.

放下绳子，让我爬上去。

词汇拓展:

so far as that goes就现状来说(就其本身而言)

So far as that is concerned, you must have understood my determination.

谈到这里,你一定已经明白我的决心。