如何通过饮食降低体内重金属含量

原创能救命的营养学蔬食益生

本视频由格雷格（Michael Greger）医生于 2018 年 6 月 25 日发布，来自NutritionFacts.org — 能救命的营养学。

专家太多，什么样的研究才是靠谱的？(点击了解，你会震惊！）

格雷格（Michael Greger） 医生是畅销书《How Not to Die》作者，中文译本：繁体版书名为《食疗圣经》。简体版书名为《救命》，已于今年7月19日发售，详情见文末。

如何通过饮食降低

体内重金属含量

How to Lower

Heavy Metal Levels with Diet

视频摘要：什么样的饮食改变可以同时帮助身体排除汞、铅和镉之毒？

What dietary change can simultaneously help detoxify mercury, lead, and cadmium from the body?

我们之前已经探讨过如骨粉之类的钙质补充剂中含有铅污染的问题，但其实不只是骨粉。

We’ve previously explored the issue of lead contamination in calcium supplements like bonemeal, but it wasn’t just bonemeal.

在一些更常见的非处方补充剂中也发现大量的铅

Substantial quantities of lead were found in other, more common, over-the-counter supplements.

而测试仍持续引起骨粉对公众健康影响的关注，但幸运的是骨粉现在已不那么普遍了。

Still, testing revealed continued public health concern over bonemeal, but thankfully it’s not as popular these days.

所以我们多数已经不太可能直接曝露于骨粉的铅危机当中，但却可能通过我们吃的动物而间接暴露于铅的危机中。

So, most of us are not likely to get directly exposed to the lead in bonemeal any more, but we may get indirectly exposed through the animals we eat.

在美国，屠宰场每年会产生五十亿磅肉和骨粉的副产品。

In the U.S., five billion pounds of meat and bonemeal are produced as slaughterhouse by-products every year.

我们每年如何处理这好几百万吨的副产品？

What do we do with these millions of tons every year?

我们把它喂回去给农场动物，尤其是鸡。而大部分骨粉中的铅都会经过动物体内直接排放到粪便里，但我们却又把那些粪便（牛、猪和鸡粪）再次喂给动物。

We feed it back to farm animals, particularly chickens. Now, most of the lead in the bonemeal passes right through the animals into their waste, but then we take that waste (cow, pig, and chicken feces) and feed it back to the animals again.

你猜对了！所以你可以看到污染物如何在牠们的体内累积

You guessed it! So, you can see how the levels of contaminants might build up in their bodies.

我以前曾经谈过若是这样的话煮鸡汤之类的会意味着什么，但对于这类喂食方式就是把牛喂给牛、猪和鸡，最初的担忧是朊病毒疾病的传播，例如疯牛病。

I’ve talked previously about what that might mean for making something like chicken soup, but the original concern about these kinds of feeding practices, feeding cows to cows, and pigs and chickens, was the spread of prion diseases, like mad cow disease.

但这种循环所扩大的不只是朊病毒，还有其他有毒物质，包括铅。

But it’s not just prions that this kind of recycling can magnify, but other toxic substances, including lead.

所以偏向植物性的饮食可能可以降低我们曝露于铅的机率，而更多的植物性饮食理论上可更有效降低暴露于铅的机率。但你必须进行测试。

So, a more plant-based diet may be able to lower lead exposure, and an even more plant-based diet could theoretically lower exposure even more. But you’ve got to put it to the test.

可是，我们应该期望能找到益处吗？

But should we expect to find a benefit?

是的，铅是肉类中的毒素之一，但我们在饮食中的铅有一半大概是来自植物性食物

Yes, lead is one of the toxins found in meat, but half of our dietary exposure probably comes from plant foods.

欧洲的饮食模式研究显示素食者所接触到的铅含量与一般大众约莫相同，唯一例外的是吃大量野味的人可能会接触到比其他大部份食物多上一千倍的铅含量。

Dietary modeling studies in Europe suggest that vegetarians would be exposed to about the same amount of lead compared to the general population, with the exception of those who eat a lot of wild game, which can end up with a thousand times more lead than most other foods.

事实上，素食（蛋奶素）的铅含量甚至可能更高。但是，这不是关乎于你吃什么；而是你吸收到什么。

In fact, a vegetarian diet may even be higher in lead. But, it’s not what you eat; it’s what you absorb.

正如我们从镉的故事中了解到的，从动物来源的食物中摄取到人类肠壁细胞内的有毒重金属可能高于来自蔬菜来源的食物。

As we learned from the cadmium story, the uptake of toxic heavy metals from animal food sources into human intestinal lining cells may be higher than from vegetable sources.

这就是为何你会看到一位素食者的血液中铅和镉的浓度非常低，但她饮食中的铅和镉浓度却较高。

That’s how you have a vegetarian with some of the lowest concentrations of lead and cadmium in her blood, despite higher concentrations in her diet.

但你不知道真相如何，直到你......进行测试。

But you don’t know, until you…put it to the test.

随着饮食改变为素食我们似乎能透过排便排出更多的铅，研究中有九位实验对象的铅排出平均提升了三倍，有三位未受影响，有四位下降了大约一半。

There seemed to be a tendency towards higher fecal elimination of lead following a change to a vegetarian diet, with nine subjects on average tripling their elimination of lead, three unaffected, and four dropping by about half.

但是，这项研究只持续了几个月，所得出的差异在统计学上并无太大意义

But the study only lasted a few months, and the difference wasn’t statistically significant.

所以，让我们来尝试一年

So, let’s try a year.

将饮食转为大量的生蔬菜、水果、未精制食物、全谷物，并排除肉类、家禽、鱼类和蛋类（但它仍然包含发酵乳制品，类似一种酸奶）以及削减加工食品和垃圾食物。

A shift towards a diet characterized by large amounts of raw vegetables, fruits, and unrefined foods, whole grains, with the exclusion of meat, poultry, fish, and eggs (though it did include fermented dairy, like a type of soured milk), as well as cutting back on processed foods and junk.

他们在饮食转变的前后都剪下头发做测试，并发现显著地减少了重金属，包括将他们的铅水平降低将近一半。

They took clippings of hair before and after the shift, and got significant reductions in heavy metals, including cutting their lead level nearly in half.

看看这个：这是在开始的时候从他们的体内渗入头发的汞、镉和铅，而在三个月内，他们的有毒重金属下降了，并停留在低水平。

Check this out: this is how much mercury, cadmium, and lead they had oozing from their body into their hair when they started, and within three months, their toxic heavy metal levels went down, and stayed down.

我们怎么知道这不是纯属巧合？

How do we know it wasn’t just a coincidence?

因为数字回升了就在研究结束后过了几年，当他们回到自己平常的饮食，他们的汞、镉和铅水平又回升到以前的数值。

Because they went back up a few years later after the study was over, after they went back to more of their regular diet, and their mercury, cadmium, and lead levels shot back up to where they were before.

另一研究组结束后两年也有相同情形。

Same thing with a different group after two years.

汞的下降很容易解释，可能是由于对鱼类的摄取急剧下降，而减少酒精饮料的摄取可能是导致铅下降的原因，但这也可能是类似镉的效应，也就是头发的铅含量下降可能是由于饮食的转变而导致身体本身减少对铅的吸收。

The drop in mercury is easy to explain, presumably due to the drastic drop in fish consumption, and the drop in alcoholic beverages may have contributed to the drop in lead, but it also could have been a cadmium-like effect, where the decrease in hair lead content could be due to the dietary shift resulting in less absorption of lead into the body in the first place.

翻译： Janet Chan

编辑： Karen Chou (老玉米)

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