氧化胆固醇导致阿尔茨海默病
本视频由Michael Greger医生于 2018 年 5 月 30 日发布，来自NutritionFacts.org — 能救命的营养学。
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》，于今年5月底出版。
氧化胆固醇导致
阿尔茨海默病
Oxidized Cholesterol as a Cause of Alzheimer’s Disease
摘要：氧化胆固醇的毒性可能比普通胆固醇高100倍，这引发了对酥油，金枪鱼罐头，加工肉类和巴马干酪等食品的额外担忧。
Oxidized cholesterol can be 100 times more toxic than regular cholesterol, raising additional concerns about foods such as ghee, canned tuna, processed meat and parmesan cheese.
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长久以来，人们一直认为血液中过多的胆固醇是导致阿尔茨海默病的主要危险因素，可能还有帕金森病。
Too much cholesterol in the blood “has long been considered to act as a primary risk factor for developing Alzheimer’s disease and, possibly, Parkinson’s disease.”
我已经展示过这些大脑动脉的惊人图像是来自阿尔茨海默患者的解剖图，被脂肪和胆固醇堵塞，与非老年痴呆者相比。
I’ve shown these striking images of what the brain arteries of Alzheimer’s victims look like on autopsy, clogged with fat and cholesterol, compared to non-demented elderly controls.
但是，等等：胆固醇不能直接穿过血脑屏障而进出大脑，所以它不能直接进入，也不能直接排出大脑。
But wait a second: “cholesterol cannot be directly exported across the blood-brain barrier.” So, it can’t directly get into the brain, or out of the brain.
如果大脑含有过多的胆固醇并需要排出一些，该怎么办呢？
What if the brain has too much cholesterol, and needs to get rid of some?
作为一种安全阀，大脑中有一种能够氧化胆固醇的酶。而胆固醇以这种氧化的形式排出大脑并最终排出身体。
As a safety valve, there’s an enzyme in the brain that oxidizes the cholesterol. And, in that form, it can exit the brain, and eventually the body.
啊，但这是想不到的：“尽管这样意味着大脑可以消除多余的胆固醇”，这些氧化产物却可以双向流动。它可能“允许一些在血流中存在的有毒氧固醇 - 氧化胆固醇 - 进入并积聚在大脑中。”
Ah, but here’s the kicker. “Although this fact means that the brain can eliminate excess amounts of these oxidation products,” it could be a two-way street. It could “allow toxic amounts of oxysterols - oxidized cholesterol - present in the blood stream to go the other way, and accumulate in the brain.”
这不仅仅是理论层面的担忧。
This is not just a theoretical concern.
这项严谨的研究表明，通过测量氧化胆固醇从大脑中流出进入血液中的水平，在颈部颈静脉测量，与通过动脉进入大脑的水平相比，可以衡量差异。
This elegant study showed that by measuring oxidized cholesterol levels in the blood coming off the brain, measured in the jugular vein in the neck, compared to the levels going into the brain through the artery, you could measure the difference.
这表明如果有太多的氧化胆固醇在血液中，它可能会积存在大脑中。
And, this shows if you have too much oxidized cholesterol in your bloodstream, it can end up in your brain.
这会造成问题，因为“氧固醇的积累可致细胞毒性，致突变，致动脉粥样化，可能致癌” - 换句话说，对细胞有毒，对DNA有毒，并导致心脏病和可能导致癌症。
This is a problem, because “the accumulation of oxysterols can be cytotoxic, mutagenic, atherogenic, and possibly carcinogenic” — in other words, toxic to cells, toxic to DNA, and contributing to heart disease and maybe cancer.
是的，来自动脉粥样硬化斑块的尸体解剖标本含有比正常动脉多20倍的胆固醇，但含有高达45倍的氧化胆固醇水平。
Yes, samples from atherosclerotic plaques on autopsy contain 20 times more cholesterol than normal arteries, but they contain 45 times higher levels of oxidized cholesterol.
胆固醇氧化产物可能比未氧化的胆固醇病态及毒性强至 100 倍以上，不仅导致心脏病，而且可能导致多种不同的重大慢性病，包括阿尔茨海默。
Cholesterol oxidation products may be up to 100 times more pathological, more toxic than un-oxidized cholesterol — contributing to not only heart disease, but potentially a variety of different major chronic diseases, including Alzheimer’s.
好的，那怎样才能减少体内这些氧固醇含量呢？
Okay, so how can we cut down on the amount of these oxysterols in our body?
一种方法，是不吃含氧化胆固醇的东西。
One way is by not eating them.
氧化胆固醇存在于“奶粉，肉和肉制品中（包括鱼），奶酪，鸡蛋和蛋制品。”
Oxidized cholesterol is found in “milk powders, meat and meat products (including fish), cheese, and eggs and egg products.”
先前的理解受到了缺乏测试方法的限制无法准确地分析氧化胆固醇在各种食物中的量，但现在已经有方法了。
Until recently, our understanding had been limited by the lack of testing methods to accurately analyze the amount found in various foods…until, now.
在所有动物制品中都可以找到氧化胆固醇。
Oxidized cholesterol found throughout animal products.
罐装金枪鱼含量惊人地高，但酥油中的最多。
Canned tuna was surprisingly high, but ghee takes the cake.
酥油，又名澄清黄油、煮黄油，通常用于印度烹饪。
Ghee, clarified butter, boiled butter, is commonly used in Indian cooking.
这种食物处理方法会使氧化胆固醇水平增加十倍。
The method of preparation appears to multiply oxidized cholesterol levels tenfold.
这种饮食中的氧化胆固醇可有助于解释为什么印度饱受心脏病摧残，即使有显著比例的人口不吃肉和鸡蛋。（许多印度乳制品甜点也是以类似的方式制作的。）
This dietary exposure from oxidized cholesterol may help explain why the subcontinent of India is ravaged by such heart disease, even though a significant proportion of the population stays away from meat and eggs. (A number of Indian dairy-based desserts are also made in a similar way.)
饮食中的氧化胆固醇是人类血液中氧化胆固醇的一种来源，它可以很容易地穿过血脑屏障进入大脑，这可能会引发大脑内的炎症，淀粉样物质的积聚，这些都发生在“记忆损伤诊断前的数年。”
Oxidized cholesterol in the diet is a source of oxidized cholesterol in the human bloodstream, where it can then readily cross the blood-brain barrier into the brain. And this could trigger inflammation inside the brain — the buildup of amyloid — all occurring “years before the impairment of memory is diagnosed.”
这些早期研究显示血液中氧化胆固醇的积累来自那些饱含氧化胆固醇的膳食，吃下几个小时后，血液中会出现这种尖峰，鸡蛋粉也是这样，这在很多加工食品中存在，但通常不会单独拿来吃。
These early studies, showing the buildup of oxidized cholesterol in the blood of those fed meals rich in oxidized cholesterol, where you get this spike in your bloodstream a few hours after you eat, were done with things like powdered egg, which can be found in a lot of processed foods. But, you typically don’t sit down to a meal of it.
尽管如此，从正常食物摄取也会有同样的结果。给人吃一些意大利腊肠和巴马奶酪，天然饱含胆固醇氧化产物，其在当天晚些时候在整个身体中循环。
You get the same thing, though, from eating normal food sources. Give folks some salami and parmesan cheese, which are naturally rich in cholesterol oxidation products, and later that day, it’s circulating throughout their bodies.
而更高的水平不仅与轻度认知障碍相关，阿尔茨海默症也是如此。
And, higher levels are not only associated with mild cognitive impairment, but Alzheimer’s disease as well.
“脑中浓度的增加可能促进细胞损伤，引起神经细胞功能障碍，退化，可能导致神经炎症”（脑部炎症），并形成这些淀粉样物质斑块。
“Increased concentrations in the brain may promote cellular damage, cause nerve cell dysfunction and degeneration, and could contribute to neuroinflammation” (brain inflammation) and the formation of these amyloid plaques.
在培养皿中就可以观察到炎症基因表达的增强。
You can show the boost in inflammatory gene expression right in a petri dish.
在体外培养人类神经细胞，并滴上少许胆固醇，培养皿中的细胞会发炎，但加入相同量的氧化胆固醇，则会变得更糟。
You can grow human nerve cells in vitro and drip a little cholesterol on, and you get a bump in inflammation. But, add the same amount of oxidized cholesterol, and it gets much worse.
如果从阿尔茨海默病的尸检中看看不同阶段脑氧固醇的变化，可以看到三种主要胆固醇氧化产物是如何积聚的。
And, if you look at the changes in brain oxysterols at different stages of Alzheimer’s disease on autopsy, you can see how the three main cholesterol oxidation products appear to be building up.
阿尔茨海默患者大脑中的水平显示出急剧增加，为以下说法增添了证据：“氧化胆固醇可能驱使阿尔茨海默病的发展。”
Levels have been shown to dramatically increase in Alzheimer’s-disease brains, adding to the evidence that “oxidized cholesterol may be a driving force behind the development of Alzheimer’s disease.”
（翻译及字幕制作：老玉米 Karen Chou)
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译者后记：
阿尔茨海默病与老年痴呆并非完全等同，阿尔茨海默病是造成老年痴呆的最常见的原因。阿尔茨海默病人都患有老年痴呆，但是只有一部分患老年痴呆的人得阿尔茨海默病。
阿尔茨海默病与老年痴呆的区别：
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去年夏天回国时见到父亲，他连身边天天能见到面的亲人都不认识啦。他就是典型的老年痴呆病患者。
和母亲离婚后，他一个人生活，经常买街边油炸的东西吃，终于吃出了脑梗，进而老年痴呆。
曾经找不到回家的路，害得大冬天，我哥、嫂，还有我80多岁的老妈满大街找他，还好最后都找到了。后来请了一位男保姆，一天24小时看着他。男保姆人很好，一看就是两年。
去年夏天我回国时见到父亲，故意问他：“爸，你知不知道我是从哪来的？” 他马上回答说：“你是从天上掉下来的。” 回答时手还指向天。从逻辑上讲回答是没问题的。平时还可以看书、读报。但就是不认识人啦。
今年春节过后，男保姆突然辞职啦，家里儿媳妇生孩子，有事忙不过来。
于是，哥哥给父亲找了一家养老院，他一个人住单间，条件还不错，每月费用差不多5000，这在河南洛阳算是不少的费用，不过父亲的退休工资还是可以支付的，但到了养老院不到三天时间就出事啦！
养老院说父亲在吃早餐时噎到了，马上送医院抢救也无力回天，享年83岁。
跟养老院一起购买的保险三天后生效，父亲去世时还差几小时不到三天，因此保险公司也不负责。
父母的四个孩子中只有我一人在美国，孩子们要上学，事发突然，我也没能回国送父亲最后一程。没想到去年夏天就是最后一面。
母亲快85周岁啦，在我影响下吃素好几年了，身体还不错，去年回国给我看她的体检表，血液各项指标全部合格，吃素后她的体重由原来的130多斤自然减到110斤的标准体重，原来血液粘稠，现在也正常啦。
科技发达，我虽人在美国，但每天都跟母亲用微信视频，母亲思维清晰，《圣经》上的小字，不戴眼镜也能看清。
愿父亲在天堂安息！
愿母亲福如东海、寿比南山！
愿天下没有病痛！
老玉米这个月底要回国看望母亲，现在加紧时间多翻译一些文章，争取回国期间还可以照常更新。现在的发文频率基本上每星期两篇。
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