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本视频由Michael Greger医生于2017年1月6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》一书作者，中文译本：繁体版书名为《食疗圣经》。简体版书名为《救命》，将于今年5月出版。 “什么原因导致胰岛素抵抗？” What Causes Insulin Resistance?
摘要：糖尿病前期和2型糖尿病是由归因于“肌内细胞脂质”的胰岛素敏感性下降引起的，即肌肉细胞内脂肪的积聚。 追溯至近一个世纪的研究，有一个引人注目的发现。 Studies dating back nearly a century noted a striking finding.
如果你把年轻健康的人分成两组，其中一半用高脂饮食，另一半用高碳水化合物饮食，这是仅在两天内发生的事情。在高脂饮食组中，葡萄糖不耐症会急剧上升。 If you take young, healthy people and split them up into two groups, half on a fat-rich diet, and the other half on a carb-rich diet, within just two days, this is what happens. The glucose intolerance skyrockets in the fatty diet group. 为了应对同样的糖水挑战，曾经狂吃脂肪组的后果是：血糖是原来的两倍。 In response to the same sugar water challenge, the group that had been shoveling in fat ended up with twice the blood sugar.
随着饮食中的脂肪含量升高，血糖水平也随之上升。 As the amount of fat in the diet goes up, so does one’s blood sugar spikes. 科学家需要将近七十年的时间解开这个谜团，但它最终会成为我们目前了解2型糖尿病病因的关键。 It would take scientists nearly seven decades to unravel this mystery, but it would end up holding the key to our current understanding of the cause of type 2 diabetes.
当比赛前运动员摄取碳水化合物时，他们试图在肌肉内建立燃料供应。 When athletes carb-load before a race, they’re trying to build up the fuel supply within their muscles.
他们将淀粉分解成消化道中的葡萄糖。 它以血葡萄糖 — 血糖循环，并被肌肉吸收，储存和燃烧获得能量。 They break down the starch into glucose in their digestive tract. It circulates as blood glucose — blood sugar — and is taken up by our muscles, to be stored and burned for energy.
然而，血糖就像一个吸血鬼。 它需要一个邀请才能进入我们的细胞。 而这个邀请就是胰岛素。 Blood sugar, though, is like a vampire. It needs an invitation to come into our cells. And, that invitation is insulin.
这是一个肌肉细胞。 这里有一些外面的血糖，耐心地等待进来。胰岛素是打开门让血液中的糖进入肌肉细胞的钥匙。 Here’s a muscle cell. Here’s some blood sugar outside, waiting patiently to come in. Insulin is the key that unlocks the door to let sugar in our blood enter the muscle cell.
当胰岛素与胰岛素受体结合时，它激活一种酶，再激活另一种酶，其再激活另外两种酶，最终激活葡萄糖转运，它充当葡萄糖进入细胞的入口。所以，胰岛素是打开肌肉细胞之门的钥匙。 When insulin attaches to the insulin receptor, it activates an enzyme, which activates another enzyme, which activates two more enzymes, which finally activate glucose transport, which acts as a gateway for glucose to enter the cell. So, insulin is the key that unlocks the door into our muscle cells.
但是，如果没有胰岛素呢？ 那么，那么血糖就会卡在血液里，撞在通往肌肉的门上，无法进入。 所以，无处可去，血糖水平会不断上升。 What if there was no insulin, though? Well, blood sugar would be stuck out in the bloodstream, banging on the door to our muscles, and not able to get inside. And so, with nowhere to go, sugar levels would rise and rise.
这就是 1 型糖尿病发生的情况；胰腺中制造胰岛素的细胞被破坏，而没有胰岛素时，血液中的糖不能从血液中进入肌肉，血糖升高。 That’s what happens in type 1 diabetes; the cells in the pancreas that make insulin get destroyed, and without insulin, sugar in the blood can’t get out of the blood into the muscles, and blood sugar rises.
但也有第二种方式可以得到高血糖。 如果有足够的胰岛素，但胰岛素不起作用？ But, there’s a second way we could end up with high blood sugar. What if there’s enough insulin, but the insulin doesn’t work?
钥匙在那里，但是有东西粘在锁上面。 这就是所谓的胰岛素抵抗。 The key is there, but something’s gummed up the lock. This is called insulin resistance.
我们的肌肉细胞对胰岛素的作用产生抗性。是什么阻塞了我们肌肉细胞的锁，从而阻止胰岛素让糖进入呢？ Our muscle cells become resistant to the effect of insulin. What’s gumming up the door locks on our muscle cells, preventing insulin from letting sugar in? 脂肪。 所谓的肌内细胞脂质，或肌肉细胞内的脂肪。 Fat. What’s called intramyocellular lipid, or fat inside our muscle cells.
血液中的脂肪会聚集在肌肉细胞内部，形成有毒的脂肪分解产物和自由基，从而阻断信号通路进程。 Fat in the bloodstream can build up inside the muscle cells, create toxic fatty breakdown products and free radicals that can block the signaling pathway process.
所以，无论我们的血液中有多少胰岛素，它都无法打开葡萄糖门，血液中的血糖水平也会增加。 So, no matter how much insulin we have out in our blood, it’s not able to open the glucose gates, and blood sugar levels build up in the blood.
这种脂肪，尤其是饱和脂肪，引起胰岛素抵抗，直到开发出现代的磁共振断层扫描技术（MRI）才知道，当脂肪被注入血液中时，肌肉里发生了什么。 This mechanism, by which fat ( specifically saturated fat ) induces insulin resistance, wasn’t known until fancy MRI techniques were developed to see what was happening inside people’s muscles as fat was infused into their bloodstream.
这就是他们发现提高血脂水平的方式，“通过抑制葡萄糖向肌肉的转运而引起胰岛素抵抗”。 And, that’s how scientists found that elevation of fat levels in the blood “ causes insulin resistance by inhibition of glucose transport ” into the muscles.
而且，这可能会在短短的3小时内发生。 摄取一次高脂饮食就能开始引起胰岛素抵抗，仅在160分钟后就能抑制葡萄糖摄入。 And, this can happen within just three hours. One hit of fat can start causing insulin resistance, inhibiting glucose uptake after just 160 minutes.
青少年也会发生同样的情况。 脂肪流入他们的血液。 它积聚在肌肉中，并降低胰岛素敏感性— 表明血液中脂肪增加可能是胰岛素抵抗的重要因素。 Same thing happens to adolescents. You infuse fat into their bloodstream. It builds up in their muscles, and decreases their insulin sensitivity — showing that increased fat in the blood can be an important contributor to insulin resistance. 然后，你可以做相反的实验。 降低人体血液中的脂肪含量，胰岛素抵抗马上就降低了。 Then, you can do the opposite experiment. Lower the level of fat in people’s blood, and the insulin resistance comes right down.
清除血液中的脂肪，也可以清除血液中的糖。所以，这解释了这一发现。 Clear the fat out of the blood, and you can clear the sugar out of the blood. So, that explains this finding.
在高脂肪饮食中，生酮饮食，胰岛素同样不能很好地工作。 我们的身体是胰岛素抵抗的。 On the high-fat diet, the ketogenic diet, insulin doesn’t work as well. Our bodies are insulin-resistant.
但是，随着我们饮食中的脂肪含量越来越低，胰岛素的效果越来越好。 But, as the amount of fat in our diet gets lower and lower, insulin works better and better.
这清楚地表明，甚至健康个体的糖耐量可以“通过采用低碳水化合物，高脂肪饮食而受损”。 This is a clear demonstration that the sugar tolerance of even healthy individuals can be “ impaired by administering a low-carb, high-fat diet. ”
但我们可以减少胰岛素抵抗，这是糖尿病前期的成因，通过减少饱和脂肪的摄入来减少 2 型糖尿病的病因。 But, we can decrease insulin resistance — the cause of prediabetes, the cause of type 2 diabetes — by decreasing saturated fat intake. （注：视频翻译及字幕制作：老玉米） Michael Greger 医生笔记：这是关于 2 型糖尿病病因的三部分视频系列的第一部分，以便更好地了解饮食干预措施以预防和治疗这种流行病。 This was the first of a three-part video series on the cause of type 2 diabetes, so as to better understand dietary interventions to prevent and treat the epidemic. |
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来自： zhihui2016 > 《健康 饮食》
