Greger （格雷格）醫生筆記：
這是三個系列視頻的第三部分，從「什麼原因導致胰島素抵抗？」開始，然後是「溢出效應將肥胖症與糖尿病聯繫起來」。 我希望我可以將它們全部整合到一個視頻中，但這會太長。
This is the third of a three-part series, starting with What Causes Insulin Resistance? and The Spillover Effect Links Obesity to Diabetes. I wish I could have fit it all into one video, but it would have just been too long.
糖尿病系列視頻之一：動畫演示」胰島素抵抗」是如何發生的。
糖尿病系列視頻之二：肥胖症與糖尿病有啥關係？溢出效應又是怎麼一回事？
本視頻由Michael Greger醫生於2015年2月9日發布，來自NutritionFacts.org — 能救命的營養學。
如何從各種相互矛盾的有關營養與疾病的信息中找到靠譜的信息？
Michael Greger 醫生是暢銷書《How Not to Die》一書作者，中文譯本：繁體版書名為《食療聖經》。簡體版書名為《救命》，將於今年5月底出版。
「脂毒性：飽和脂肪如何升高血糖」
Lipotoxicity: How Saturated Fat Raises Blood Sugar
摘要：採取植物性飲食的人的肌肉細胞脂肪堆積較少，且胰島素抵抗較少的原因可能是因為飽和脂肪似乎最能削弱血糖控制。
The reason those eating plant-based diets have less fat buildup in their muscle cells and less insulin resistance may be because saturated fats appear to impair blood sugar control the most.
脂肪和胰島素抵抗之間的關聯現在被廣泛接受 — 所謂的異位脂肪堆積 — 脂肪堆積在它不應該存在的地方，比如在我們的肌肉細胞內。
The association between fat and insulin resistance is now widely accepted – so-called ectopic fat accumulation – the accumulation of fat in places it’s not supposed to be, like within our muscle cells.
但並非所有的脂肪都會同等地影響肌肉。
But not all fats affect muscles the same.
脂肪的類型 —飽和或不飽和 — 是至關重要的。
The type of fat – saturated or unsaturated – is critical.
飽和脂肪酸，如棕櫚酸，主要存在於肉類，乳製品和雞蛋中，引起胰島素抵抗，但油酸主要存在于堅果，橄欖和牛油果中，可能實際上改善了胰島素敏感性。
Saturated fats like palmitate, found mostly in meat, dairy, and eggs, cause insulin resistance, but oleate, found mostly in nuts, olives, and avocados may actually improve insulin sensitivity.
什麼原因造成飽和脂肪不好呢？
What makes saturated fat bad?
飽和脂肪會導致更多的這些有毒降解產物和線粒體功能障礙，並增加氧化應激，自由基和炎症，從而造成一個惡性循環，其中飽和脂肪誘導的自由基引起肌肉細胞內的小型發電廠障礙，這導致自由基產生的增加和胰島素信號傳導的損害。
Saturated fat causes more of those toxic breakdown products and mitochondrial dysfunction, and increases oxidative stress, free radicals, and inflammation, establishing a vicious cycle of events in which saturated fat-induced free radicals cause dysfunction in the little power plants within our muscle cells, which causes an increase in free radical production and the impairment of insulin signaling.
充滿飽和脂肪的脂肪細胞在很大程度上激活炎症反應。
Fat cells filled with saturated fat activate an inflammatory response to a far greater extent.
這種增加的炎症，伴隨進食更多的飽和脂肪，已證明可通過自由基和神經醯胺的生成來提高胰島素抵抗。
This increased inflammation, along with eating more saturated fat, has been demonstrated to raise insulin resistance through free radical and ceramide production.
飽和脂肪也被證明對骨骼肌胰島素抵抗有直接作用。
Saturated fat has also been shown to have a direct effect on skeletal muscle insulin resistance.
飽和脂肪的積累增加了肌肉中甘油二酯的含量，這已被證明對肌肉胰島素抵抗有很強的作用。無論血液中的脂肪是來自我們自己的脂肪還是來自動物的脂肪，結果都一樣。
Accumulation of saturated fat increases the amount of diacylglycerol in the muscles, which has been demonstrated to have a potent effect on muscle insulin resistance. It doesn’t matter if the fat in our blood comes from our own fat, or from their fat.
您可以從人身上進行肌肉活組織檢查，並將肌肉中飽和脂肪堆積與胰島素抵抗相關聯。
You can take muscle biopsies from people and correlate the saturated fat buildup in their muscles with insulin resistance.
雖然單不飽和脂肪更有可能被解毒或安全儲存，但飽和脂肪會產生這些有毒的分解產物，如神經醯胺，會導致脂毒性。
While monounsaturated fats are more likely to be detoxified or safely stored away, saturated fats create these toxic breakdown products, like ceramide, that cause lipotoxicity.
Lipo - 意為脂肪，「liposuction」(吸脂)裡的「lipo」(脂)字，以及「toxicity」(毒性)。（譯註：這句話是解釋英文「lipotoxicity」脂毒性這個詞的構成。）肌肉中的這種脂肪毒性是解釋引發胰島素抵抗的眾所周知的概念。
Lipo- meaning fat, as in liposuction, and toxicity. This fat toxicity in our muscles is a well-known concept in the explanation of the trigger for insulin resistance.
我已經談到了飽和脂肪和反式脂肪對其他疾病的發展有促進作用，例如：自身免疫性疾病，癌症和心臟病等，但它們也會引起胰島素抵抗，這是糖尿病前期和2型糖尿病的根本原因。
I』ve talked about the role saturated and trans fats contribute to the progression of other diseases, like autoimmune diseases, cancer, and heart disease, but they can also cause insulin resistance, the underlying cause of prediabetes and type 2 diabetes.
在人類飲食中，飽和脂肪來自動物，而反式脂肪來源於肉類和牛奶，此外還有部分氫化和精煉植物油。
In the human diet, saturated fats are derived from animal sources while trans fats originate in meat and milk, in addition to partially hydrogenated and refined vegetable oils.
這就是為什麼通過實驗將人們從動物脂肪轉移到植物脂肪可以改善胰島素敏感性。
That’s why experimentally shifting people from animal fats to plant fats can improve insulin sensitivity.
胰島素的敏感性被添加乳脂的飲食削弱， 但飲食中添加橄欖中的脂肪，胰島素敏感性不會被削弱。
Insulin sensitivity was impaired on the diet with added butterfat, but not on the diet with added olive fat.
我們知道肌肉長時間暴露於高水平的脂肪導致嚴重的胰島素抵抗，飽和脂肪被證明是最差的。
We know prolonged exposure of our muscles to high levels of fat leads to severe insulin resistance, with saturated fats demonstrated to be the worst.
而且飽和脂肪不僅會導致抑制胰島素信號傳導、激活炎症途徑以及增加自由基。
But they don’t just lead to inhibition of insulin signaling, the activation of inflammatory pathways, and the increase in free radicals.
飽和脂肪還引起基因表達的改變，導致關鍵線粒體酶的抑制，例如肉鹼棕櫚醯轉移酶— 這最終解決了此疑惑，即為什麼素食者具有高60％的脂肪燃燒酶。 他們吃的飽和脂肪較少。
They cause an alteration in gene expression, leading to a suppression of key mitochondrial enzymes, like carnitine palmitoyltransferase – which finally solves the mystery of why those eating vegetarian have a 60% higher expression of that fat-burning enzyme. They’re eating less saturated fat.
那麼那些以植物性飲食為基礎的人有較少的脂肪堵塞肌肉，胰島素抵抗也更少嗎？
So do those eating plant-based diets have less fat clogging their muscles and less insulin resistance too?
之前還沒有關於那些吃純素或素食者的胰島素敏感性或肌肉內細胞脂肪的數據，直到這個研究出現。
There hasn’t been any data available regarding the insulin sensitivity or inside-muscle cell-fat of those eating vegan or vegetarian, until now.
倫敦帝國理工學院的研究人員比較了素食者與雜食者的胰島素抵抗和肌肉脂肪。
Researchers at the Imperial College of London compared the insulin resistance and muscle fat of vegans versus omnivores.
那些吃植物性飲食的人具有非常苗條的不公平優勢，因此他們找到與純素者一樣瘦的雜食者，以查看植物性飲食是否具有直接益處，為了與通過幫助人們減肥而從肌肉中間接去除脂肪進行比較。
Now those eating plant-based diets have the unfair advantage of being so much slimmer, so they found omnivores who were as skinny as vegans to see if plant-based diets had a direct benefit, as opposed to indirectly pulling fat out of the muscles by helping people lose weight in general.
他們發現純素者肌肉細胞中的脂肪少得多，與體重相同的雜食者相比。
They found significantly less fat trapped in the muscle cells of vegans compared to omnivores even at the same body weight.
他們發現純素者有更好的胰島素敏感性，更好的血糖和更好的胰島素水平，並且令人興奮是顯著改善了β細胞功能— 胰腺中首先製造胰島素的細胞。
They found better insulin sensitivity, better blood sugar levels, better insulin levels, and, excitingly, significantly improved beta-cell function – the cells in the pancreas that make insulin in the first place.
他們得出結論， 吃純素不僅預期具有心臟保護作用，有助於預防我們的＃1殺手 —心臟病 —並且素食主義也可能對β細胞有保護作用，也有助於預防我們的第七大死因— 糖尿病。
They conclude that eating vegan is not only expected to be cardioprotective, helping prevent our #1 killer – heart disease – but that veganism may be beta cell protective as well, helping also to prevent our seventh leading cause of death – diabetes.
參考文獻：
L M Sparks. H Xie, R A Koza, R Mynatt, M W Hulver, G A Bray, S R Smith. A high-fat diet coordinately downregulates genes required for mitochondrial oxidative phosphorylation in skeletal muscle. Diabetes. 2005 Jul;54(7):1926-33.
W J Evans. Oxygen-carrying proteins in meat and risk of diabetes mellitus. JAMA Intern Med. 2013 Jul 22;173(14):1335-6.
D Estadella, C M da Penha Oller do Nascimento, L M Oyama, E B Ribeiro, A R Damaso, A de Piano. Lipotoxicity: effects of dietary saturated and transfatty acids. Mediators Inflamm. 2013; Epub 2013 Jan 31.
L M Goff, J D Bell, P W So, A Dornhorst, G S Frost. Veganism and its relationship with insulin resistance and intramyocellular lipid. Eur J Clin Nutr. 2005 Feb;59(2):291-8.
G Perseghin, P Scifo, F De Cobelli, E Pagliato, A Battezzati, C Arcelloni, A Vanzulli, G Testolin, G Pozza, A Del Maschio, L Luzi. Intramyocellular triglyceride content is a determinant of in vivo insulin resistance in humans: a 1H-13C nuclear magnetic resonance spectroscopy assessment in offspring of type 2 diabetic parents. Diabetes. 1999 Aug;48(8):1600-6.
B Vessby, M Uusitupa, K Hermansen, G Riccardi, AA Rivellese, L C Tapsell, C Nalsen, L Berglund, A Louheranta, B M Rasmussen, G D Calvert, A Maffetone, E Pedersen, I B Gustafsson, L H Storlien, KANWU Study. Substituting dietary saturated for monounsaturated fat impairs insulin sensitivity in healthy men and women: The KANWU Study. Diabetologia. 2001 Mar;44(3):312-9.
J Gojda, J Patkova, M Jacek, J Potockova, J Trnka, P Kraml, M Andel. Higher insulin sensitivity in vegans is not associated with higher mitochondrial density. Eur J Clin Nutr. 2013 Dec;67(12):1310-5.
C J Nolan, C Z Larter. Lipotoxicity: why do saturated fatty acids cause and monounsaturates protect against it? J Gastroenterol Hepatol. 2009 May;24(5):703-6.
J Ye. Role of insulin in the pathogenesis of free fatty acid-induced insulin resistance in skeletal muscle. Endocr Metab Immune Disord Drug Targets. 2007 Mar;7(1):65-74.
E W Kraegen, G J Cooney. Free fatty acids and skeletal muscle insulin resistance. Curr Opin Lipidol. 2008 Jun;19(3):235-41.
V T Samuel, G I Shulman. Mechanisms for insulin resistance: common threads and missing links. Cell. 2012 Mar 2;148(5):852-71.
A R Martins, R T Nachbar, R Gorjao, M A Vinolo, W T Festuccia, R H Lambertucci, M F Cury-Boaventura, L R Silveira, R Curi, S M Hirabara. Mechanisms underlying skeletal muscle insulin resistance induced by fatty acids: importance of the mitochondrial function. Lipids Health Dis. 2012 Feb 23;11:30.
H Karlic, D Schuster, F Varga, G Klindert, A Lapin, A Haslberger, M Handschur. Vegetarian diet affects genes of oxidative metabolism and collagen synthesis. Ann Nutr Metab. 2008;53(1):29-32.
編譯者後記：您三個視頻都看完了嗎？現在清楚什麼樣的食物對身體有傷害了嗎？Greger （格雷格）醫生還製作了更多關於糖尿病的視頻:
如何避免由糖尿病前期轉為糖尿病？
用食物逆轉糖尿病
糖尿病視網膜病變可以逆轉嗎？
雞蛋 & 糖尿病
魚 & 糖尿病
等等，Greger 醫生製作的小視頻涵蓋營養與疾病的方方面面，您對哪方面感興趣？歡迎加入「蔬食益生微信交流群」。
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德國美女大學生 麗薩 用中文特別推薦符合 「低脂全蔬食」 原則的健康食譜公眾號：
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關於編譯者：老玉米是美國康奈爾大學坎貝爾營養研究中心《蔬食營養》證書持有者。老玉米的先生是美國內科醫生(MD)，也是位「蔬食醫生」(Plantrician)。
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