誰說不健康不是吃肉惹的禍?

The Myth of High-Protein Diets

誰說不健康不是吃肉惹的禍?

MANY people have been making the case that Americans have grown fat because they eat too much starch and sugar, and not enough meat, fat and eggs. Recently, the Dietary Guidelines Advisory Committee lifted recommendations that consumption of dietary cholesterol should be restricted, citing research that dietary cholesterol does not have a major effect on blood cholesterol levels. The predictable headlines followed: “Back to Eggs and Bacon?”

很多人都說，美國人變得肥胖是因?yàn)樗麄兂粤颂嗟矸酆吞牵鴽]有攝入足夠的肉類、脂肪和雞蛋。近日，美國膳食指南咨詢委員會(huì)(Dietary Guidelines Advisory Committee)取消了“膳食中的膽固醇消耗應(yīng)該受到限制”的建議。它援引的一項(xiàng)研究認(rèn)為，飲食中的膽固醇不會(huì)對(duì)血液中的膽固醇水平產(chǎn)生重大影響。不出所料，一些媒體打出了這樣的大標(biāo)題：“回歸雞蛋和熏肉?”

But, alas, bacon and egg yolks are not health foods.

但是，唉，熏肉和蛋黃都不是健康食品。

Although people have been told for decades to eat less meat and fat, Americans actually consumed 67 percent more added fat, 39 percent more sugar, and 41 percent more meat in 2000 than they had in 1950 and 24.5 percent more calories than they had in 1970, according to the Agriculture Department. Not surprisingly, we are fatter and unhealthier.

雖然這幾十年來，人們都被告知要少吃肉類和脂肪，但與1950年相比，美國人在2000年實(shí)際消耗的添加脂肪增加了67%，糖分增加了39%，肉類增加了41%，而且比1970年多攝入了24.5%的卡路里。因此毫不奇怪，我們變得更胖了，健康水平也下滑了。

The debate is not as simple as low-fat versus low-carb. Research shows that animal protein may significantly increase the risk of premature mortality from all causes, among them cardiovascular disease, cancer and Type 2 diabetes. Heavy consumption of saturated fat and trans fats may double the risk of developing Alzheimer’s disease.

這場辯論不是簡單地比較低脂肪飲食與低碳水化合物飲食。研究表明，動(dòng)物蛋白可能會(huì)大幅增加各種原因?qū)е碌倪^早死亡風(fēng)險(xiǎn)，這些原因包括心血管疾病、癌癥和2型糖尿病。大量攝入飽和脂肪和反式脂肪，可能會(huì)讓阿爾茨海默氏癥的患病風(fēng)險(xiǎn)增加一倍。

A study published last March found a 75 percent increase in premature deaths from all causes, and a 400 percent increase in deaths from cancer and Type 2 diabetes, among heavy consumers of animal protein under the age of 65 — those who got 20 percent or more of their calories from animal protein.

去年3月公布的一項(xiàng)研究發(fā)現(xiàn)，在大量攝入動(dòng)物蛋白的65歲以下人群中，各種原因?qū)е碌倪^早死亡數(shù)量增加了75%，因癌癥和2型糖尿病而死亡的人數(shù)增加了400%。這些人攝入的的卡路里中，超過20%都來自動(dòng)物蛋白。

Low-carb, high-animal-protein diets promote heart disease via mechanisms other than just their effects on cholesterol levels. Arterial blockages may be caused by animal-protein-induced elevations in free fatty acids and insulin levels and decreased production of endothelial progenitor cells (which help keep arteries clean). Egg yolks and red meat appear to significantly increase the risk of coronary heart disease and cancer due to increased production of trimethylamine N-oxide, or TMAO, a metabolite of meat and egg yolks linked to the clogging of arteries. (Egg whites have neither cholesterol nor TMAO.)

低碳水化合物加高動(dòng)物蛋白的飲食促發(fā)心臟疾病，其方式不僅僅是影響膽固醇水平那樣簡單。在動(dòng)物蛋白誘導(dǎo)下，游離脂肪酸和胰島素水平升高，內(nèi)皮祖細(xì)胞(有助于保持動(dòng)脈清潔)的生成減少，從而可能引起動(dòng)脈堵塞。蛋黃和紅肉似乎明顯增加了冠狀動(dòng)脈心臟疾病和癌癥的患病風(fēng)險(xiǎn)，因?yàn)樗鲞M(jìn)了三甲胺氧化物 (TMAO)的生成。TMAO是肉和蛋黃的代謝物，與動(dòng)脈堵塞有關(guān)。(蛋清既沒有膽固醇，也不含TMAO)。

Animal protein increases IGF-1, an insulin-like growth hormone, and chronic inflammation, an underlying factor in many chronic diseases. Also, red meat is high in Neu5Gc, a tumor-forming sugar that is linked to chronic inflammation and an increased risk of cancer. A plant-based diet may prolong life by blocking the mTOR protein, which is linked to aging. When fat calories were carefully controlled, patients lost 67 percent more body fat than when carbohydrates were controlled. An optimal diet for preventing disease is a whole-foods, plant-based diet that is naturally low in animal protein, harmful fats and refined carbohydrates. What that means in practice is little or no red meat; mostly vegetables, fruits, whole grains, legumes and soy products in their natural forms; very few simple and refined carbohydrates such as sugar and white flour; and sufficient “good fats” such as fish oil or flax oil, seeds and nuts. A healthful diet should be low in “bad fats,” meaning trans fats, saturated fats and hydrogenated fats. Finally, we need more quality and less quantity.

動(dòng)物蛋白增加了胰島素樣生長激素IGF-1和慢性炎癥，后者是很多慢性疾病的潛在成因。另外，紅肉含有很高的Neu5Gc，這是一種導(dǎo)致腫瘤的糖分，可能會(huì)引起慢性炎癥，增加患癌風(fēng)險(xiǎn)。以植物為主的飲食則可以延年益壽，因?yàn)樗梢宰钄嘁鹚ダ系膍TOR蛋白質(zhì)。與控制碳水化合物時(shí)相比，當(dāng)脂肪熱量受到嚴(yán)格控制時(shí)，患者減去了67%的額外身體脂肪。預(yù)防疾病的最佳飲食，是基于植物的全面膳食，其中動(dòng)物蛋白、對(duì)人體有害脂肪，以及精制的碳水化合物含量天然就比較低。這意味著在日常生活中少吃或不吃紅肉;主要吃未經(jīng)深加工的蔬菜、水果、全谷類，豆類和豆制品;像糖和白面粉這種單純和精制碳水化合物，只消耗極少量;要攝入足夠的“好脂肪”，比如魚油或亞麻籽油，種子和堅(jiān)果。少吃“壞脂肪”，即反式脂肪、飽和脂肪和氫化脂肪。最后，我們還需要提高質(zhì)量，減少數(shù)量。

My colleagues and I at the nonprofit Preventive Medicine Research Institute and the University of California, San Francisco, have conducted clinical research proving the many benefits of a whole-foods, plant-based diet on reversing chronic diseases, not just on reducing risk factors such as cholesterol. Our interventions also included stress management techniques, moderate exercise like walking and social support.

我和非營利機(jī)構(gòu)預(yù)防醫(yī)學(xué)研究院(Preventive Medicine Research Institute)及加州大學(xué)舊金山分校(University of California, San Francisco)的同事們進(jìn)行過臨床研究，證明基于植物的全面膳食在逆轉(zhuǎn)慢性疾病方面有著眾多好處，而不只是降低膽固醇等風(fēng)險(xiǎn)因素。我們的干預(yù)措施還包括壓力管理技巧、散步這樣的適度運(yùn)動(dòng)，以及社交支持。

We showed in randomized, controlled trials that these diet and lifestyle changes can reverse the progression of even severe coronary heart disease. Episodes of chest pain decreased by 91 percent after only a few weeks. After five years there were 2.5 times fewer cardiac events. Blood flow to the heart improved by over 300 percent.

我們的隨機(jī)對(duì)照試驗(yàn)研究顯示，在改變飲食習(xí)慣和生活方式之后，就連嚴(yán)重的冠狀動(dòng)脈心臟疾病發(fā)展都可以逆轉(zhuǎn)。僅僅幾周后，患者胸痛發(fā)作次數(shù)就減少了91%。五年之后，心臟事件減少了2.5倍。流向心臟的血液改善了300%。

Other physicians, including Dr. Kim A. Williams, the president of the American College of Cardiology, are also finding that these diet and lifestyle changes can reduce the need for a lifetime of medications and transform people’s lives. These changes may also slow, stop or even reverse the progression of early-stage prostate cancer, judging from results in a randomized controlled trial.

美國心臟病學(xué)會(huì)(American College of Cardiology)會(huì)長金·A·威廉斯(Kim A. Williams)博士等其他醫(yī)生還發(fā)現(xiàn)，改變飲食習(xí)慣和生活方式可以減少終生用藥的需要，可以讓人們的生活煥然一新。從隨機(jī)對(duì)照試驗(yàn)的結(jié)果來看，這些改變還有可能減緩、中止甚至逆轉(zhuǎn)早期前列腺癌癥的發(fā)展。

These changes may also alter your genes, turning on genes that keep you healthy, and turning off genes that promote disease. They may even lengthen telomeres, the ends of our chromosomes that control aging.

這些改變也可能會(huì)轉(zhuǎn)變你的基因，啟動(dòng)讓你健康的基因，關(guān)閉促發(fā)疾病的基因。它們甚至可能延長端粒;它是染色體的末端，作用是控制衰老。

The more people adhered to these recommendations (including reducing the amount of fat and cholesterol they consumed), the more improvement we measured — at any age. But for reversing disease, a whole-foods, plant-based diet seems to be necessary.

無論屬于哪個(gè)年齡階段，人們越是遵循這些建議(包括減少脂肪和膽固醇攝入)，我們測量到的改善也就越大。但對(duì)于逆轉(zhuǎn)疾病而言，基于植物的全面膳食似乎是必不可少。