反式脂肪才是心臟病的真兇

1、反式脂肪才是心臟病的真兇噴香的豬油、奶油能不能吃？豆油菜、籽油、調(diào)和 油能不能吃？美國(guó)科學(xué)家?guī)炷_教授 (Fred Kummerow )答 案是，只要不是反式脂肪( trans fat )都可以吃。但必須避 免高溫煎炸導(dǎo)致的植物油氧化危害。原因很簡(jiǎn)單天然油脂會(huì) 很快在體內(nèi)降解。反式脂肪( trans fat )熬得住歲月，“頑強(qiáng) 地”在我們的心血管內(nèi)存留。 堆積在心臟上， 最終將人們殺死。 所以建議仔細(xì)閱讀一下手里食品的營(yíng)養(yǎng)標(biāo)簽，看看是否含有 反式脂肪及比例。它將決定你的明天。1957 年，初出茅廬的庫(kù)默羅醫(yī)生請(qǐng)求當(dāng)?shù)匾患裔t(yī)院給 他一些心臟病人的血管樣本做研究。不出意料，他發(fā)現(xiàn)這些 心臟病人的

2、血管充滿(mǎn)了脂肪堆積，但這不是一般的脂肪，而 是一種特別的脂肪，也就是我們今天所熟知的反式脂肪 ( trans fat )。庫(kù)默羅醫(yī)生因此深入研究，得出結(jié)論，證明了反式脂肪 和心臟病的直接關(guān)聯(lián)。但是，他的研究結(jié)論并沒(méi)有得到廣泛 接受這過(guò)程經(jīng)歷了 30 年。而直到 50 年后，美國(guó)的 FDA 才正式?jīng)Q定在食物中去除反式脂肪。真相總是難以接受的。庫(kù)默羅醫(yī)生今年 99 歲，至今仍然繼續(xù)為伊利諾亞大學(xué) 工作。過(guò)去兩年，他連續(xù)發(fā)表了幾篇研究，矛頭直指造成今 天廣泛的心臟病的元兇： 多鏈不飽和脂肪酸的植物油， 例如， 大豆油，玉米油，和葵花子油。庫(kù)默羅醫(yī)生指出，問(wèn)題不在于膽固醇，甚至不在于壞膽固醇（LDL

3、）,膽固醇和心臟病毫無(wú)關(guān)系。 問(wèn)題只在于膽固醇 的被氧化。而那些高溫油炸的烹飪過(guò)程是最容易把植物油氧 化的。庫(kù)默羅醫(yī)生的研究很好的解釋了為什么半數(shù)的心臟病 病人他們的體內(nèi)的膽固醇是正常的，甚至是低的。庫(kù)默羅醫(yī)生自己的飲食也證明了這點(diǎn)，除了吃新鮮的蔬 菜水果外，他還每周吃幾次紅肉，飲用全脂牛奶。他已經(jīng)不記得最后一次吃油炸的東西是什么時(shí)候了，也 從未吃過(guò)人造奶油，但是他會(huì)用黃油（ Butter ）來(lái)炒蛋。庫(kù)默羅醫(yī)生說(shuō)，雞蛋是大自然賜給人類(lèi)的最好的食物， 包含了所有的 9 種氨基酸，還有多種維他命和礦物質(zhì)。吃雞 蛋只吃蛋白不吃蛋黃真的是瘋了。庫(kù)默羅醫(yī)生的研究因?yàn)樘^(guò)超前，所以他早期曾受到很 大困難，

4、甚至連研究經(jīng)費(fèi)都很難拿到。科學(xué)界一直都認(rèn)為如 豬油牛油之類(lèi)的飽和脂肪才是心臟病的元兇。所幸歷史是人民寫(xiě)的。科學(xué)家們總是會(huì)出錯(cuò)的。傳統(tǒng)總 是正確的。雖然今年已經(jīng) 99 歲，但是庫(kù)默羅醫(yī)生的飽和脂肪飲食（黃油豬油）令他仍然擁有完美的如同百科全書(shū)般的記憶 力。他仍然清楚記得所有的人，時(shí)間，地點(diǎn)，更令人驚嘆的 是，是那些復(fù)雜的科學(xué)概念。背景：人工反式脂肪是指通過(guò)氫化處理，把液態(tài)植物油 轉(zhuǎn)為固態(tài)或半固體的氫化油。其優(yōu)點(diǎn)是改善味道、耐高溫、 不易變質(zhì)、保存期長(zhǎng)，而且比飽和動(dòng)物脂肪便宜。以前人們 一度以為氫化油較動(dòng)物脂肪健康，但研究證明，吸取氫化油 會(huì)增加壞膽固醇， 同時(shí)減少好膽固醇， 增加患心臟病的風(fēng)險(xiǎn)。

5、 美國(guó)食品及藥物管理局相信一旦禁用人工反式脂肪后，每年 可減少兩萬(wàn)宗心臟病病發(fā)個(gè)案，也會(huì)減少七千人死亡。反式脂肪酸常添加在哪類(lèi)食品中？日常生活中，含有反式脂肪酸的食品很多，諸如蛋糕、 糕點(diǎn)、餅干、面包、沙拉醬、薯片、爆米花、巧克力、冰淇 淋凡是松軟香甜，口味獨(dú)特的含油（植物奶油、人造黃油 等）食品， 都含有反式脂肪酸。 原因是， 用植物油催化加氫制 取脂肪時(shí)，反式脂肪酸也同時(shí)生成了。一般來(lái)說(shuō)，口感很香、脆、滑的多油食物就可能使用了 部分氫化植物油，富含氫化植物油的食品就可能有反式脂肪 酸。還有速食店和西式快餐店的食物也常常使用氫化油脂。 現(xiàn)制現(xiàn)售的奶茶尤其要注意， 因?yàn)樗叭榛薄盎瑵?rùn)”的狀態(tài)

6、特性 需要?dú)浠参镉?。氫化植物油就是反式脂肪酸嗎？植物油不完全氫化才?huì)產(chǎn)生反式脂肪，完全氫化的部分就不是反式脂肪而是飽和脂肪，因此氫化植物油不能等同于 反式脂肪。比如某些產(chǎn)品的加工需要完全氫化的植物油，因 此這類(lèi)食品中反式脂肪酸的含量其實(shí)很低，當(dāng)然完全氫化會(huì) 使飽和脂肪含量大幅上升，也不宜過(guò)多食用。附件 1 ： against-trans-fat.html?_r=0HealthA Lifelong Fight Against Trans FatsBy MELANIE WARNERDEC. 16, 2013PhotoFred Kummerow, 99, in his lab at the Uni

7、versity of Illinois where he still directs research. Credit Sally Ryan for The New York TimesIn 1957, a fledgling nutrition scientist at the University of Illinois persuaded a hospital to give him samples of arteries from patients who had died of heart attacks.When he analyzed them, he made a startl

8、ing discovery. Not surprisingly, the diseased arteries were filled with fat but it was a specific kind of fat. The artificial fatty acids called trans fats, which come from the hydrogen-treated oils used in processed foods like margarine, had crowded out other types of fatty acids.The scientist, Fre

9、d Kummerow, followed up with a study that found troubling amounts of artery-clogging plaque in pigs given a diet heavy in artificial fats. He became a pioneer of trans-fat research, one of the first scientists to assert a link between heart disease and processed foods.It would be more than three dec

10、ades before those findings were widely accepted and five decades before the Food and Drug Administration decided that trans fats should be eliminated from the food supply, as it proposed in a rule issued last month.PhotoFred Kummerow in 1953.Now, Dr. Kummerow (KOO-mer-ow) is still active at age 99,

11、living a few blocks from the university, where he runs a small laboratory. And he continues to come to contrarian conclusions about fat and heart disease.In the past two years, he has published four papers in peer-reviewed scientific journals, two of them devoted to another major culprit he has sing

12、led out as responsible for atherosclerosis, or the hardening of the arteries: an excess of polyunsaturated vegetable oils like soybean, corn and sunflower exactly the types of fats Americans have been urged to consume for the past several decades.The problem, he says, is not LDL, the“ bad cholestero

13、lwidely considered to be the major cause of heart disease. What matters is whether the cholesterol and fat residing in those LDL particles have been oxidized. (Technically, LDL is not cholesterol, but particles containing cholesterol, along with fatty acids and protein.)“ Cholesterol has nothing to

14、do with heart disease, except if it s oxidized, ” Dr. Kummerow said. Oxidation is achemical process that happens widely in the body, contributing to aging and the development of degenerative and chronic diseases. Dr. Kummerow contends that the high temperatures used in commercial frying cause inhere

15、ntly unstable polyunsaturated oils to oxidize, and that these oxidized fatty acids become a destructive part ofLDL particles. Even when not oxidized by frying, soybean and corn oils can oxidize inside the body.If true, the hypothesis might explain why studies have found that half of all heart diseas

16、e patients have normal or low levels of LDL.“ You can have fine levels of LDL and still be in trouble if a lot of that LDL is oxidized,” Dr. Kummerow said.This leads him to a controversial conclusion: that the saturated fat in butter, cheese and meats does not contribute to the clogging of arteries

17、and in fact isbeneficial in moderate amounts in the context of a healthy diet (lots of fruits, vegetables, whole grains and other fresh, unprocessed foods).Continue reading the main storyHis own diet attests to that. Along with fruits, vegetables and whole grains, he eats red meat several times a we

18、ek and drinks whole milk daily.He cannot remember the last time he ate anything deep-fried. He has never used margarine, and instead scrambles eggs in butter every morning. He calls eggs one of nature s most perfect foods, something he has been preaching since the 1970s, when the consumption ofchole

19、sterol-laden eggs was thought to be a one-way ticket to heart disease.he said.“Eggs have all of the nine amino acids you need to build cells, plus important vitamins and minerals, “It s crazy to just eat egg whites. Not a good practice at all.Dr. Robert H. Eckel, an endocrinologist and former presid

20、ent of the American Heart Association, agreed that oxidized LDL was far worse than nonoxidized LDL in terms of creating plaque.But he disputed Dr. Kummerows contention thatsaturated fats are benign and that polyunsaturated vegetable oils promote hea rt disease.“ There are studiesthat clearly show a

21、substitution of saturated fats with polyunsaturated fats leads to a reduction in cardiovascular disease, ” said Dr. Eckel, a professor at the University of Colorado.Robert L. Collette, the president of the Institute of Shortening and Edible Oils, a trade association, says oil manufacturers work with

22、 their customers to take precautions against oxidation.“ Oxidation is something that consumers can detect,he said.Therefore, it is in everyoneeresstbteost intcontrol it.The long arc of Fred Kummerows life and careerillustrates the frustratingly slow pace of science and the ways in which scientific c

23、onformity can hinder the search for answers. Born in Germany just after World War I broke out, he moved to Milwaukee with his family when he was 9. His father, who worked at a cement block factory, did not have the money to send him to college, so Dr. Kummerow worked full time at a drug distribution

24、 company while attending the University of Wisconsin in the evenings. After he earned a Ph.D. in biochemistry, his first job was at Clemson University in South Carolina, where he helped prevent thousands of deaths in the South from pellagra, a disease resulting from a deficiency of vitamin B3.His ea

25、rly rese arch on trans fats was “ resoundingly criticized and dismissed, ” said Dr. Walter Willett, the chairman of the nutrition department at the Harvard School of Public Health, who credited Dr. Kummerow with prompting his desire to include trans fats in the NursesHealth Study. A 1993 finding fro

26、m that study, which showed a direct link between the consumption of foods containing trans fats and heart disease in women, was a turning point in scientific and medical thinking about trans fats.“ He had great difficulty getting funding because the heart disease prevention world strongly resisted t

27、he idea that trans fats were the problem,” Dr. Willett continued.their view, saturated fats were the big culprit in heart disease. Anything else w as a distraction from that.”At an age when life itself is an accomplishment, Dr. Kummerow said he had no intention of stepping away from the work that ha

28、s consumed him for six decades. He continues to work from home and talks daily to the two scientists who work in his lab, which receives funding from the Weston A. Price Foundation.His wife of 70 years, Amy, died last year at age 94 from Parkinson s disease; he has three children, three grandchildre

29、n and a great-grandchild.He takes no medications, and his mind shows no sign of aging: He has an encyclopedic recall for names, dates and, more impressive, complex scientific concepts. After his muscles became inflamed from a blood pressure drug that he has since stopped taking, he started using a w

30、heelchair combined with a walker.His most significant health problem, appropriately enough, was an artery blockage at age 89 probably aresult of the inevitable effects of aging, not diet.Bypass surgery took care of the blockage, and the fact that he now has an artery from his arm running into his he

31、art has made him even more determined to keep working. Heart disease remains the leading cause of death for Americans, and he would like to stick around to continue funding research that will help change that.“ What I really want is to see trans fats gone finally, said, “ and for people to eat bette

32、r and have a more accurate understanding of what really causes heart disease. ”A version of this article appears in print on December 17, 2013, on page D2 of the New York edition with the headline: A Lifelong Fight Against Trans Fats.附件 2 ：FDA 發(fā)布的新聞/NewsEvents/Newsroom/PressAnnounc

33、ements/ucm373939.htmFDA NEWS RELEASEFor Immediate Release:?Nov. 7, 2013?Media Inquiries:?ShellyBurgess,?, 301-796-4651Consumer Inquiries:?1-888-INFO-FDFDA takes step to further reduce?trans?fats in processed foodsReducing trans fat intake could prevent thousands of heart att

34、acks and deaths?The U.S. Food and Drug Administration announced its preliminary determination that?partially hydrogenated oils (PHOs), the primary dietary source of artificial?trans?fat in processed foods, are not“ generally recognized as safe” foruse in food. The FDA s preliminary determaintion is

35、basedon available scientific evidence and the findings of expert scientific panels.?The agency has opened a 60-day comment period on this preliminary determination to collect additional data and to gain input on the time potentially needed for food manufacturers to reformulate products that currentl

36、y contain artificial?trans?fat should this determination befinalized.“ While consumption of potentially harmful artificial?trans?fat has declined over the last two decades in the United States, current intake remains a significant public health concern, ” said FDA Commissioner Margaret A. Hamburg, M

37、.D.“ The FDA s action today is an importantstep toward protecting more Americans from the potential dangers of?trans?fat. Further reduction in the amount of?trans?fat in the American diet could prevent an additional 20,000 heart attacks and 7,000 deaths fromheart disease each year a critical step in

38、 the protection of Americans health. ”Consumption of?trans?fat raises low-density lipoprotein (L DL), or“bad” cholesterol, increasing the riskof coronary heart disease. The independent Institute of Medicine (IOM)?has concluded that?trans?fat provides no known health benefit and that there is no safe

39、 level of consumption of artificial?trans?fat. Additionally, the IOM recommends that consumption of?trans?fat should be as low as possible while consuming a nutritionally adequate diet.In recent years, many food manufacturers and retailers have voluntarily decreased?trans?fat levels in many foods an

40、d products they sell.?Trans?fat can be found in some processed foods, such as certain desserts, microwave popcorn products, frozen pizzas, margarines and coffee creamers.?Numerous retailers and manufacturers have already demonstrated that many of these products can be made without?trans?fat. ?Thanks

41、 to these efforts, along with public education, the consumption of?trans?fat in American diets has been significantly reduced. Since?trans?fat content information began appearing in the Nutrition Facts label of foods in 2006,?trans?fat intake among American consumers has declined from 4.6 grams per

42、day in 2003 to about 1 gram per day in 2012.“ One of the FDA s core regulatory functions is ensuring that food, including all substances added to food, is safe, ” said Michael Taylor, the FDA s deputycommissioner for foods and veterinary medicine.“ Foodmanufacturers have voluntarily decreased?trans?

43、fat levels in many foods in recent years, but a substantial number ofproducts still contain partially hydrogenated oils, which are the major source of?trans?fat in processed food. ”Following?a review of the submitted comments, if the?FDA finalizes its preliminary determination, PHOs would be conside

44、red“ food additives” and could not beused in food unless authorized by regulation. If such a?determination were made, the agency would provide adequate time for producers to reformulate products in order to minimize market disruption.?The FDA spreliminary determination is only with regard to PHOs an

45、d does not affect?trans?fat that naturally occurs in small amounts in certain meat and dairy products.More information about?trans?fat and information the FDA is seeking is available through a Federal Register?notice. Thedocket?will be open for comment for 60 days.To submit comments by mail, send to

46、 the FDA at:Division of Dockets Management (HFA-305)Food and Drug Administration 5630 Fishers Lane, Rm. 1061Rockville, MD 20852All submissions must include the agency name and docket number.For more information:* Federal Register Notice:?Tentative Determination of Food Additive Status of Partially H

47、ydrogenated Oils:?Request for Comments and Scientific Data and Information?* National Academies of Science, Institute of Medicine Report:?Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids?* HHS Million Hearts Initiative* USDA Dietary G

48、uidelines for Americans, 2010?* FDA Consumer Update: FDA Targets?Trans?Fat in Processed Foods* FDA Voice:?Trans?Fat: Taking the Next Important Step?* Talking about?Trans?Fat-What You Need to KnowThe FDA, an agency within the U.S. Department of Health and Human Services, protects the public health by

49、 assuring the safety, effectiveness, and security of human and veterinary drugs, vaccines and other biological products for human use, and medical devices. The agency also is responsible for the safety and security of our nation s food supply, cosmetics, dietary supplements, products that give off electronic radiation, and for regulating tobacco products.附件 3 ：伊利諾大學(xué)發(fā)布新聞 /lb/article/5510/79081 Professor Fred Kummerow, 99, led the effort to ban trans fats11/7/2013The U.S. Food and Drug Administration has announced that it will take on the thorny