Fat, once a dirty word when it came to diet, has been edging back toward respectability. New results from a huge international study help continue to reshape its image while at the same time casting doubt on the wisdom of eating lots of carbohydrates and questioning the “more is better” recommendations for eating fruits and vegetables.
脂肪，在餐桌前曾一度遭人垂弃，如今，它的声名却越发显著，倍受人们关注。一项国际巨型研究得出的多个结果，都在不断重塑脂肪在人们心目中的“形象”。与此同时，研究也对人们食用大量碳水化合物，和摄入“越多越好”的蔬果的观点与建议产生质疑。
The latest evidence comes from data released Tuesday by the international Prospective Urban Rural Epidemiology (PURE) study. Its research team recorded the eating habits of 135,000 adults in 18 countries — including high-income, medium-income, and low-income nations — and followed the participants’ health for more than seven years on average.
最新的证据来自于国际城市流行病学（PURE）于周二公布的研究数据。该研究小组记录了18个国家共135000名成年人的饮食习惯，当中包括高收入、中等收入及低收入国家的饮食习惯，并对参与者的健康状况进行了平均七年以上的调查。
Among the PURE participants, those with the highest intake of dietary fat (35 percent of daily calories) were 23 percent less likely to have died during the study period than those with the lowest fat intake (10 percent of calories). The rates of various cardiovascular diseases were essentially the same across fat intake, while strokes were less common among those with a high fat intake.
在所有PURE受试者中，那些摄入膳食脂肪量（每日35%卡路里）最高的人员在研究期间死亡的几率，要比那些脂肪摄入量（10%卡路里）最低的人低23%。各类心血管疾病的发病率在不同的脂肪摄入量之间基本相同，而在高脂肪摄入量人群中，中风的发病率也相对较低。
Upending conventional wisdom, the findings for carbohydrate intake went in the opposite direction. PURE participants with the highest carbohydrate intake (77 percent of daily calories) were 28 percent more likely to have died than those with the lowest carbohydrate intake (46 percent of calories). The results were presented at the European Society of Cardiology meeting in Barcelona, and published in the Lancet.
而这一项关于碳水化合物摄入量的调查结果，颠覆了大众的传统认识。理论上讲，碳水化合物摄入量最高的PURE受试者（77%每日卡路里）比那些碳水化合物摄入量最低的（46%的卡路里）死亡率要高28%。研究结果在巴塞罗那举行的欧洲心脏病学会会议上公布，并发表在《柳叶刀》杂志上。
“These results point to the fact that human biology is very similar across the globe,” said Dr. Eric Rimm, professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health. “It’s not healthy to eat highly processed carbohydrates no matter where you live.”
哈佛陈曾熙公共卫生学院流行病学和营养学教授埃里克•里姆博士说：“这些结果表明人体生物学在全球范围内都极其相似”。“不论你住在哪儿，食用经高度加工的碳水化合物食物都无益健康”。
In a related paper, the PURE results challenged two widely held beliefs about fruits and vegetables. While most dietary guidelines stress the importance of eating more vegetables, among the PURE participants, eating more fruits, and more seeds and beans, was associated with greater benefits than eating more vegetables. Guidelines also tend to stress that if eating some fruits and vegetables is good, more must be better. But among the study participants, those whose diets included three to four servings of fruits and vegetables a day were no more likely to have died as those whose diets included eight or more servings a day.
在相关论文里面，PURE的调查结果向两个众所周知的蔬果理念发起了挑战。虽然大部分的膳食指南都强调了多吃蔬菜的重要性，但在所有PURE受试者中，多吃水果、种子和豆类，与多吃蔬菜相比，有更大的好处。指南也有倾向性地强调，如果吃一些水果和蔬菜有益，吃更多也一定会更好。但在所有的研究参与者中，每日饮食中包含3到4份蔬果的人不会比包含8份或以上的人更容易死亡。
In a nutshell, a healthy diet based on the PURE results would be rich in fruits, beans, seeds, vegetables, and fats, include dollops of whole grains, and be low in refined carbohydrates and sugars.
简而言之，基于PURE结果的健康饮食将富含水果、豆类、种子、蔬菜和脂肪，也包含大量的全谷物，至于精制碳水化合物和糖类，含量则很低。
“One of the most important take-home messages from the PURE study is that bioactive foods that give rise to new plant life, like fruits and seeds, should be an important part of everyone’s diet,” said Dr. Dariush Mozaffarian, dean of the Tufts Friedman School of Nutrition Science and Policy.
“来自PURE研究的要点之一就是可生长成新生植物的生物活性食物，如水果和种子，都应是每人饮食中的重要组成部分”，来自塔夫茨弗里德曼营养科学与政策学院的Dariush Mozaffarian博士说道。
As an observational study, PURE can’t prove cause and effect. In an effort to eliminate the biases that are common in observational studies, the researchers took blood samples from the majority of the study participants and analyzed them for cholesterol and other lipids. Participants with higher intakes of fats, or lower intakes of carbohydrates, had lower levels of low-density lipoprotein (so-called bad cholesterol) and triglycerides, and higher levels of protective high-density lipoprotein (so-called good cholesterol). Those tests help corroborate the main findings.
作为一项观察性研究，PURE无法证明其是因果关系。为消除观察性研究中常见的偏差，研究人员从大多数研究参与者中抽取血样，并分析他们的胆固醇及其他脂质。具有较高脂肪摄入量，或较低碳水化合物摄入量的受试者，具有较低水平的低密度脂蛋白（所谓的有害胆固醇）和甘油三酯，以及更高水平的保护性高密度脂蛋白（所谓的有益胆固醇）。以上测试都有助于证实主要的研究结果。
The PURE results provide strong support for evidence accumulating over the past decade on what makes a healthy diet, said Mozaffarian. “Cutting back on starch and sugar and adding more fat and more foods from plants, especially bioactive fruits and seeds, is where we should be headed,” he said.
莫扎法瑞安说，PURE的研究结果为过去十年所积累的关于怎样构成健康饮食的证据提供了强有力的支持。他说：“削减淀粉与糖分，并加入更多植物源的脂肪和食物，特别是具有生物活性的水果和种子，是我们应该引领的方向。”
原文标题：Huge new study casts doubt on conventional wisdom about fat and carbs
文章链接：https://www.statnews.com/2017/08/29/fat-nutrition-study/