Clinical nutrition – AEAS精读 (Y10-12)

The history of clinical nutrition, or the study of the relationship between health and how the body takes in and utilizes food substances, can be divided into four distinct eras: the first began in the nineteenth century and extended into the early twentieth century when it was recognized for the first time that food contained constituents that were essential for human function and that different foods provided different amounts of these essential agents. Near the end of this era, research studies demonstrated that rapid weight loss was associated with nitrogen imbalance and could only be rectified by providing adequate dietary protein associated with certain foods.

The second era was initiated in the early decades of the twentieth century and might be called “the vitamin period.” Vitamins came to be recognized in foods, and deficiency syndromes were described. As vitamins became recognized as essential food constituents necessary for health, it became tempting to suggest that every disease and condition for which there had been no previous effective treatment might be responsive to vitamin therapy. At that point in time, medical schools started to become more interested in having their curricula integrate nutritional concepts into the basic sciences. Much of the focus of this education was on the recognition of vitamin deficiency symptoms. Herein lay the beginning of what ultimately turned from ignorance to denial of the value of nutritional therapies in medicine. Reckless claims were made for effects of vitamins that went far beyond what could actually be achieved from the use of them.

In the third era of nutritional history in the early 1950’s to mid-1960s, vitamin therapy began to fall into disrepute. Concomitant with this, nutrition education in medical schools also became less popular. It was just a decade before this that many drug companies had found their vitamin sales skyrocketing and were quick to supply practicing physicians with generous samples of vitamins and literature extolling the virtue of supplementation for a variety of health-related conditions. Expectations as to the success of vitamins in disease control were exaggerated. As is known in retrospect, vitamin and mineral therapies are much less effective when applied to health-crisis conditions than when applied to long-term problems of undernutrition that lead to chronic health problems.

 

临床营养学的历史,或研究之间的关系健康与身体如何接受和利用食品物质,可分为四个不同的时期:第一次开始于19世纪,延续到二十世纪初的时候首次承认,食品中成分,是人类必不可少的功能,不同的食物提供不同数量的这些基本代理。在这个时代即将结束的时候,研究表明,快速减肥与氮平衡有关,只有提供与某些食物相关的足够的膳食蛋白质才能纠正。

第二个时期开始于20世纪初的几十年,可能被称为“维生素时期”。维生素开始在食物中被发现,缺乏症也被描述出来。随着维生素被认为是健康所必需的基本食物成分,人们开始倾向于认为,以前没有有效治疗的每种疾病和状况都可能对维生素治疗有反应。那时,医学院开始对将营养概念融入基础科学课程更感兴趣。这种教育的重点主要是认识到维生素缺乏的症状。这就是从无知到否认营养疗法在医学上的价值的开始。有人轻率地声称维生素的功效远远超出了使用维生素的实际效果。

在1950年代初到1960年代中期营养史上的第三个时期,维生素疗法开始声名狼藉。与此同时,医学院的营养教育也变得不那么受欢迎。就在10年前,许多制药公司发现他们的维生素销售直线上升,并迅速向执业医生提供了大量的维生素样本,以及颂扬各种健康相关疾病补充维生素好处的文献。对维生素在疾病控制方面成功的期望被夸大了。回顾过去,维生素和矿物质疗法在治疗健康危机时的效果远不如在治疗导致慢性健康问题的长期营养不良问题时的效果。