Nutrición basada en la evidencia: presente, limitaciones y futuro

Abstract

Evidence-based medicine (EBM) is currently the safest and most reliable way to practice clinical medicine. One of the most widely accepted definitions includes the three main principles of EBM: scientific evidence, clinical experience and the needs and values of the patient. Since its introduction in 1992, EBM has been incorporated into the various medical specialties, although major criticisms and obstacles to its generalization have also appeared. Among the factors involved in our difficulty in implementing EBM are our traditional training as physicians, the sheer quantity of scientific literature published and the type of sources that we are used to consulting when faced with the problems of daily clinical practice. The most frequent arguments leveled against EBM are that it is reductionist or simplistic and, according to its critics, that it gives scant importance to clinical experience. Although it is difficult to admit, the characteristic of EBM that probably arouses the strongest criticism is the absence of a universal and absolute truth: the conclusions that can be reached through EBM are always preceded by a description of the main investigation analyzed; new results can (and should) modify our clinical practice. Systematic reviews of the literature and clinical practice guidelines, as instruments by themselves, facilitate the implementation and development of EBM. In addition to the limitations of EBM, evidence-based nutrition (EBN) faces a series of specific problems mainly related to the difficulties of study designs, the scarce scientific evidence available, and the quality scales and levels of evidence used. To understand these problems, they should be analyzed independently in clinical nutrition and community nutrition, while clinical nutrition should be approached by separating it into its two branches: the need to feed-maintain nutritional status, and the use of nutrition as a therapeutic modality capable of modifying the course of a disease. The present article reviews the concepts, applications and limitations of EBN and its applications in the field of nutrition. “Half of what we teach them will be proved to be false in the next 10 years. The problem is that none of their teachers know which half this will be”. Dr. Sydney Burwell, Dean of the Faculty of Medicine of Harvard University (Taken from “Sackett DL., Straus ShE., Richardson WS, Rosenberg W, Haynes RB. Evidence Based Medicine. How to Practice and Teach. Churchill Livingstone. Edinburgh 2000 (2 nd edition).