Evidence-based criteria in the nutritional context

Abstract

During the last decade, approaches to evidence-based medicine, with its heavy reliance on the randomized clinical trial (RCT), have been adapted to nutrition science and policy. However, there are distinct differences between the evidence that can be obtained for the testing of drugs using RCTs and those needed for the development of nutrient requirements or dietary guidelines. Although RCTs present one approach toward understanding the efficacy of nutrient interventions, the innate complexities of nutrient actions and interactions cannot always be adequately addressed through any single research design. Because of the limitations inherent in RCTs, particularly of nutrients, it is suggested that nutrient policy decisions will have to be made using the totality of the available evidence. This may mean action at a level of certainty that is different from what would be needed in the evaluation of drug efficacy. Similarly, it is judged that the level of confidence needed in defining nutrient requirements or dietary recommendations to prevent disease can be different from that needed to make recommendations to treat disease. In brief, advancing evidence-based nutrition will depend upon research approaches that include RCTs but go beyond them. Also necessary to this advance is the assessing, in future human studies, of covariates such as biomarkers of exposure and response, and the archiving of samples for future evaluation by emerging technologies.

A multidisciplinary reconstruction of Palaeolithic nutrition that holds promise for the prevention and treatment of diseases of civilisation

“…Despite some compelling examples of the healthy lifestyles of traditional populations, current dietary recommendations derive preferably from randomised clinical trials with single nutrients and preferably hard endpoints (352) . This approach clearly oversimplifies the effects of dietary nutrients (353) , since neither macronutrients, nor micronutrients, are consumed in isolation and their effects may be the result of a complex web of interactions between all the nutrients present in the biological systems that we consume, such as a banana or a fish.…”

Chromium supplements for glycemic control in type 2 diabetes: limited evidence of effectiveness

“…In contrast, drug effects tend to be monovalent, monotonic, and larger in their effect sizes and have responses that vary in proportion to dose. 70 Standardized procedures have been developed to support provision of the evidence needed for credible systematic reviews involving dietary constituents, 10,71,72 but not all published systematic studies or meta-analyses use them.…”

¿Bueno para la salud? Un análisis de los requisitos de sustanciación científica en la regulación europea de las declaraciones de salud

“…En el caso de las declaraciones de salud, como se ha visto, la CE y la EFSA establecen un determinado nivel de prueba al exigir datos de estudios de intervención en humanos, particularmente procedentes de pruebas controladas aleatorizadas (RCT por sus siglas en inglés). Hay varios autores 1,[20][21][22] que consideran que el formato metodológico de los RCT es adecuado sólo para el ámbito de los ensayos de medicamentos (del que proviene), pero no para el de los alimentos; entre otras razones porque mientras los medicamentos tienen el objetivo de curar personas enfermas, los alimentos funcionales son para el consumo de personas generalmente sanas. Una de sus implicaciones es que resulta difícil o incluso imposible diseñar grupos de control adecuados para estudios RCT sobre alimentos.…”