Systematic reviews in nutrition: standardized methodology.

The objective of this study is to establish a methodological proposal in order to carry out qualitative systematic reviews and apply these findings to a review of Omega-3 Fatty Acids with respect to health and illness. Based on a methodological proposal, a general protocol was developed to provide a sound basis for the preparation of the reviews in this journal supplement. A systematic technique was proposed in order to revise the existing scientific literature on Omega-3 Fatty Acids, with particular emphasis on aspects relating to health and illness. The aim of qualitative systematic reviews is to collate and summarise the results of the primary studies reviewed which will be carried out through a descriptive synthesis. It can be concluded that systematic reviews provide a summary of the existing primary documents on a specific scientific question. The detailed and explicit methods used lead to the identification, critical evaluation and synthesis of the scientific literature. Furthermore, both bias and random effects are reduced, resulting in more reliable data from which to draw conclusions and make recommendations to support decision-making.