2.3. Selection strategy:
After computerized search, titles and received papers abstracts were screened by the search strategy. Two authors (LG and M.M) selected articles based on the inclusion criteria independently. Articles including eligibility criteria in the title and abstract screening were elected to be checked by full manuscript. Parallel clinical trials were elected by applying a control group or crossover design in the systematic review and meta-analysis. All classified trials were retrieved by either of the authors. According to the data within the full information, we used a form to elect the studies eligible for inclusion in the meta-analysis. Contradictions between the authors were solved by consensus or third researcher.