The evaluation of nightshade elimination diet (NED) on inflammatory and rheumatologic markers of rheumatoid arthritis patients: study protocol for a randomized controlled trial

Abstract

Background and objectives Rheumatoid arthritis (RA) is a chronic disease with the global prevalence rate of 1%. Some RA patients constantly complain about adverse effects they are experiencing after consumption of nightshades. These plants contain Solanine which can cause damage to the bones and joints. Considering the literature, no RCT has been conducted about nightshade effects on RA patients, this study aims to assess the impact of a nightshade elimination diet (NED) on inflammatory and rheumatologic markers of rheumatoid arthritis patients for the first time. Methods A single-blinded controlled trial will be conducted to evaluate the effect of a NED on 36 participants for 8 weeks (2 months). The patients will be equally divided in two intervention and placebo groups. Both groups will receive general anti-inflammatory dietary recommendations and the Intervention group will be undergone a NED during the study. Clinical symptoms will be determined using questionnaires. Moreover, blood samples will be collected from participants to measure desired indicators. Discussion To the best of our knowledge, this study will be the first RCT investigating the effect of NED on inflammatory and rheumatologic markers of rheumatoid arthritis patients. The possible results of this study could be useful for nutritionists and physicians in managing RA patients. Trial registration Iranian Registry of Clinical Trials (irct.ir) IRCT20230220057465N1. Registered on 8 April 2023.