A pilot randomized controlled trial to assess the feasibility of a sham anti-inflammatory diet: Can inflammation neutrality and participant blinding be achieved?

Context: While randomized, double-blind, placebo-controlled trials are the gold standard for investigating the effects of dietary interventions, the complexity of designing such trials has limited their use. Study Design: Single centre, randomized, double-blind, controlled trial. Objective: Primary objectives included the assessment of the impact of a sham anti-inflammatory diet on inflammation and participant blinding. Methods: : This dietary advice trial involved participants with spinal cord injury (SCI), randomized to either a sham-diet condition (n=8) or non-dieting control condition (n=8). Participants in the sham-diet group were told they would be randomized to either an anti-inflammatory diet condition, or a sham diet designed to be inflammation-neutral. Participants randomized to the sham-condition completed a diet consultation prior to beginning the diet for a period of 4-weeks. Primary outcomes of interest included the change in inflammation as assessed by plasma concentrations of C-reactive protein (CRP), and participant blinding assessed upon completion of the trial. Results: : All members of the control group and 6 of 8 members of the sham-diet group completed the intervention. Blinding was successful as all 6 members who completed the sham-diet believed they were on the true anti-inflammatory diet. Further, the sham diet was shown to have no significant effect on inflammation over the 4-week intervention period as demonstrated by plasma CRP concentrations. Conclusion: This pilot study provides preliminary evidence for the utility of a sham-anti-inflammatory diet and could be used to strengthen the design of future dietary interventions utilizing anti-inflammatory diets.