Relationship between diet and ankylosing spondylitis: A systematic review.

The question of whether diet plays a role in the onset of ankylosing spondylitis (AS) or can affect the course of the disease is an important one for many patients and healthcare providers. The aims of this study were to investigate whether: 1) patients with AS report different diets to those without AS; 2) amongst patients with AS, diet is related to severity; 3) persons with particular diets are less likely to develop AS; 4) specific dietary interventions improve the AS symptoms. The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Medline, Embase, Cochrane Library, and reference lists of relevant articles were searched. Two authors independently selected eligible studies, assessed the quality of included trials, and extracted the data. Sixteen studies (nine observational and seven interventions) were included in the review. Due to the heterogeneity of the study designs and analyses, the results could not be aggregated. Evidence on a possible relationship between AS and diet is extremely limited and inconclusive due to the majority of included studies being small, single studies with moderate-to-high risk of bias, and insufficient reporting of results.
Competing Interests: Conflict of Interest: TVM reports grant from National Ankylosing Spondylitis Society (NASS), during the conduct of the study. GJM reports grant from NASS, during the conduct of the study; and GJM is Chief Investigator of the British Society for Rheumatology (BSR) Biologics Register in Ankylosing Spondylitis. The BSR receives or has received funds for the conduct of this register from Pfizer, AbbVie and UCB. No conflict of interest was declared by the other authors.