Potential Bladder Irritants and Overactive Bladder in Women: A Systematic Review

Objectives: The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) website indicates that “many people find that alcohol; spicy foods; chocolate; artificial sweeteners; caffeinated, carbonated, and citrus beverages; and high-acid foods, such as citrus and tomatoes, may contribute to bladder irritation.” We conducted a systematic review of the association between these six potential bladder irritants and symptoms of overactive bladder (OAB) among adult women, including urge urinary incontinence (UUI), urgency, frequency, and nocturia.

Methods: A systematic review of the literature was conducted through MEDLINE, EMBASE and SCOPUS according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Studies from respective database initiation to July 2023 were included. An adapted version of the patient-intervention-comparison-outcome criteria was used for the search. We concentrated on the criteria Patient (females with OAB/UUI, urgency, frequency, and nocturia), Intervention/exposure (intake of potential bladder irritants as described), Comparison (less/no intake) and Outcome (differences in symptoms). References of included articles were hand-searched for additional relevant citations. Publications on instrument development, editorials, commentaries, and review articles were excluded. The risk of bias was assessed using the Risk of Bias in Non-randomized Studies – of Exposures, or ROBINS-E tool. Two reviewers screened abstracts and full texts. Three reviewers independently extracted data. Any discrepancies were adjudicated with a fourth reviewer. Covidence software was used for data extraction. Meta-analysis was not conducted, given the heterogeneity of studies. The study was registered in the International Prospective Register of Systematic Reviews in 2023 (CRD4202346625). This study was considered IRB-exempt by the Johns Hopkins IRB.

Results: A total of 11,156 abstracts were screened and 47 articles met inclusion criteria (Figure 1). Forty-four of the 47 included studies were observational (Table 1). Among the 47 studies, most addressed alcohol (n=32) or caffeinated, carbonated and citrus beverages (n=25). A small number of studies addressed spicy foods (n=1), chocolate (n=3), artificial sweeteners (n=5), or high-acid foods (n=2). A number of urinary symptoms were considered, including OAB (n=15), UUI (n=16), urinary urgency, frequency, and nocturia (n=25). Overall, the observed associations were mixed and inconsistent across studies. We did, however, observe a consistent lack of association between alcohol and UUI (n=8). The risk of bias was moderate in 21 publications and low in the remaining 26 publications. Of the 21 publications with moderate risk of bias, 16 were due to unclear risk from handling of missing data and source of funding/conflicts of interest. Of the remaining 5 publications with moderate risk, two were high risk for missing data, two were high risk for measurement of exposure, and one was high risk for selection of participants.

Conclusions: This systematic review failed to identify consistent evidence of an association between any of these six potential bladder irritants and symptoms of OAB.