Efficacy and safety of bromelain: A systematic review and meta-analysis

Background: Pineapple has an important role in ethnopharmacology and its enzyme, bromelain, has been extensively investigated for its medicinal properties. Aim: This systematic review and meta-analysis aimed to assess clinical evidence concerning the efficacy and safety of bromelain. Methods: A systematic search was conducted from conception to August 2022 using CINAHL Complete, MEDLINE, ScienceDirect, Scopus, and Thai Journal Online (TJO). The risk of bias was assessed using Risk of Bias 2 or ROBIN-I. A random-effect model with inverse variance weighting and DerSimonian and Laird method was used for meta-analysis. The heterogeneity was evaluated by I-2 statistics. Results: We included 54 articles for qualitative summary and 39 articles for meta-analysis. The systematic review found that bromelain presented in serum with retained proteolytic activity after oral absorption. Bromelain may be effective against sinusitis but was not effective for cardiovascular diseases. Pain reduction from oral bromelain was slightly but significantly better than controls (mean difference in pain score = -0.27; 95% CI: -0.45, -0.08; n = 9; I-2 = 29%). Adverse events included flatulence, nausea, and headache. Topical bromelain significantly reduced the time to complete debridement (mean difference in time = -6.89 days; 95% CI: -7.94, -5.83; n = 4; I-2 = 2%). Adverse events may be irrelevant and include burning sensation, pain, fever, and sepsis. Conclusions: Moderate-quality studies demonstrated the potential of oral bromelain in pain control and topical bromelain in wound care. Major health risks were not reported during the treatment with bromelain.