Evidence Level
Propolis is a natural substance with a growing body of clinical evidence supporting its health benefits. A well-designed randomized controlled trial (RCT) by Cohen et al. (2004) demonstrated that propolis significantly reduced upper respiratory infections in children during winter. Sforcin (2007) conducted a comprehensive review, confirming propolis's antimicrobial properties against bacteria, viruses, fungi, and parasites, as well as its anti-inflammatory and immunomodulatory effects.
Recent studies have further elucidated propolis's benefits. Chang et al. (2025) found that propolis significantly reduced oral mucositis in chemotherapy patients (OR 0.35, P=0.003). Bahari et al. (2025) conducted a systematic review and meta-analysis of 12 RCTs involving 605 adults, showing that propolis consumption significantly improved lipid profile, glycemic parameters, and systolic blood pressure. Qu et al. (2025) also found that propolis supplementation reduced systolic blood pressure (WMD=-5.58 mmHg).
Propolis has demonstrated anti-inflammatory effects in multiple studies. Zhong-Yong et al. (2024) meta-analyzed 20 RCTs with 1139 participants, finding significant reductions in IL-6 and TNF-α levels. Gholami et al. (2024) further confirmed these findings in a systematic review of 17 studies.
Despite its benefits, propolis research faces challenges due to variability in composition based on geographic origin, bee species, and plant sources. Brazilian green propolis and European poplar-type propolis are the most studied varieties.