Effects of propolis consumption on blood pressure, lipid profile and glycemic parameters in adults: a GRADE-assessed systematic review and dose–response meta-analysis

Systematic review and dose-response meta-analysis of randomized controlled trials in adults with a range of health statuses, including healthy participants and patients with type 2 diabetes, dyslipidemia, NAFLD, chronic kidney disease, metabolic syndrome, PCOS, rheumatoid arthritis, obesity, and related conditions. The included trials were conducted in multiple countries and lasted at least 4 weeks.

Oral propolis was tested across the included randomized trials in capsules, tablets, pills, solutions, or drops. Doses ranged from 226.8 to 2000 mg/day, or 1 to 30 drops, for 4 to 48 weeks; most comparisons used placebo or another control, and a few trials also paired propolis with diet or exercise as part of the active regimen.

Propolis was associated with favorable changes in several cardiometabolic outcomes, especially triglycerides, LDL-cholesterol, HDL-cholesterol, fasting glucose, HbA1c, insulin, HOMA-IR, and systolic blood pressure. In the pooled analysis, TAG fell by WMD -10.44 mg/dl (95% CI -16.58, -4.31; P = 0.001), LDL-cholesterol by -9.31 mg/dl (95% CI -13.50, -5.12; P < 0.001), HDL-cholesterol increased by 2.03 mg/dl (95% CI 0.24, 3.83; P = 0.02), and SBP decreased by -2.24 mmHg (95% CI -4.08, -0.39; P = 0.01). There was no significant effect on total cholesterol or diastolic blood pressure. The authors also reported non-linear dose-response patterns, with some benefits appearing at doses <1000 mg/day and others at >=1000 mg/day.

Substantial heterogeneity was present for several outcomes, with I2 values often high, reflecting variability in propolis preparations, doses, populations, and study designs. Many trials were relatively small and short, and the review included diverse clinical groups and cointerventions in some arms, which limits generalizability and makes the overall evidence less uniform despite generally favorable findings.