Effects of Capsicum annuum supplementation on the components of metabolic syndrome: a systematic review and meta-analysis

Systematic review and meta-analysis of randomized controlled trials assessing Capsicum annuum supplementation in adults (≥18 years), mixed gender; overweight/obese (BMI ≥25 kg/m2) and some healthy (BMI <25 kg/m2); parallel-arm and crossover RCTs; 12 studies included in the systematic review; 11 included in meta-analysis (n ≈ 609).

Capsicum annuum derivatives given orally in multiple regimens across trials for 4–12 weeks: fresh chili pepper (30 g/day); chili powder (1.25 g/day; ~5 mg capsaicin); fermented red pepper paste (kochujang/FRPP) in pill form (32 g FRPP containing ~11.9 g FRPP); dihydCapsiate/capsinoid capsules (3–9 mg/day); capsinoids capsules (9 mg/day); Capsimax capsules (2–4 mg capsaicinoids/day).

LDL-cholesterol decreased significantly with Capsicum annuum supplementation (SMD −0.39; 95% CI −0.72 to −0.07; P = 0.02). Body weight showed a non-significant trend toward reduction (SMD −0.19; 95% CI −0.40 to 0.03; P = 0.09). No significant effects on triglycerides, HDL-cholesterol, or total cholesterol. Authors conclude that larger, well-designed clinical trials are needed to confirm efficacy and safety for metabolic syndrome; findings suggest potential LDL reduction and possible weight change but evidence is limited by heterogeneity and risk of bias.

Small number of eligible studies; heterogeneity in intervention forms, doses, durations, and populations; several studies with risk of bias; short durations (4–12 weeks); limited adverse event reporting; not registered in PROSPERO; potential publication bias not assessed.