Effects of lycopene intake on HDL‐cholesterol and triglyceride levels: A systematic review with meta‐analysis

Lycopene is a lipophilic unsaturated carotenoid and has a very strong singlet oxygen‐quenching ability. Increased serum or plasma lycopene levels have been reported to be associated with a lower risk of metabolic syndrome. We aimed to investigate the effects of lycopene intake on blood HDL‐cholesterol (HCL‐c) and triglyceride (TG) levels, which are metabolic syndrome biomarkers, by systematic review and meta‐analyses of human interventional trials. We searched 15 databases and included studies that assessed the effects of oral lycopene intake on blood HDL‐c and TG levels of participants ≥18 years of age. Three reviewers independently selected applicable studies, then assessed study qualities. Data were pooled as standardized mean difference (SMD) and analyzed by random‐effects model. Heterogeneity was assessed by I2 statistics. Meta‐analysis including 12 trial arms (n = 781) revealed a significantly increased HDL‐c level in the lycopene group compared with that in the control group (SMD = 0.33 [95% CI: 0.12, 0.54], p = 0.002) and moderate heterogeneity (I2 = 45%). Most subgroup meta‐analyses (restricted to study design, test food type, intake period, and participants’ characteristics) showed similar results for HDL‐c level. On the other hand, meta‐analysis including 11 studies (n = 854) revealed no significant difference in TG level between the lycopene and control groups. Most studies which met eligibility criteria had moderate risk of bias. Funnel plots for HDL‐c and TG suggested an absence of publication bias. In conclusion, this systematic review and meta‐analyses suggested that lycopene intake significantly improved blood HDL‐c levels but not TG levels.