Effects of collagen peptide supplementation on cardiovascular markers: a systematic review and meta-analysis of randomised, placebo-controlled trials.

Previous studies have advocated that collagen peptide supplementation (CPS) can positively affect cardiovascular health. However, the widespread impact of CPS on CVD-related markers is not fully resolved. Consequently, the current systematic review and meta-analysis aimed to assess the efficacy of CPS on CVD-related markers. A systematic search in the Scopus, PubMed and ISI Web of Science databases were completed to identify relevant randomised, placebo-controlled trials (RCT) published up to November 2021. Mean Differences were pooled using a random-effects model, while publication bias, sensitivity analyses and heterogeneity were assessed using previously validated methods. Twelve RCT, comprising of a total of eleven measured markers, were selected for the quantitative analysis. Pooled data revealed that CPS significantly decreased fat mass (-1·21 kg; 95 % CI: -2·13, -0·29; I ² = 0·0 %; P = 0·010) and increased fat-free mass, based on body mass percentage (1·49 %; 95 % CI: 0·57, 2·42; I ² = 0·0 %; P = 0·002). Moreover, collagen peptide supplementation led to a significant decrease in serum LDL (-4·09 mg/dl; 95 % CI: -8·13, -0·04; I ² = 93·4 %; P = 0·048) and systolic blood pressure (SBP) (-5·04 mmHg; 95 % CI: -9·22, -0·85; I ² = 98·9 %; P = 0·018). Our analysis also indicated that CPS did not affect glycemic markers. Our outcomes indicate that CPS reduces fat mass, LDL and SBP while increasing fat-free mass. Future investigations with longer CPS duration are needed to expand on our results.