Lycopene and tomato and risk of cardiovascular diseases: A systematic review and meta-analysis of epidemiological evidence

Background and aims: Worldwide, cardiovascular diseases (CVDs) remains as the main cause of mortality. Observational studies supports an association between intake of tomato products or lycopene with a reduced CVDs risk. Our aim was to undertake a systematic review and meta-analysis of the evidence on the topic.

Methods: Medline, Web of Science, and Scopus were searched from inception until July 2017. We included longitudinal and cross-sectional studies reporting associations between lycopene and tomato consumption and cardiovascular morbidity and mortality among adult subjects. Random-effects models were used to determine the pooled effect sizes.

Results: Twenty-eight publications met our inclusion criteria and 25 studies provided quantitative data for meta-analysis. Results showed that individuals in the highest consumption category of, or with the highest serum concentration of, lycopene had significantly lower risk of stroke (hazard ratio (HR) 0.74, 0.62–0.89, p = 0.02; I² = 32) and CVDs (HR 0.86, 0.77–0.95, p = 0.003; I² = 0). In addition, individuals categorised in the highest serum concentration of lycopene also had significantly lower risk of mortality (HR 0.63, 0.49–0.81, p<0.001; I² = 46). Lycopene was not significantly associated with myocardial infarction, while scarce evidence on the association of lycopene with atherosclerosis, congestive heart failure, or atrial fibrillation was evident. Evidence from three studies suggested that higher intakes of tomato were associated with non-significantly lower stroke, CVDs and CHD.

Conclusions: This comprehensive meta-analysis suggests that high-intakes or high-serum concentration of lycopene are associated with significant reductions in the risk of stroke (26%), mortality (37%) and CVDs (14%).