Does strawberry supplementation ameliorate markers of cardiovascular and metabolic health? A systematic review and meta-analysis

Purpose This study aims to identify the effect of strawberry supplementation on some metabolic, inflammatory and oxidative parameters in adults with cardiovascular (CV) risk factors. Design/methodology/approach A systematic literature search was performed up to November 2020 using PubMed, Embase, Cochrane, Web of Sciences and Scopus databases. The pooled mean difference (MD) with 95% confidence interval (CI) was used to analyze the data by random-effects model. I2 statistics and Cochrane risk of bias tool were used for investigating heterogeneity and quality of included studies, respectively. Findings In total, 13 randomized controlled trials with 488 participants were included. Strawberry supplementation significantly reduced diastolic blood pressure (MD = −2.1, 95% CI [−3.7, −0.42], P = 0.01), low-density lipoprotein cholesterol (−0.16, −0.30, −0.02, P = 0.03), high-sensitivity C-reactive protein (CRP) (−0.76, −1.4, −0.05, P < 0.001) and CRP (−0.31, −0.43, −0.18, P = 0.04). Leptin levels were raised in control group compared with participants who had received strawberry (0.65, 0.09 and 1.2, P = 0.02). The results of subgroup analysis based on the follow-up duration and supplementation dose showed that consumption of strawberry for more than eight weeks and 50 g day−1 can significantly decrease some other CV risk factors compared to control group. Further, both higher follow-up duration and supplementation dose were more effective in increasing leptin levels of control group compared to intervention group. Originality/value The use of some useful plant foods such as strawberries by the pharmaceutical industry and the community health sector can greatly help improve people’s CV and metabolic health.