Eating watermelon appears to have cardiovascular benefits, with the results of a systematic review and meta-analysis showing that the fruit has potential antihypertensive effects.
For the systematic review and meta-analysis, researchers searched Cochrane Library databases, ISI Web of Science, PubMed, and Scopus for randomized controlled trials (RCTs) in which the effects of watermelon supplementation on cardiovascular disease risk factors were evaluated.
The initial search yielded 8,962 studies, of which nine were included in the final analysis. A random-effect model was applied to compute weighted mean differences, while standard methods were used to examine publication bias, sensitivity analysis, and heterogeneity.
Pooled data showed promising evidence of the antihypertensive effect of watermelon. Specifically, watermelon consumption led to a significant reduction in systolic blood pressure, total cholesterol, and low-density lipoprotein.
However, intake of watermelon resulted in a significant increase in fasting blood sugar levels.
There was no significant difference in other outcomes of interest such as diastolic blood pressure, heart rate, body mass index, body fat, and serum levels of arginine, insulin, and C-reactive protein after watermelon supplementation.
The researchers advised caution when interpreting the result regarding the remaining outcomes due to the lack of evidence in humans. Additional RCTs with longer follow-ups and larger sample sizes should be performed to validate the current findings.