Many
fruits and vegetables have been found to have a protective effect against
cardiovascular diseases. We conducted a systematic review and meta-analysis to
determine the relationship between apple or apple polyphenol intake and
cardiovascular disease risk. The PubMed, Embase, Cochrane, and Web of Science
databases were searched up to August 4, 2020. Studies that had an intervention
time of 1 week; used apple or apple polyphenols as the intervention; were
designed as a randomized controlled trial; and measured blood pressure,
cholesterol, and blood glucose levels were included. The meta-analysis showed
that the group with apple or apple polyphenol intake had significantly higher
high-density lipoprotein levels (standardized mean difference [SMD] = 0.34, 95%
confidence interval [CI] [0.01, 0.67], p = 0.0411, = 77%,
random-effects model) and significantly lower C-reactive protein levels (SMD =
–0.43, 95% CI [–0.65, –0.20], p = 0.0002, = 18%,
fixed-effects model) than the control group, indicating that the intervention
reduced the risk of cardiovascular diseases. Apple or apple polyphenol intake is
associated with a reduced risk of cardiovascular diseases. These results are
consistent with the old saying that eating an apple a day can help keep the
doctors away.