The effects of polyphenols from grapes to prevent cardiovascular disease

Abstract

Background: Cardiovascular disease is the leading cause of mortality and morbidity in the world and has something to do with daily diet. The polyphenol is the most abundant compound in daily diet, including grape. The red wine was rich in polyphenol because of composing much grape. Early study has already confirmed the “French Paradox” in cardiovascular protection power, which shed light on the dietary modulation on disease. Objective: The main objective of the study was to evaluate the effect of products containing polyphenol such as red wine extract, grape juice and grape extract tablets or powder on cardiovascular disease risk factors. It mainly examined relationship between polyphenol and serum lipid in addition to blood pressure. Methods: Studies working on effects of grape extract products on cardiovascular disease were searched from electronic resources MEDLINE and EMBASE. Nine clinical controlled trials were identified through PubMed and Ovid. CONSORT guideline and Jadad Score were used to appraise the quality of trials. Weighing two assessment guidelines, a total of three studies were in good quality, one was in bad quality while the rest four were fair to middle. Results: The changes before and after intervention on serum lipid and blood pressure were contradictory. Some studies found polyphenol was statistically significant protective factors, while some did not find it siginificant but still showed a protective effect. One study found polyohenol had no effect on cardiovascular disease risk factors. Conclusion: The prevention of polyphenol was not consistent in nine trials and there is no sufficient and strong evidence supporting its cardiovascular protection effect given that the study design of each trial differed. It was not recommeded to use grape polyphenol as cardiovascular protect products. There were limitations and weakness of current study on the association of polyphenol and cardiovascular disease. Further research on this topic is required, both in vivo and in vitro.