Blessings of the grape

Numerous epidemiological studies have shown an inverse correlation between moderate consumption of alcoholic drinks and the risk of coronary heart disease. Wine, especially red wine, may be more favorable in this respect than beer or spirits because of its high content of flavonoids. These polyphenols originate from the skins, seeds, and vine stems of the grapes while some are formed during the process of vinification. In nature they exhibit a wide range of biological effects as antioxidants, antimicrobials, and modulators of various enzyme systems. Potential beneficial effects for humans have been demonstrated in experimental studies and include influences on the oxidation of LDL-cholesterol, on platelet aggregation, and on prostaglandin and nitric oxide metabolism. However, most of these studies concern semi in vivo experiments and research in animal models; data from human intervention trials are scarce. Furthermore, little is known about the absorption, bioavailability, and bioactivity of most of these compounds because of difficulties in reliable quantification in biological fluids. Until these issues are well addressed, and despite the enthusiasm and faith of many believers, evidence-based medicine justifies a critical attitude towards the application of these compounds outside the context of scientific research. Yet, there is no need to deny their potential, nor should we close our eyes to the blessings of the grape.