Flavonoids in beer and their potential benefit on the risk of cardiovascular disease

Beer is a popular alcoholic beverage and its consumption is characterized by a U- or J-shaped relation to the risk of cardiovascular disease (CVD). In addition to the ability of ethanol to elevate high-density lipoprotein-cholesterol, other constituents of beer, including flavonoids, may also contribute to its association with a reduced risk of CVD among moderate drinkers. Flavonoids are ubiquitous in plant-based foods and an integral part of any diet that includes fruits, vegetables, whole grains and/or beverages derived from them. Six classes of flavonoids, including 31 specific compounds, have been characterized in beer with a wide range of concentration, from 0.001 to 20 mg/l, likely due to variations in the barley and hops, brewing and stabilization processes, and duration of storage. The principal flavonoids in beer are isoxanthohumol, catechin, catechin gallate, epicatechin gallate, kaempferol, quercetin, procyanidin B3, and prodelphidins B3 and B9. Flavonoid intake has been demonstrated to impact an array of biochemical and functional actions in animal models and human studies that are associated with ameliorating CVD risk, such as reducing angiogenesis, cholesterol, inflammation, oxidative stress, and thrombogensis as well as promoting vascular reactivity. Nonetheless, definitive studies on the direct contribution of flavonoids to the benefit of moderate beer consumption on CVD remain to be undertaken.