Red wine ingredients keep the liver healthy while promoting cardiovascular health

May 30, 2008

     Fresh evidence supports the potential protective health properties of wine ingredients with a US study showing that a glass of red wine a day could actually protect against liver disease. People who drank up to one glass of red win a day saw the risk of liver disease due to Non-Alcoholic Fatty Liver Disease (NAFLD) cut in half, the researchers from California University's San Diego School of Medicine report. They carried out a study of nearly 12,000 individuals.
     NAFLD, almost unknown over two decades ago, is the most common liver disease in the US. Affecting over 40 million Us adults alone, its prevalence is expected to grow worldwide as nations become increasingly obese. Previous research has linked the potential health benefits of wine to its content of Resveratrol, a powerful polyphenol with anti-fungal activity that occurs naturally under the skin of red wine grapes. Resveratrol is touted as the bioactive compound in grapes and red wine, and has particularly been associated with the so-called 'French Paradox', a phrase used to describe the low incidence of heart disease and obesity among the French, despite their relatively high-fat diet and levels of wine consumption.
    The San Diego researcher’s state that recommendations for maintaining modest alcohol consumption in individuals at risk for cardiovascular disease has overlooked the fact that these same people are also at an increased risk for NAFLD. The Californian scientists set out to investigate whether modest alcohol consumption that benefit the heart is safe with regards to the liver since over consumption of alcohol actually causes fatty liver disease. Their findings show "a paradigm shift", in that a daily tipple of one's favorite red may not only be safe for the liver but could actually decrease the prevalence of NAFLD. "The odds of having suspected NAFLD based upon abnormal liver blood tests was reduced by 50 per cent in individuals who drank one glass of wine a day," said Jeffrey Schwimmer, associate professor of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, UC San Diego School of Medicine and Director, Fatty Liver Clinic at Rady Children's Hospital San Diego.
     The result remained constant, even after adjusting for age, sex, race, education, income, diet, physical activity, body mass index, and other markers of health status.
In contrast, compared with red wine drinkers, people who reported modest consumption of beer or spirits had over four times the odds of having suspected NAFLD. The protective properties of compounds found in red wine are the focus of numerous studies today as industry and academia investigate dietary mechanisms to stem the growing tide of diseases such as obesity, heart disease and diabetes. A recent study in California, for example, found low doses of freeze-dried grape powder could inhibit the development of colorectal cancer thanks to the polyphenol Resveratrol and synergistic effects between the grape compounds. Previous studies have also linked Resveratrol to bearing a positive effect on extending survival rates of mice and preventing the negative effects of high-calorie diets.  Resveratrol has also been linked to benefits in diabetes, promoting heart health and fighting obesity.
     In red wine, the amount of Resveratrol in a bottle can vary between types of grapes and growing seasons, and can vary between 0.2 and 5.8 milligrams per liter. But nearly all dark red wines - merlot, cabernet, zinfandel, shiraz and pinot noir - contain Resveratrol. The cross-sectional, population-based study of nearly 12,000 participants in the National Health and Nutrition Examination Survey (NHANES), an epidemiological survey conducted by the Centers for Disease Control and Prevention (CDC), included 7,211 non-drinkers and 4,543 modest alcohol drinkers. The researchers report their surprising findings in the June 2008 issue of the journal Hepatology.