Researchers at the Peter Munk Cardiac Centre of the Toronto General Hospital conducted a study on thirteen volunteers to test whether red wine, proven to be high in polyphenols, differed to other alcoholic drinks in affecting heart health. According to the research, red wine and alcohol consumption were found to have virtually identical impact on health, with one drink of either substance helping to reduce the work rate of the heart. The findings, which are published in the February edition of the American Journal of Physiology, Heart and Circulatory Physiology, could challenge the perception that polyphenol content of red wine is responsible for cardiovascular benefits. Red wine has been linked to extended survival rates of mice and prevented the negative effects of high-calorie diets, in other testing, due to the presence of the polyphenol, resveratrol. The study, supported by Heart and Stroke Foundation of Ontario and the Canadian Institutes of Health Research, was conducted therefore to better understand the link between health benefits and moderate red wine consumption. With population surveys linking lower levels of heart disease to European countries with high-fat diets that also regularly consumed red wine, researchers hoped the testing could better explain this so-called "French paradox." An occasional single serving of red wine, like any other alcoholic beverage was found to improve heart health, according to the researchers. The study said this was the result of alcohol's relaxing affect on blood vessels. However, after a second drink the heart rate, amount of blood being pumped in the body, and sympathetic nervous system action all increased, the study said. At this point, researchers said that blood vessels became less able to expand in response to increased blood flow, reversing any beneficial effects obtained by a consumer after a single serving of wine or alcohol. Researcher Dr. John Floras said that findings from the testing had thrown up some unexpected results. "We had anticipated that many of the effects of one ethanol drink would be enhanced by red wine," he stated. "What was most surprising was how similar the effects were of red wine and ethanol." Floras added that that the American Heart Association (AHA) did not recommend consuming a single red wine or alcoholic drink as a means of improving hearth health, as long-term affects of continued consumption were unknown. "Our findings point to a slight beneficial effect of one drink - be it alcohol or red wine - on the heart and blood vessels, whereas two or more drinks would seem to turn on systems that stress the circulation," he stated. "If these actions are repeated frequently because of high alcohol consumption these effects may expose individuals to a higher risk of heart attacks, stroke or chronic high blood pressure." All 13 participants in the study were aged between 24 to 47 years of age. These respondents, consisting of a group of seven males and six females, were all selected as healthy non-smokers, who were neither heavy drinkers or abstainers. The participants attended three separate morning sessions in which they consumed a set standard drink of red wine, ethanol or water on a random, single-blind basis, two weeks apart. The standard drink was a either a 4 ounce (120ml) serving of red wine or a 1.5 ounce (44ml) spirits shot. The wine used in the trial was a moderately priced pinot noir with a verified high t-resveratrol content, selected by The Quality Assurance Laboratory of the Liquor Control Board of Ontario, the researchers said. Source: American Journal of Physiology, Heart and Circulatory Physiology, Volume 294, Pages 605-612, doi:10.1152/ajpheart.01162.2007 "Dose-related effects of red wine and alcohol on hemodynamics, sympathetic nerve activity, and arterial diameter" Authors: John S. Floras, Jonas Spaak, Anthony C. Merlocco, et al.