|Wine, alcohol and health research: an in-depth look - United States
Every month, new, valid research findings on alcohol, health and social issues are being published in peer-reviewed journals. This is driven by the scientific community around the world, which is continuing investigations to resolve the many unanswered questions on exactly why sensible consumption may contribute to a positive lifestyle.
The most significant findings in recent months have focused on coronary heart disease (CHD). These data have emerged from leading U.S. studies, the Harvard Physicians Health Professionals Study and the Kaiser Permanente Cohort Study. New research conclusions have important clinical implications, as they look more closely at the importance of drinking patterns, beverage-specific findings and the best advice to the public.
The scientific debate remains intriguing, as studies clearly find favorable effects from all beverages containing alcohol and point to some specific results for wine. The ongoing Copenhagen City Heart Study in Denmark takes the most comprehensive look at wine drinkers, their lifestyle habits and disease patterns.
The following outlines the most recent findings from these three cohorts and presents the data from the Danish cohort in more detail.
Recent Findings From U.S. Studies: Harvard University And Kaiser Permanente
The pattern of alcohol consumption, long thought to play a role in alcohol's reported association with reduced risk of heart disease, received strong statistical confirmation from the ongoing Harvard study on male health professionals. The recent data, published in the New England Journal of Medicine, shows that men who drank at least three and up to seven days a week reduced their risk of heart attack by nearly a third when compared to men who drank less than once a week. "The risk was similar among men who consumed less than l0g of alcohol per drinking day and those who consumed 30g or more. No single type of beverage conferred additional benefit, nor did consumption with meals," state lead author Dr. Kenneth J. Mukamal and colleagues. The researchers generally cautioned about the dangers of heavy drinking as well as the possible increased risk of breast cancer for women at even moderate levels.
Over the last decade, many Harvard University research studies have reported benefits among sensible drinkers with no significant beverage-specific differences. Dr. Eric Rimm from Harvard University published a review study in 1996 in the British Medical Journal that has been widely acknowledged among the research and public health community. He concluded, "Results from observational studies, where individual consumption can be assessed in detail and linked directly to coronary heart disease, provide strong evidence that a substantial proportion of benefits of wine, beer or spirits are attributable primarily to the alcohol content rather than to other components of each drink."
He also wrote, "Most of the differences in findings regarding specific drink types are probably due to differences in drinking patterns..." This position is reflected not only in findings from Harvard University but also in other U.S. cohorts such as the Framingham Heart, the American Cancer Society and the Kaiser Permanente studies.
The most comprehensive beverage-specific research in the U.S. is being conducted at Kaiser Permanente in Oakland, Calif., under the leadership of Dr. Arthur Klatsky, who has been a pioneer in alcohol and coronary heart disease research. He has published dozens of important articles on alcohol and health. At the recent American Heart Association (AHA) meeting, Klatsky released new findings on the relation between total alcohol intake and frequency (days/ week) of moderate wine (white and red), beer and spirits consumption to coronary heart disease mortality.
The official AHA abstract explains that all three beverages have CHD benefits but also states, "Drinkers of any type of wine have lower CHD mortality risk than beer or liquor drinkers, but it remains unclear whether this is due to nonalcoholic ingredients of wine, to drinking pattern or to associated traits." It is also discussed that the similar or slightly more pronounced effects of white wine compared to red wine make red wine phenolics an unlikely explanation for the different effects observed for moderate wine drinking preferrers.
Specifically, Klatsky found in this new study that those drinking wine daily had about a 25% lower risk of CHD death than did those who drank the same amount of beer and 35% less compared to those who drank comparable amounts of spirits. Klatsky and his colleagues published a 1990 study on the risk of CHD death and a 1997 study on the risk of CHD hospitalization, which found wine and beer drinkers had a lower CHD risk than spirits drinkers. This research pointing to benefits for all beverages and some unique findings for wine has been partly responsible for other in-depth research investigations around the globe.
The World's Most Prominent Wine-Specific Study: The Copenhagen Heart Study
As the scientific debate continues, research investigations in Europe, and specifically Denmark, point to a number of wine-specific findings that are somewhat different from those found in the U.S. The Copenhagen City Heart Study lead by Dr. Morten Gronbaek looks at several disease outcomes and beverage choice based on data from the Danish government's Institute for Preventive Medicine.
Within the last decade, published data from the Danish cohort associates moderate alcohol consumption with several favorable health outcomes and reports specifically on wine and a reduced risk of all cause mortality. The landmark Copenhagen City Heart Study was published in 1995 in the British Medical Journal, concluding, "Low to moderate intake of wine is associated with lower mortality from cardiovascular and cerebrovascular disease and other causes."
The results showed that the risk of dying steadily decreased with moderate wine consumption, reducing chance of death from CHD by up to 50% and other causes of death between 20% and 50% compared to abstinence. In 2000, Gronbaek and colleagues confirmed these earlier findings, explaining that wine intake may have a beneficial effect on all cause mortality that is "additive to that of alcohol."
Since 1995, Gronbaek and colleagues have published various scientific findings, indicating a reduced likelihood of hip fracture, lung cancer, upper digestive tract cancers, and certain types of stroke, ulcers, liver cirrhosis and dementia. The latter represents the most recently published 2002 study results finding some protection against dementia for wine drinkers. The researchers state, "Monthly and weekly intake of wine, ....is associated with a lower risk of dementia." (Please review the box on page 80 for a historical perspective on the key study conclusions.)
The Possible Role Of Lifestyle Factors
Related to the most recent findings from Kaiser Permanente, the Danish data also indicate that moderate consumers are more inclined to eat a healthy diet and follow favorable drinking patterns that may contribute to these positive health outcomes. In a recent article in the Feb., 2003 Journal of Cardiovascular Risk, Gronbaek writes that the issue of different effects for the beverages "is not settled yet." He further explains," The question still remains whether the differences in morbidity and mortality are caused by the drink or the drinker."
In a Feb., 2003 Scientific American article, Klatsky summarizes the data on moderation and health and explains that, "A vexing complication of all these studies, however, is that the overall habits of wine drinkers, beer drinkers and hard liquor drinkers tend to differ greatly." He explains that in Denmark, wine drinking goes hand in hand with a healthy diet, as well as with other markers such as higher socio-economic status and higher IQ. In his California studies, on the other hand, those who preferred wine also smoked less, had more education and had temperate drinking habits.
Therefore, Klatsky has long emphasized that lifestyle differences among those who prefer one type of alcoholic beverage over another make it exceedingly difficult to determine whether the differences in apparent health effects are actually related to the beverage type itself (e.g. constituents beyond alcohol), to drinking patterns (e.g. imbibe slowly and regularly with food) or to other factors (e.g. type of consumer and lifestyle habits such as exercise).
The Bottom Line Advice
These findings spearhead further scientific investigations around the world, but public health leaders call for cautious messages to the public. As many social and health issues such as binge drinking and breast cancer are still unresolved, experts and policy groups such as the American Heart Association are urging physicians to provide individualized advice.