True or False: Drinking a Glass of Red Wine a Day Can Increase Longevity
Can drinking a glass of red wine daily lead to a longer, healthier life? Some research (but not all) has shown that people who consume moderate amounts of alcohol have a decreased risk of coronary heart disease (CHD) as compared to abstainers and heavy drinkers. Studies of the French, who are famous for enjoying both red wine and low rates of CHD, first drew attention to this particular libation. Further analysis has suggested that although such trends may exist, the types of people who choose to moderately drink red wine, and possibly other alcoholic beverages, also live a healthier lifestyle in general. So is it the alcohol or some characteristic of the alcohol drinker that confers the health benefits?
Evidence for the Health Claim
According to the American Heart Association (AHA), more than 60 prospective studies have suggested that moderate alcohol consumption—defined by the Department of Health and Human Services Dietary Guidelines for Americans as having no more than one drink per day for women and no more than two drinks per day for men—may decrease the risk of CHD, ischemic heart disease and stroke, and other causes of mortality. Research shows that moderate drinkers are at less of a risk for CHD and other causes of mortality than nondrinkers, and heavy drinkers are at a much greater risk.
Some of the convincing evidence behind this claim includes:
- Researchers Klatsky and Friedman conducted a study in Northern California that followed 128,934 adults from 1978-1990 and found that people who had one or two alcoholic drinks per day had a 32% lower risk of dying from CHD than nondrinkers.
- Doll and colleagues conducted a 13-year long study examining 12,000 British doctors and their mortality in relation to their alcohol consumption. The researchers concluded that moderate drinking is associated with significantly lower mortality rates than abstaining from or over-indulging in alcohol.
- Fuchs and collaborators followed 85,709 women aged 34-59 for 12 years and found that light to moderate drinking was associated with a reduced mortality rate, but mostly benefited women who were at risk for CHD.
Why It’s Good for You
The reasons why moderate alcohol consumption is beneficial have not been well-established. There is some evidence that moderate amounts of alcohol may reduce the risk of CHD by increasing levels of high density lipoprotein (HDL), the “good” cholesterol,” and decreasing the blood’s tendency to form clots. Furthermore, studies have found an association between moderate alcohol intake and lower levels of depression, anxiety, and perceived stress. Whether the consumption of alcohol produced these effects, or visa versa, remains an open question. It is well known, however, that anxiety and depression lead to excessive alcohol consumption in certain vulnerable individuals.
What Type Is Best for You?
If moderate alcohol consumption is in fact healthy, how do we choose what drink to have? Various studies have compared the risks and benefits of drinking wine, beer, and hard liquor. In what was called the Copenhagen Heart Study, Gronbaek and colleagues followed 13,285 people ages 30-70 for 12 years starting in 1990. Results showed that low to moderate wine consumption was associated with lower risk of dying from cardiovascular and cerebrovascular disease, while similar liquor consumption actually increased risk.
In 2002, Klatsky followed up on his 1990 study with new data suggesting that regular, moderate wine drinkers had an approximately 25% lower risk of CHD than people who regularly drank the same amount of alcohol in the form of beer, and 35% lower CHD death risk than light to moderate drinkers of hard liquor. In a study comparing waist-to-hip ratios, researchers investigated one possible mechanism to explain these findings. An elevated waist-to-hip ratio is associated with an increased risk of diseases such as heart disease and diabetes. In this study of 12,145 men and women ages 45-64, beer and hard liquor drinkers had higher waist-to-hip ratios than wine drinkers.
While some researchers have found no difference between drinking red and white wine, others have found that red wines may exhibit greater benefits than other wine types. Red wine (which retains the skin of the grape) contains high levels of polyphenols, which have antioxidant properties that are believed to play a role in reducing risk of diseases such as cancer, heart disease, stroke, and Alzheimer’s disease. To what extent these antioxidants are actually involved in the protective effects of red wine is a subject of open debate.
A recent study from French researches suggest that in patients with established coronary heart disease drinking wine may increase the levels of omega-3 fatty acids, which are also known to have protective effects on heart and blood circulation.
Evidence Against the Health Claim
When analyzing the suggested benefits of moderate alcohol consumption on longevity, it is important to take into account the health effects of numerous other factors: diet, education and income level, health habits such as smoking and exercise, social engagement, and age. Many of the studies previously described found that although wine drinkers often have lower mortality rates than non-wine drinkers and abstainers, their lifestyles are also healthier overall, so it is hard to tell which factors are having the most healthful effect.
In Denmark (where the Copenhagen Heart Study took place), wine drinkers tend to consume a healthful, Mediterranean-style diet (high in fresh fruits and vegetables, fish, and olive oil, and low in meat and dairy products), and have high socioeconomic status. Klatsky’s California studies recognize that people who preferred to drink wine rather than beer or hard liquor were more highly educated, smoked less, and had more controlled drinking habits. Other studies have found that the benefits of alcohol consumption often depend on drinking patterns: Drinking slowly and with food has been shown to produce the greatest health benefits, and moderate wine drinkers reported consuming their glass or two of alcohol each day with meals.
Many proponents of wine as beneficial to health have pointed to the relatively low incidence of CHD in France, despite the typical French diet which is comparable to (or even worse than) other developed countries with high CHD rates. The French drink the most wine and have the highest level of total alcohol intake compared to 20 other industrialized countries, yet they also experience the second lowest CHD mortality rate. This phenomenon has been termed the “French Paradox”. It is important to note, however, that studies performed at the individual level have not consistently shown a positive connection between moderate wine consumption and longevity among the French. It is not clear, therefore, that a penchant for wine—red or otherwise—adequately explains the paradox.
While the evidence for the favorable health effects of moderate alcohol consumption is intriguing and deserves further study, it is unlikely that doctors will begin recommending a daily glass or two of wine to their patients anytime soon. There are at least three reasons for this.
First, since there are no randomized controlled trials on the subject (and probably never will be), it is not possible to prove a cause-and-effect relationship between alcoholic beverages and longevity. Many researchers and clinicians remain skeptical that that the alcohol itself is conferring the benefit. Patterns of drinking may simply be a marker for an unidentified attribute of the healthy drinker.
Second, the health benefits associated with moderate alcohol intake can also be obtained through safer habits such as exercise and a well-balanced diet. The antioxidant content of red wine is similar to that of fresh fruits and vegetables, and there are medications that can raise HDL levels and thin the blood more effectively than alcohol can.
Third (and most important), it is not currently possible to accurately predict who has a tendency to become an alcoholic and who does not. Recommending that all abstainers start drinking would be placing a significant number of them at unacceptable risk. For some, alcohol is an addictive drug, and alcoholism is a devastating condition that destroys lives and puts the public at risk.
The bottom line? If you don’t drink, don’t start. If you drink excessively, stop. And if you drink moderately, you may continue to raise your glass and proclaim…”to my health!”
Criqui MH, Ringel BL. Does diet or alcohol explain the French paradox?Lancet.1994;344:1719-1723.
de Jong HJ, de Goede J, Oude Griep LM, Geleijnse JM.Alcohol consumption and blood lipids in elderly coronary patients.Metabolism. 2008 Sep;57(9):1286-92.
de Lorgeril M, Salen P, Martin JL, Boucher F, de Leiris J. Interactions of wine drinking with omega-3 fatty acids in patients with coronary heart disease: a fish-like effect of moderate wine drinking. Am Heart J. 2008 Jan;155(1):175-81. Epub 2007 Sep 27
Doll R, Peto R, Hall E, et al. Mortality in relation to consumption of alcohol: 13 years' observations on male British doctors.British Med J. 1994;309:911-918.
Duncan BB, Chambless LE, Schmidt MI, et al. Association of waist-to-hip ratio is different with wine than with beer or hard liquor consumption.Am J Epidemiol. 1995;142:1034-1038.
Friedman GD, Klatsky AL. Is alcohol good for your health?New Engl. J. Med. 1993;329:1882-1883.
Gronbaek M, Deis A, Sorensen TIA, et al. Mortality associated with moderate intake of wine, beer, or spirits.British Med J.1995; 310:1165-1169.
Hennekens CH, Willett W, Rosner B, et al. Effects of beer, wine, and liquor in coronary deaths.JAMA. 1979;242: 1973-1974.
Ira J, Goldberg MD, Mosca L et al. Wine and your heart--a science advisory for healthcare professionals from the Nutrition Committee, Council on Epidemiology and Prevention, and Council on Cardiovascular Nursing of the American Heart Association.Circulation. 2001; 103:472-475.
Klatsky AL. Drink to your health?Sci Am. 2003;288(2):74-81.
Klatsky AL, Friedman GD, Armstrong MA, et al. Wine, liquor, beer, and mortality.Am J Epidemiol. 2003;158(6):585-95.
Nordøy A, Marchioli R, Arnesen H, Videbaek J. n-3 polyunsaturated fatty acids and cardiovascular diseases.Lipids. 2001;36 Suppl:S127-9.
Sacco RL, Elkind M, Boden-Albala B, et al. The protective effect of moderate alcohol consumption on ischemic stroke.JAMA.1999;281:53-60.
Urquiaga I, Leighton F. A review of the positive health effects of moderate wine consumption: from epidemiological data to biochemical understanding. Available at:http://scholar.google.com/scholar?hl=en&lr=&q=cache:rIq8Rwei2IUJ:www.bio.puc.cl/vinsalud/publica/review.doc+A+REVIEW+OF+THE+POSITIVE+HEALTH+EFFECTS+OF+MODERATE+WINE+CONSUMPTION:+FROM+EPIDEMIOLOGICAL+DATA+TO+BIOCHEMICAL+UNDERSTANDING. Accessed November 10, 2008.
Image Credit: Nucleus Communications, Inc.