The ill effects of alcohol and particularly of chronic abuse are well known. Damages to the central and peripheral nervous system, the liver, the pancreas, the gastrointestinal tract, the heart, skeletal muscle and the bones are well documented in medical text books. The risks of malignancies in organs such as the stomach and breasts are also known to increase with heavy consumption. Obstetricians are quite aware of the spectrum of fetal embryopathy secondary to maternal alcohol consumption. On top of all these the death rate associated with alcohol-related car accidents has always been a major governmental concern.
Beneficial cardiovascular effects of alcohol, especially the vasodilating properties have been used in the middle ages. Hildegard Bingen, a prominent "healer" in the twelve century used a "heart wine" which consisted of wine, fresh Parsley stems, vinegar and honey to treat angina pectoris and heart failure.
In 1979, Selwyn St Leger and co-workers reported in the LANCET an ecological epidemiology study which suggested a population-based association between a reduction in deaths from heart disease and increased wine consumption. (Ref.) It was not until the early 1990s that possible positive effects of wine on mortality received a closer look. Serge Renaud and Michel de Lorgeril at INSERM in Lyon published in the LANCET in 1992 a similar study 'Wine, alcohol, platelets and the French paradox for coronary heart disease' and brought the medical community's attention to the "French" or "Mediterranean" Paradox. They used World Health Organization data to show that dairy fat consumption is highly correlated with coronary heart disease (CHD) mortality. A few French cities, however, had very high fat consumption, yet low CHD mortality rates. When they added wine consumption as a factor that affected CHD mortality, the researchers got a better correlation, with wine being a negative correlate - it appeared to reduce heart disease. In 1994, Michael Criqui and Brenda Ringel at the university of California, San Diego, subsequently investigated comparable data and reported a similar conclusion in the LANCET: Wine was one of the few dietary factors that correlated with reduced CHD mortality. (Ref.)
Subsequent to these initial reports, a large number of well-designed studies were conducted in different parts of the world and had arrived at similar conclusions, albeit contrary to some investigator's expectations.
The American Heart Association (AHA) issued a science advisory in their December 1996 issue of the journal
Circulation advising that the health benefits of alcohol are limited to one to two drinks a day. Dr. Thomas A. Pearson,
head of AHA's nutrition committee, further warns that heavy drinking can cause a variety of health problems including high blood pressure and stroke, heart muscle disorders, many kinds of cancer, liver and pancreas disease, along with accidents, homicide and suicide. He advises that people whose medical and social problems are exacerbated by drinking should abstain completely.
As an indication of the paradox of the alcohol/ health benefits issue, Dr. Pearson notes that alcohol-related diseases account for
100,000 deaths in the U.S. annually. However, if current drinkers stopped drinking, heart disease related deaths he
estimates would increase by 80,000 each year in the U.S.
Here we will look at answers to some commonly asked questions:
Representative references are directly clickable to a PubMed Medline abstract.
The answer is Yes. There are now quite conclusive evidence from many well-performed studies around the world to show that alcohol consumption in moderation lowers the population cardiovascular mortality and mortality due to stroke.
One such study was from the Harvard Medical School and was conducted over a 10.7 year period. The study included over 22,000 men in the Physicians Health Study ranging in age from 40 to 84. Results of the study revealed that men who drink moderately (two to six alcoholic drinks per week) are healthier overall than heavy drinkers (two or more drinks per day) and light drinkers (less than one drink per week). Of the 1,206 deaths, 394 were from arthrosclerotic cardiovascular causes, 488 from cancer, and 324 from other causes. It was noted that compared with light or non- rinkers, the risk of dying from all causes was 28% lower in men who drank two to four drinks per week, 21% lower in men who drank five or six drinks per week and 51% higher for men who were considered heavy drinkers. The decreased risk of death among moderate drinkers was mostly attributed to a 34% to 53% reduction in the risk of dying from cardiovascular disease. Heavy drinkers on the other hand faced a doubling of risk with respect to cancer death. (Ref.)
The mortality incidences follow a U shaped curve, goes down with increasing alcohol consumption to a point and goes up again.
The American Heart Association reported a study conducted by the Northern Manhattan Stroke Study Group in 1997 which examined alcohol consumption in the 12 months preceding a stroke in 423 patients and compared them to alcohol consumption over a 12 month period for 793 people who did not have a stroke. They found that occasional drinkers (defined as drinking less than one drink per month) had a 62% lower risk of stroke than non-drinkers. People who drank up to two drinks a day reduced their stroke risk by 45% compared to non-drinkers. However, consumption of more than five drinks a day tripled the risk of stroke. (Ref.)
The answer is: Both.
The protective effects of alcohol on coronary heart disease (CHD) are not contingent upon the kind of alcohol consumed. A protective effect of moderate intake of alcohol has been the consistent findings in many large, well-conducted studies of diverse population samples. Alcohol has been shown convincingly to raise HDL subfractions which have been found to be protective against CHD, and it may also provide protection by an antithrombotic effect. The evidence for a protective effect of moderate alcohol intake includes population studies of alcohol and CHD mortality in more than 20 countries, case-control studies, prospective cohort studies, arteriographic studies, and animal experiments. Researchers now believe that all types of alcohol not only increases HDLs but also reduce the serum levels of LDL cholesterol.
On the other hand, a sizeable number of other research reports have indicated that the antioxidants in red wine may be more protective than other types of alcohol in preventing atherosclerosis. Every glass of wine contains approximately 200 different phenolic compounds (or poly-phenols), of which several have been noted as antioxidants because they have been shown to slow the potentially damaging cell oxidation process.
In one such study conducted in Sao Paulo, Brazil in 1996 rabbits were fed a high cholesterol diet and either given red wine, red wine without the alcohol, or no wine at all. After three months, the aorta (the largest artery) was examined for fatty
plaques . Researchers found that in the rabbits not given any alcohol, 60% of their aortas were covered with fatty
plaques; this declined to 50% in the rabbits fed the non-alcoholic red wine; and to 40% in the rabbits given red wine.
All of the rabbits had 20 times the normal amounts of LDL cholesterol and total cholesterol in their blood after eating the high fat diet. Their HDL cholesterol levels were unaffected.
The authors suggested that flavonoids, present both in fruits and vegetables and red wine, "act as antioxidants and prevent the oxidation of LDL cholesterol, a step that facilitates plaque formation". The data also suggest, that in effect all forms of alcohol are equally protective.
The landmark Copenhagen City Heart Study reported in the British Medical Journal in 1995 by the Gronbaek group demonstrated significant reductions in mortality risks associated with moderate wine consumption. The positive effects were apparently not associated with other spirits or beer.
Gronbaek et al 1995
Subsequent studies in the last few years further cast light on the "wine" antioxidants.
Wine is a particularly rich dietary source of flavonoid phenolics, so many studies to uncover a cause for wine's effects have focused on its phenolic constituents, particularly resveratrol and the flavonoids.
The phenolic compounds give wine its bitterness and astringency, and are the foundation of long ageing, since they are effective antioxidants. Wines low in these substances, such as white wines, rarely age gracefully.
In 1998, the AHA reported another large Danish study which showed that wine, but not other spirits has the most protective effects against stroke.
Resveratrol
Resveratrol, which was first decribed in wine in 1992, has been studied intensely of late. The compound has been found to inhibit oxygenase enzymes and eicosanoid synthesisis which in turn inhibit platelet aggregation and reduce lipid levels in hyperlipidaemic rats. More recently, resveratrol has also been shown to inhibit the oxidation of human low density lipoproteins, which turns into atherosclerotic plagues. Studies have also shown that resveratrol, as well as some flavonoids, inhibits eicosanoid synthesis, a key step in platelet aggregation.
A well designed study from the University of California, Davis in 1996 found that mice fed with wine solids were free of malignant tumors 40% longer than sibling mice with no wine in their diets. Wine-fed mice were found to have much higher concentrations of catechin, which was known to possess antioxidant properties. Other compounds such as quercetin and trans-resveratrol have been linked with a reduction of breast cancer cells as well. In a 1996 study from the University of Virginia, researchers found that trans-resveratrol is "a very potent antagonist" to estrogen binding, "which may provide some beneficial effects in areas such as breast cancer." More recently, a study published in Science in 1997 from the University of Illinois noted that resveratrol showed "cancer chemopreventive activity," inhibiting processes that result in the forming and spreading of cancer tumors. This study found that resveratrol prevented or reduced, by up to 98%, the number of skin tumors in cancer-prone mice.
More and more studies are now emerging purporting to the chemoprotective effects of the polyphenols found in wine in the development of certain cancers. (see references below).
Just recently, resveratrol has been demonstrated to inhibit tissue factor expression in vascular cells which could be a possible mechanism for the cardiovascular benefits associated with wine consumption.
This flurry of research activity has been augmented by the more recent discovery of resveratrol's cis isomer and piceid in grapes and wine. To date at least ten different chromatographic methods have been described to
analyse wine and/or grapes for resveratrol.
Flavonoids
There are many other phenolic phytochemicals in wine that occur at a much higher concentration than resveratrol. Some of the most abundant are found at more than 100mg/l. These are mainly the flavonoids which
include four major classes: the flavonols, the anthocyanins, the catechins, and the oligomers (procyanidins) and polymers (tannins) of the catechins. The total amount of these compounds present is 1-3g/l in red wines and 0.2g/l in whites. In addition, wine contains a significant amount of non-flavonoids, including the hydroxy-cinnamates, benzoic acids, stilbenes and others, typically 0.2-0.4g/l for all wines. In many situations, but not all, these phenolic compounds are antioxidants. As the oxidation of LDL is an important step in the development of arterial plaque, and so substances that can block this oxidation should slow the disease.
Many authors now agree that the phenolic compounds in wine are responsible for the French paradox. One study measured the wine phenolics as antioxidants for LDL. The most potent were epicatechin and quercetin, while
resveratrol was less potent, and the control, alpha-tocopherol (vitamin E)
was least so.
Since the aggregation of platelets (thrombosis) is an important factor in precipitating a heart attack, compounds that reduce platelet activity could also reduce CHD mortality. Wine flavonoids have been shown to inhibit platelet aggregation. They appear to do this by specifically inhibiting oxygenase enzymes. It also seems that there are significant differences in the ability of the different flavonoids to affect platelets - quercetin is potent, while catechin is not.
The significance of these in vitro studies has recently been complemented by in vivo studies using a well developed animal thrombosis model. Cyclic flow reductions are used in animals as a model for thrombosis -
chemicals that reduce the cyclic flow reductions are thought to lower the chance of platelet aggregation and hence thrombosis. The consumption of wine or flavonoids greatly attenuated cyclic blood flow reductions. Since grape
juice also decreased the blood flow reductions (albeit with three times as much volume) it appears that non-alcoholic constituents are the active components. It is unknown whether the different potencies are the result of altered levels of phenolics or an effect of ethanol.
Type of alcoholic drink and risk of major coronary heart disease events and all-cause mortality. Am J Public Health 1999 May;89(5):685-90 Wannamethee SG, Shaper AG
Compared with other dietary sources, wine contains relatively high levels of phenolics. It is also a diverse source, as it includes significant amounts of all the major classes of phenolics. While whole fruits are rich sources, the data on juices show low levels. Apparently, normal aerobic processing degrades these compounds. Wine production, on the other hand, is largely anaerobic and thus the phenolic compounds are retained. The ethanol produced during fermentation is an effective solvent to extract the substantial amounts of flavonoid phenolics in both the skins and the seeds present in red grapes. In
white wine production the skins and seeds are separated from the juice immediately after crushing the grapes, and thus flavonoid levels are much lower. However, the phenolics present solely in the white juice, mostly the non-flavonoids, are retained in anaerobic wine production.
Here is a selection of other Medline references on the positive effects of alcohol and wine:
-- Click on the titles to view the abstracts.
Changes in postprandial lipoproteins of low and high density caused by moderate alcohol consumption with dinner Atherosclerosis 1998 Dec;141 Suppl 1:S101-3 V van Tol A, van der Gaag MS, Scheek LM, van Gent T, Hendriks HF
Resveratrol, a polyphenolic compound found in wine, inhibits tissue factor expression in vascular cells : A possible mechanism for the cardiovascular benefits associated with moderate consumption of wine Arterioscler Thromb Vasc Biol 1999 Feb;19(2):419-26 Pendurthi UR, Williams JT, Rao LV
The French paradox and wine drinking. Novartis Found Symp 1998;216:208-17; discussion 217-22, 152-8 Renaud S, Gueguen R
The effect of whisky and wine consumption on total phenol content and antioxidant capacity of plasma from healthy volunteers. Duthie GG, Pedersen MW, Gardner PT, Morrice PC, Jenkinson AM, McPhail DB, Steele GM
Rowett Research Institute, Aberdeen, Scotland, UK.
Wine consumption and ischemic heart disease mortality in Spain Med Clin (Barc) 1998 Jul 4;111(4):142-4 Garcia Colmenero C, Rodriguez Artalejo F, Vilar Alvarez F, Banegas Banegas JR, del Rey Calero J
Alcohol-free red wine enhances plasma antioxidant capacity in humans. J Nutr 1998 Jun;128(6):1003-7 Serafini M, Maiani G, Ferro-Luzzi A
Alcohol, ischemic heart disease, and the French paradox. Coron Artery Dis 1997 Oct;8(10):645-9 Constant J
Positive effects of alcohol drinking? Nord Med 1997 Dec;112(10):367-9 Gronbaek M
Alcohol, ischemic heart disease, and the French paradox. Clin Cardiol 1997 May;20(5):420-4 Constant J
The relation of alcohol intake to coronary heart disease and all-cause mortality in a beer-drinking population. Epidemiology 1997 Mar;8(2):150-6
Keil U, Chambless LE, Doring A, Filipiak B, Stieber J
Cardio-protective effect of red wine as reflected in the literature Orv Hetil 1997 Mar 16;138(11):673-8 Lugasi A, Blazovics A, Dworschk E, Feher J
Follow up study of moderate alcohol intake and mortality among middle aged men in Shanghai, China. BMJ 1997 Jan 4;314(7073):18-23
Yuan JM, Ross RK, Gao YT, Henderson BE, Yu MC
Relation between intake of flavonoids and risk for coronary heart disease in male health professionals. Ann Intern Med 1996 Sep 1;125(5):384-9 Rimm EB, Katan MB, Ascherio A, Stampfer MJ, Willett WC
Alcohol consumption and ischemic heart disease mortality in Sweden. Scand J Soc Med 1996 Jun;24(2):107-13 Messner T, Petersson B
Alcohol and coronary heart disease: the evidence for a protective effect. Clin Chim Acta 1996 Mar 15;246(1-2):59-76 Kannel WB, Ellison RC
Alcohol consumption, diet, coronary risk factors, and prevalent coronary heart disease in men and women in the Scottish heart health study. J Epidemiol Community Health 1995 Aug;49(4):354-62 Woodward M, Tunstall-Pedoe H
High-density lipoprotein cholesterol and alcohol consumption in US white and black adults: data from NHANES II. Am J Public Health 1993 Jun;83(6):811-6 Linn S, Carroll M, Johnson C, Fulwood R, Kalsbeek W, Briefel R
Effect of red wine consumption on lipoprotein (a) and other risk factors for atherosclerosis. QJM 1995 Feb;88(2):101-8 Sharpe PC, McGrath LT, McClean E, Young IS, Archbold GP
Wine and polyphenols related to platelet aggregation and atherothrombosis. Drugs Exp Clin Res 1999;25(2-3):125-31 Ruf JC
Modulation of haemostatic function and prevention of experimental thrombosis by red wine in rats: a role for increased nitric oxide production. Br J Pharmacol 1999 Jun;127(3):747-55 Wollny T, Aiello L, Di Tommaso D, Bellavia V, Rotilio D, Donati MB, de Gaetano G, Iacoviello L
Inhibition of platelet activity with red wine and grape products. Biofactors 1997;6(4):411-4 Folts JD, Begolli B, Shanmuganayagam D, Osman H, Maalej N
Red wine consumption inhibits LDL oxidation and aggregation in humans and in atherosclerotic mice. Biofactors 1997;6(4):415-9 Aviram M, Hayek T, Fuhrman B
Effects of alcohol on platelet functions. Clin Chim Acta 1996 Mar 15;246(1-2):77-89 Renaud SC, Ruf JC
Alcohol intake and the risk of lung cancer: influence of type of alcoholic
beverage Am J Epidemiol 1999 Mar 1;149(5):463-70 Prescott E, Gronbaek M, Becker U, Sorensen TI
Resveratrol, an antioxidant present in red wine, induces apoptosis in human promyelocytic leukemia (HL-60) cells. Cancer Lett 1999 Jun 1;140(1-2):1-10 Surh YJ, Hurh YJ, Kang JY, Lee E, Kong G, Lee SJ
Wine is certainly not the only dietary source of phenolic compounds. Fresh fruits are a rich source. Wine phenolics all originate from the grape, although winemaking does alter the constitution. Tea is another potent phenolic source, but green and black tea have quite different compositions. Green tea mainly contains the monomeric catechins while black tea has the oligomeric and polymeric forms.
Nutrition and alcoholic comparison of alcoholic beverages
ITEM
SERVING
CAL.
FAT
ALCOHOL
POTAS
SOD
BEER
12 oz.
BEER, LIGHT
12 oz.
GIN, DISTILLED, 90 PROOF
1 oz.
GIN AND TONIC*
1 cocktail (7.5oz.)
RUM, DISTILLED, 80 PROOF
1 oz.
VODKA, DISTILLED, 80 PROOF
1 oz.
WINE, RED
1 glass (3.5oz.)
WINE, ROSE
1 glass (3.5oz.)
WHITE, WINE
1 glass (3.5oz.)
Guidelines from the US Department of Agriculture define moderation in drinking alcohol as no more than one drink per day for women and no more than two drinks per day for men. Count as a drink:
A study from the University of Buffalo, "Drinking patterns and gender, not quantity, may determine alcohol’s effect on health," which was presented at the Congress of theToronto's Addiction Research Foundation in 1995, reported that benefits with respect to coronary heart disease and overall mortality were more pronounced when wine was consumed with meals. The study was based on results from the Risk Factor and Life Expectancy (RIFLE) Study of more than 70,000 men and women in Italy. The conclusions supported funding of a 1995 study, published in the American Journal of Clinical Nutrition, which showed that red wine consumed at lunch and dinner significantly reduced harmful LDL oxidation. Another study from the Organization for Applied Scientific Research in 1994 in the Netherlands provided evidence that consuming alcohol as part of a meal helps to reduce the risk of thrombosis. Drinking with dinner assures that the protective effects of alcohol are strongest in the evening, when fats from the dinner meal circulate through the bloodstream and carries over to the next morning when most heart attacks take place. While the researchers found this effect for all alcohol beverages, it is important to note that social science studies report that wine is consumed 80% of the time alcohol is consumed in a mealtime setting.
A recent study from the University of Pennsylvania showed that alcohol actually raises the level of free radicals, which put oxidant stress on organs such as the heart and liver, and cause them to deteriorate. The study was published in the September 99' issue of The Journal of Clinical Investigation. The authors believed that alcohol causes damage by encouraging the production of free radicals. When the body's cells are exposed to more free radicals than it can easily handle, it is in a condition called 'oxidant stress'. Further studies will be required to illucidate speculations in this area.
Here are some other recent media reports on the "newer" effects of alcohol or wine consumption :
- Wine consumption does not suppress immune system
(Ref: Study shows vino does not suppress immune system)
- Wine drinking in moderation improves memory
(Ref: Of Wine and Memory)
- Oestrogens in the grape skin may effect breast disease and impotence
(Ref: Red wine's health benefits may be due in part to "estrogen" in grape skin)
(Ref: Alcohol Consumption and Breast Cancer)
- Long term alcohol consumption reduces myocardial perfusion injuries
(ref: Researchers Discover New Way that Alcohol in Moderation May Protect the Heart
To conclude, the issue of wine and heart disease may not be entirely settled. It remains to be determined whether it is the components of wine, the amount of wine, the way wine is consumed, or the lifestyle traits of wine drinkers that are responsible for the positive effects of wine consumption on health. Nevertheless, some generalizations can be safely made:
The new label messages were suggested by two organizations that represent the wine industry. The first message, 'The proud people who made this wine encourage you to consult your family doctor about the health effects of wine consumption,' was recommended by the Coalition for Truth & Balance, which is an ad hoc group that represents 12 American wineries. The second message, 'To learn the health effects of wine consumption, send for the Federal Government's Dietary Guidelines for Americans, Center for Nutrition Policy and Promotion, USDA,' was suggested by the Wine Institute. In the guidelines, the United States Department of Agriculture (USDA) notes that 'current evidence suggests that moderate drinking is associated with a lower risk for coronary heart disease in some individuals.' ( references 1, 2)
The ATF also announced that it had launched an effort to develop legislation to strengthen its authority over alcohol labels to deter marketing to underage persons and to prevent alcohol abuse.
As of today, the new statements have not been included in wine bottle labels. Instead nearly all the American made wine has a label which says "Government Warning: (1) According to the Surgeon General women should not drink alcoholic beverages during pregnancy because of the risk of birth defects. (2) Consumption of alcoholic beverages impairs your ability to drive a car or operate machinery, and may cause Health problems".
Lending support to the positive effects of wine and alcohol on health, the US Treasury and its Bureau of Alcohol, Tobacco and Firearms (ATF) announced on 2.2.99 that it had approved two new statements for inclusion on wine labels regarding the health effects of wine.
In a statement, American Medical Association Chairman Dr. Randolph D. Smoak, Jr., noted that while the American Medical Association supports the advice to consult physicians for advice about wine consumption, 'the label alludes to the positive health effects and ignores the potential harm........ The message that should be conveyed is that while moderate wine consumption -- 1 to 2 glasses per day -- can have health benefits, all alcohol use, even at low levels, impairs driving performance and can pose significant health and safety risks' .
* Dr. Joseph SK Woo is an Obstetrician and Gynaecologist in private practice. He is a Fellow of the Hong Kong College of Obstetricians and Gynaecologists.