If you love to drink wine you are probably concerned when you read the endless negative headlines in the newspapers about alcohol and its effect on your health. Most governments, public health organisations and even charities advise not drinking or very limited drinking of alcohol. This review aims to discuss the balance of evidence to help you decide whether alcohol and wine is good or bad for you.
Background to the debate on alcohol, wine and health
The dangers of excessive drinking and the benefits of moderate amounts of alcohol have been part of a continued debate within the health community for decades. For example, a World Health Organisation (WHO) study published in October 2015 ranked ethanol in alcoholic beverages as definitely carcinogenic in common with processed meats like salami and bacon. In January 2016, the U.K.'s Chief Medical officer (CMO), Dame Sally Davies reduced "safe" drinking guidelines to 14 units a week for both men and women. See CMO Alcohol report.
In March 2016 Stockwell et al published a new study in the Journal of Studies on Alcohol and Drugs, "Do "Moderate" Drinkers Have Reduced Mortality Risk? A Systematic Review and Meta-Analysis of Alcohol Consumption and All-Cause Mortality."
The new study was a systematic review and meta-regression analysis of studies investigating alcohol use and mortality risk after controlling for quality-related study characteristics was conducted in a population of 3,998,626 individuals, among whom 367,103 deaths were recorded. A total of 87 studies were examined and the paper concluded that when his team corrected for abstainer "biases" and certain other study-design issues, moderate drinkers no longer showed a longevity advantage stating that "Estimates of mortality risk from alcohol are significantly altered by study design and characteristics. Meta-analyses adjusting for these factors find that low-volume alcohol consumption has no net mortality benefit compared with lifetime abstention or occasional drinking."
However other academics dispute Stockwell's analysis contesting strongly his assertion that abstainers were biased because many abstainer groups include people in poor health whod cut out alcohol and that his approach to dismiss many studies because of his group's reservations about design was over zealous.
Yet, whilst drinking too much wine is certainly not good for you and even with the debate about abstainer biases and "flawed design" raised by Stockwell and other academics, some major clinical studies with many hundreds of thousands of participants give strong evidence that moderate consumption (2-3 glasses of alcohol per day) has a beneficial impact on your overall health, reduce your risk of premature death and lower your chances of having a life threatening event like a heart attack. These studies were pioneered by scientists like Sir Richard Doll, noted for being one of the first to conclusively link smoking tobacco and lung cancer.
Clinical evidence in these large scale human studies is clear that total abstainers from alcohol are likely to die younger than those drinking a glass or two a day on average of alcohol. Conversely "binge drinking" or heavy daily consumption of any alcohol is not healthy, predominantly because of negative effects on the liver and increasing the risk of cancer. A moderate approach to wine consumption is therefore to be recommended for a happier, healthier and longer life!
In addition, certain types of wine may have a more beneficial effect on health than others. Laboratory studies confirm that red wines made from grapes with thick skins (e.g. Tannat & Malbec) have higher levels of a molecule called resveratrol which appears to have positive effects on the body. However some studies show an equal positive impact for both red and white wines leading some academics to suggest that it is alcohol itself which benefits health rather than any specific compound in wine or other drinks.
Unpicking facts from fiction is a large task given the controversy and this review attempts to link the substantial human data relating to alcohol use and give a conclusion to the regular alcohol or wine drinker as to whether wine is good or bad for your health.
Gene Ford in his 2003 book "The Science of Healthy Drinking" points out that antipathy to drinking became the norm in medicine when the American Medical Association passed a resolution in June 1917 which stated "alcohol as a beverage is detrimental to the human economy...or as a stimulant or as a food has no scientific basis...the use of alcohol as a therapeutic agent should be discouraged." This was followed by Prohibition in the United States between 1920 and 1933, a nationwide constitutional ban on the sale, production, importation, and transportation of alcoholic beverages.
Prohibition may have gone but temperance is a societal normal in many countries with a pattern of government sponsored bodies omitting drink positive research in disease articles and with a tendency to overstate the risks of abuse and addiction. Many highly regarded but conservative doctors still believe in a prohibitionary agenda despite the evidence that moderate consumption has a positive impact on health outcomes. Yet most doctors themselves are not abstainers!
Many drinkers worry about addiction but the evidence is substantial in the medical literature that only a very small percentage of alcohol drinkers will become addicted. Alcohol abusers tend to have underlying psychological or social problems which is linked to the addiction and certain genetic factors are key.
Positive studies associated with alcohol are explained away by some physicians by so called "confounding factors". They will argue that those who apparently had a lower risk of heart attacks or other negative health events may have been drinking more alcohol than abstainers but focus on the potential of better lifestyle in the alcohol drinking group. Others quote the 'sick quitter' hypothesis, an argument that the risks of not drinking were magnified as some people stop consuming alcohol because of problems with their health and therefore only lifelong abstainers should be studied.
Authors like Tony Edwards in "The Good news about Booze" summarise the picture that moderate drinking - or by today's puritanical standards, even relatively heavy drinking - reduces not only heart disease risk but overall mortality risk and the relationship is causal.
Dr Kari Poikolainen, a doctor of medical science and adjunct professor in public health (since 1983) at the University of Helsinki in Finland and Research Director at the Finnish Foundation for Alcohol Studies before he retired. In 2014 he published a very good book for those interested in alcohol and health called "Perfect Drinking and its enemies".
Poikolainen says "To sum up, the most likely estimate for increased health risk (from alcohol), compared with that of abstaining, is somewhat between 90 and 150g/day. Respectively, the optimal level might be 14-22g/day" (120 ml of wine, half a large glass = 12g of 100% alcohol). Furthermore he states that "Careful participant observations have found that many alcoholics consume much more, typically between 350 to 470g/day".
Those with a negative view of the alcohol benefit talk about "Even if moderate drinking does confer health benefits, which it probably does, they are rather modest - certainly not stronger than the effect of small daily doses of aspirin on heart health...the effect may be more in line with the apparent cardio-protective benefits of eating a modest portion of nuts each day" (Time magazine 2003). Yet clinical evidence from major studies indicates that drinking moderate amounts of alcohol has a more than "modest" benefit on risk of cardiovascular disease and overall mortality and in populations who are abstainers and are already eating healthily and perhaps using measures such as Aspirin the comparative benefit of drinking 2-3 glasses of alcoholic drinks are incrementally beneficial.
In 2006 Di Castelnuovo et al used a meta analysis technique where the results of 34 studies were collated and reviewed and published in the Archives of Internal Medicine. The study looked at the link between the amount of alcohol drunk and death rates in men & women in clinical trials conducted before the end of 2005 with over 1 million subjects. Yes over 1 million people!
A J-shaped relationship between alcohol and total mortality was confirmed in both men and women. Consumption of alcohol, up to 4 drinks per day in men and 2 drinks per day in women, was inversely associated with total mortality or the chance of dying, maximum protection being 18% in women and 17% in men. Higher consumption of alcohol was detrimental. The results were consistent with studies by other research including Sir Richard Doll's 1994 study "Mortality in relation to consumption of alcohol: 13 years' observations on male British doctors".
Abigail Zuger wrote in the NYT in 2002 in the article "The case for drinking (All Together Now in Moderation), "Thirty years of research has convinced many experts of the health benefits of moderate drinking for some people. A drink or two of wine, beer or liquor is, experts say, often the single best non-prescription way to prevent heart attacks, better than a low fat diet or weight loss, better even than vigorous exercise. Moderate drinking can help prevent stokes, amputated limbs and dementia."
Zuger's view may be over eager but examples like the French Paradox (where despite a high fat diet and heavy smoking the people of several regions of France live a long life) show that moderate alcohol together with regular exercise, a good diet with olive oil/fish/nuts (in a regular, relaxed setting ideally non rushed eating) and not smoking is a key to long and healthy life.
Do we need to drink wine - no! But life without wine would be a lot duller and wine is certainly an "antidote to civilisation". What do I mean by this? Well after a stressful or boring day at work, a rough day with the children, bad or good news, human beings sometimes need a reward. In earlier generations they may have smoked a few cigarettes to wind down and now in the modern world we need something else since we now know that the TAR in cigarettes isn't exactly positive (the risks certainly outweigh the benefits). The alclohol prohibitionists may say you don't need anything, "a glass of water will do", but we know that this suggestion isn't the same and the clinical evidence is there for all to see that less than half a bottle of wine a night is a lot better for you than smoking tobacco or cannabis or eating too much as comfort food - the benefits of moderate wine drinking certainly outweigh the risks. If you can do it with exercise and healthy eating even better!
The evidence for Aspirin and Statins in reducing mortality plus risk of heart attack & stroke are substantial but given side effect concerns (e.g. gastrointestinal bleeds with Aspirin) the case for consuming 2-3 glasses of wine a day look equally compelling.
In the end it is all down to relative risk. Certain behaviours and environmental factors increase your risk of an event like cancer or heart attack. Although certain cancers such as Breast may rise in alcohol drinkers, the increase in risk is tiny compared with the absolute risk of dying in a car accident. Given the risk of dying prematurely in moderate drinkers seems convincingly lower, I for one am continuing my love of the fermented grape.
The debate and the controversy amongst academics will continue!
Negative effects of alcoholic drinks
- Alcohol: high alcohol consumption (half a bottle of wine a day and over) results in a higher blood pressure and may cause hypertension at very high levels of drinking. It has a positive correlation with mouth, throat and gullet (oesophageal) cancer and under certain circumstances with liver cancer and liver cirrhosis. Some studies suggest a positive relationship between alcohol and breast & gastric cancer, though there is evidence that it may reduce the risk of kidney cancer. The relative risk of lung cancer for men who smoke is 2,300 percent higher than it is for men who don't smoke, whereas some studies show that alcohol may have a relative risk of around 100%, i.e. doubles your chance of getting cancer, which in many cases have a small absolute lifetime risk e.g. oesophageal (1 in 112) or liver (1 in 193). The most prevalent cancers are lung (most caused by smoking), prostate and breast.
- Tannin: these compounds are plant polyphenols and may cause headaches. Tannins tend to bind starches while being digested.
- Sulfites / Sulphites: The term ‘sulfites’ is an inclusive term for sulphur dioxide (SO2). SO2 is a preservative and widely used in wine making because of its antioxidant and antibacterial properties. SO2 plays a very important role in preventing oxidisation and maintaining a wine’s freshness but some people seem to be sensitive to it and many higher quality wine makers are now trying to limit the addition of sulphite or eliminate it entirely.
Positive effects of alcoholic drinks
Risk of premature death
- Risk of dying early up to 40% lower in drinkers than abstainers, with lower benefit for women and Asians
- Moderate drinking increases longevity for all causes by about 3%
Reducing coronary heart disease
Epidemiological studies confirm that wine changes body fat levels with total cholesterol lower, bad LDL cholesterol and higher good high density lipoprotein (HDL) levels in drinkers than abstainers.
- Alcohol significantly reduces incidence of cardiovascular disease, total mortality with lower incidence of angina pain and heart attacks
- Daily alcohol intake reduces atherosclerotic plaque build up (arteriosclerosis), key in reducing the risk of strokes and heart attacks
- Nearly a 50% reduction in heart attack risk amongst moderate daily alcohol drinkers has been reported with superior benefits to using daily Aspirin
High blood pressure
- Light drinkers show favourable blood pressure profiles and less blood pressure induced strokes
- Light alcohol consumption reduces risk of stroke, whilst lifelong abstention increases risk
- Two to three alcoholic drinks per day reduce some cancer rates e.g. prostate and kidney
Alzheimer's disease and dementia
- The Polyphenols in wine have an antioxidant and free radical scavenging action which may explain their positive benefit in reducing the risks of dementia. High doses of resveratrol which is found in wine has been shown to reduce the level of amyloid beta protein in blood (where it probably accumulates in the brain causing the classic symptoms of dementia).
- Detrimental metabolic factors are reduced in diabetics who consumer moderate amount of alcohol e.g. LDL cholesterol
Colds and Flu
- Moderate daily drinking has been shown to reduce the risk of catching the common cold
Why is wine probably healthier than other alcoholic drinks?
In Arranz S 2011 "Wine, Beer, Alcohol and Polyphenols on Cardiovascular Disease and Cancer" they said that "The mechanisms responsible for the healthy effects of wine are extremely complex due to the many different pathways involved. Both alcohol and polyphenolic compounds have been extensively studied, despite the continued controversy as to which component is the most active. The underlying mechanisms to explain these protective effects against CHD include an increase in high-density lipoprotein (HDL) cholesterol, a decrease in platelet aggregation, a reduction in the levels of fibrinogen and an increase in insulin sensitivity, which have been attributed to the ethanol content in wine. Other studies have provided evidence that wine exhibits beneficial properties which are independent of the presence of alcohol, and should be attributed to their polyphenolic content.".
They conclude that "Wine consumption should not replace a healthy lifestyle. However, light-to-moderate wine drinkers, without medical complications, may be assured that their wine consumption is a healthy habit."
Cordova AC 2009 in "Polyphenols are medicine: Is it time to prescribe red wine for our patients?" states that "The habit of having one or two drinks of red wine every day with meals may translate to a longer, healthier and better quality of life."
Are certain wines better for you than others?
Red wine polyphenols are a complex mixture of flavonoids (such as anthocyanins and flavan-3-ols) and nonflavonoids (such as resveratrol, cinnamates and gallic acid). Flavan-3-ols are the most abundant, with polymeric procyanidins (condensed tannins) composing up to 50% of the total phenolic constituents. These compounds act as potent antioxidants as they reduce low-density lipoprotein (LDL) cholesterol oxidation, modulate cell signaling pathways, and reduce platelet aggregation. Red wine contains more polyphenols than white wine (around 10-fold) because during the wine making process, red wine, unlike white wine, is macerated for weeks with the skin which is one of the parts of the grape with the highest concentrations of phenolic compounds. The concentrations in red wine range from around 1.2 to 3.0 g/L.
Certain wines seem to be more healthy than others and one theory is those with the healthiest credentials have the highest amount of procyanidins (proanthocyanidins) - proC, which is a polyphenol.
The effects of proC include anti oxidant and free radical neutralisation, reducing blood fat, and inhibiting destruction of collagen, the most abundant protein in the body. They may also prevent cardiovascular disease by reducing the negative effects of high cholesterol on the blood vessels. These effects explain their apparent benefits in reducing the incidence of cardiovascular disorders.
The amount of polyphenols varies from wine to wine, country to country and grape to grape. The method of production can also significantly impact the amount of procyanidins.
In N Gall 2001 "Is wine good for your heart? A critical review" he says " Is there evidence to enable us to advise what to drink? Although the epidemiological evidence suggests not, there are at least theoretical reasons why red wines rich in flavonoids and resveratrol may hold extra benefit. Flavonoids, being found particularly in grape skins, occur in the highest concentrations in grape varieties with thick skins grown in hot climates.Cabernet sauvignon based wines from Australia, South America, and the southern Mediterranean are particularly rich sources. Syrah (shiraz) and merlot are good too. Fungal vine infection is more common in cooler, damper regions and occurs in significant quantities in pinot noir. Wines from this grape form Burgundy, Sancerre, New Zealand, and the north west United States are particularly rich in resveratrol. Merlot, gammay, syrah, zinfandel, and pinotage wines may also be too. May I advise: Nuits-St-Georges Premier Cru, Clos des Porrets, 1997, one nocte. As the French say, Salut."
What is Resveratrol and why is it important?
Other evidence points to the importance of the concentration of a stilbenoid, a type of natural phenol, called resveratrol in wine and some producers have sought to exploit higher concentrations of this chemical in their wines.
Resveratrol is found in the skin of red grapes. For example, the Malbec grape, used extensively in Argentina and the Tannat grape found in Uruguay, have thick skins and contains high levels of resveratrol. Vine grapes grown in cooler climates have higher resveratrol levels than those from warmer climates such as Australia.
However, the science behind healthy wine is controversial with some scientists arguing that polyphenols are unimportant, and that factors such as the pips used or manufacturing process are more significant.For example, see http://www.bbc.co.uk/news/health-23985540, "Red wine - what's behind its healthy reputation?"
Tannat - seemingly the grape with the highest health benefits
It is said that the tannat grape is the grape with the greatest health benefits. Tannat is used extensively in Madiran wine from SW France (not to be confused with Madeira Wine, a fortified Portuguese wine made in the Madeira Islands) and in Uruguay.
More recently wine makers in the Central Coast Region of California are beginning to grow the grape in larger quantities.
The other main factor in the health benefits of a Red Wine may be the method of duration of fermentation and maceration (which is the process of soaking crushed grapes, seeds, and stems in a wine must to extract coluor and aroma compounds as well as tannins). The long fermentation and maceration times that go into the production of Madiran Red Wine may be important factors in its apparent healthiness. The more mass produced Red Wines wines generally don’t conform to these criteria and usually have very low levels of procyanidins.
Procyanidin levels around the world (reds):
Dr. Roger Corder is an author of many scientific papers detailing his research into the flavonoids of foods, but wine in particular. He summarised his findings in "The Red Wine Diet, 2007".
Among the important observations Corder makes is that regions of the world with the greatest longevity also correspond to regions with the highest procyanidin flavonoids in their wines.
"Although differences in the amount of procyanidins in red wine clearly occur because of the grape variety and the vineyard environment, the winemaker holds the key to what ends up in the bottle. The most important aspect of the winemaking process for ensuring high procyanidins in red wines is the contact time between the liquid and the grape seeds during fermentation when the alcohol concentration reaches about 6 percent. Depending on the fermentation temperature, it may be two to three days or more before this extraction process starts. Grape skins float and seeds sink, so the number of times they are pushed down and stirred into the fermenting wine also increases extraction of procyanidins. Even so, extraction is a slow process and, after fermentation is complete, many red wines are left to macerate with their seeds and skins for days or even weeks in order to extract all the color, flavor, and tannins. Wines that have a contact time of less than seven days will have a relatively low level of procyanidins. Wines with a contact time of 10 to 14 days have decent levels, and those with contact times of three weeks or more have the highest."
He points out that deeply-coloured reds are more likely to be richer in procyanidins. Wines rich in procyanidins provide several-fold more, such that a single glass can provide the same purported health benefit as several glasses of a procyanidin-poor wine.
- Australian: on average, low levels, except Cabernet Sauvignon which is moderate.
- Argentine: Argentinian Malbec have some of the highest levels of procyanidins
- Californian: Those with the Tannat grape variety have the highest levels, but Cabernet Sauvignon has also a high content.
- Chile: Cabernet Sauvignon stands out, then only moderate in content.
- French: Bordeaux is moderate for procyanidins, Burgundy wines are low to moderate; Languedoc-Roussillon red wines moderate to high levels; Côtes du Rhône red Wines moderate to high. South-West France is a region with superior longevity of its residents. Wine of the Cahors appellation is mainly made from the Malbec grape. The wine with the highest procyanidin content is a wine grown in the Gers region of southwest France. The wines here are made with the tannat grape within the Madiran appellation; wines labeled "Madiran" must contain 40% or more tannat to be so labeled.
- Italian:The southern Italian wines from Sicily, Sardinia, and the mainland have high levels of procyanidins while most northern varieties are moderate.
- Spanish: Moderate levels
- United States: Cabernet Sauvignon is the standout for procyanidin content, with the Napa Valley a major production area.
Resveratrol concentrations in wine
Media coverage of wine health controversy
Prescription wine? - Horizon - Do I drink too much?
In this BBC documentary Dr William McCrea prescribes red wine to his patients in the Cardiac Ward of Scotland's Great Western Hospital.
The French Wine Paradox - CBS 60 Minutes
The ground breaking CBS feature on wine which changed the mindset of many an American when it comes to alcohol consumption and the impact on their health.
Eat well, Drink Wisely, Live Longer - Wine Spectator
The French Paradox
The term "French paradox" was coined by Serge Renaud, a scientist from Bordeaux University in France, and has been in use since the early 1990s. His paper was published in 1992 "Wine, alcohol, platelets, and the French paradox for coronary heart disease".
Renaud et al based on the MONItoring system for CArdiovascular disease (MONICA) project which included seven million men and women between 35 and 64 years of age from 37 European, American and Asian populations, including the US, Canada, United Kingdom, France and China, among others. The World Health Organisation followed the subjects over a period of 10 years, from the mid-1980s to the mid-1990s. France presented a markedly lower annual mortality from CAD (coronary artery disease) compared with other industrialised nations, despite the fact that cardiovascular risk factors such as cigarette smoking, blood pressure, body mass index and serum cholesterol concentration were similar among these countries; furthermore, it had a three-fold higher intake of saturated fats than that of the US and the United Kingdom, which are not well known for their healthy eating .
Renaud's observations regarding the apparent disconnect between French patterns of high saturated fat consumption and their low rates of cardiovascular disease can be quantified using data from the Food and Agriculture Organisation of the United Nations. In 2002, the average French person consumed 108 grams per day of fat from animal sources, while the average American consumed only 72 grams. The French eat four times as much butter, 60 percent more cheese and nearly three times as much pork. Although the French consume only slightly more total fat (171 g/d vs 157 g/d), they consume much more saturated fat because Americans consume a much larger proportion of fat in the form of vegetable oil, with most of that being soybean oil. However, according to data from the British Heart Foundation, in 1999, rates of death from coronary heart disease among males aged 35–74 years were 115 per 100,000 people in the U.S. but only 83 per 100,000 in France.
Possible explanations for the French Paradox:
- High per capita consumption and appreciation of wine in France, particularly red table wine - Resveratrol, Procyanidins and polyphenols
- Aspects of the French diet - The French diet is rich in vitamin K2, it is rich in short-chain saturated fatty acids and low in trans fats despite dishes like Fois Gras, Confit de Canard etc.
- Whole diet - Higher fruit and vegetable intake, more fish, Early life nutrition
- Generally don't tend to over eat and don't eat quickly - quality over quantity, portion control and lack of over consumption
- Limited processed and packaged ready meal type foods (many of which are high in sugar and salt)
- Less snacking and more moderate exercise
American Heart Association - This shows rates of death from cardiovascular diseases (heart attack and strokes combined) for men in several countries, ranked from worst to best.
France stands out as a country with a high wine consumption but with a correspondingly low level of death caused by heart attacks and strokes.
Detailed clinical evidence - the health effects of alcohol consumption
For more detailed information on the health effects of alcohol and wine consumption on health outcomes such as heart disease and death with key clinical studies please see the link below: