Sláinte.
The Gaelic toast that accompanies the raising of glasses filled with Irish or Scotch whiskey literally means “health”.
The origin of “sláinte” dates back centuries, and so too does the connection between drinking and health. But is this connection real or just another Celtic myth like the Loch Ness monster and leprechauns?
The Dose Makes the Poison
Heavy consumers of alcohol – those who have more than 4 or 5 drinks per day – have higher rates of chronic disease and are greater risk of dying by accidental means or violence. The connection between excessive alcohol intake and early death is clear, well established, and undisputed.
By contrast, studies and news articles from across the globe have reported that people who are light or moderate drinkers of alcohol – defined as 1 or 2 drinks a day – enjoy a wide range of health benefits, from improved cardiovascular health to a slower decline in cognitive abilities with ageing.
The Weakest Link
The reputed benefits of moderate alcohol consumption are perhaps most widely known in association with a health phenomenon called the “French Paradox”.
The French Paradox attempts to address the relatively low rates of cardiovascular disease in France, where the consumption of high-fat foods is common. In the 1980s, researchers suggested that the incorporation of alcohol as part of a regular French diet could provide a cardio-protective advantage, and might explain the contradictory relationship between a high-fat diet and low rates of cardiovascular disease.
In the subsequent decades, numerous studies have identified correlations between regular, moderate alcohol consumption and a range of health benefits beyond the original cardiovascular effects that were suggested. But how strong are these links?
It turns out, they are weaker than lite beer.
The Hard Truth
Studies have found that some cardiovascular risk factors like high blood pressure and cholesterol are positively impacted by regular, low levels of alcohol consumption. But most reported health benefits associated with moderate alcohol intake are modest and achievable through other means. For example, regular exercise has a more significant impact on cholesterol levels and offers additional benefits like weight control and overall fitness.
Even the health benefits that are linked to modest levels of drinking may not be due to the alcohol at all.
By-Stander Effect
One complicating factor in interpreting studies that link alcohol consumption with health and disease are the numerous behaviours that are associated with alcohol use.
Large scale studies by the National Health and Nutrition Examination Survey (NHANES) found that greater alcohol consumption is associated with poorer quality diet, an effect that appeared in people who consumed an average of 3 or more drinks per day.
The negative effects of high alcohol intake on diet can be acute as well as chronic. A 2013 NHANES study found that alcohol consumption acutely worsened diet as drinkers tended to have poorer quality diets on days they drank than on days in which they abstained.
Interestingly, dietary habits are distinct in light drinkers as well. The Framingham Offspring Study compared alcohol consumption and dietary patterns of over 3,000 individuals in the United States between 1971 and 2008. The longitudinal study found non-drinkers and moderate drinkers had healthier dietary habits than heavy drinkers, consuming more fruits, vegetables, and grains, and less dietary fat and sugary drinks.
The tight association between drinking patterns and diet quality makes it difficult to determine how more of the health benefits come from a modest consumption of alcohol or the improved nutrition that has been reported among light drinkers across many studies.
A Placebo Effect?
Studies examining the relationship between alcohol intake and potential health benefits standardize alcohol ingestion across various types of drink. For most studies, one drink consists of 12 oz of beer, 5 oz of wine, or 1.5 oz of 80-proof spirits like whiskey, gin, or vodka.
While the amount of alcohol is generally accounted for in studies, some have suggested that not all alcoholic drinks are equal. This claim is supported by several studies that have found the health benefits of alcohol are most strongly associated with wine, in particular red wine.
Although the specific compounds responsible for any purported health benefits of red wine have yet to be definitively identified, there are several candidates.
A group of chemicals in red wine called polyphenols are anti-oxidants and may reduce the risk of cardiovascular disease, among other conditions. A well-known polyphenol in red wine is resveratrol which has been touted as a potential treatment for a number of health conditions. But this promise has yet to be consistently shown in clinical trials.
While red wine has significant amounts of healthy polyphenols, these naturally occurring antioxidants are found in a number of foods including grapes, berries, nuts, and vegetables. In fact, grapes are a better source of polyphenols than red wine, and they lack any risk associated with alcohol consumption.
Last Call
Heavy alcohol consumption has clear risks for health, both through the toxic effects of alcohol itself, and with behavioural changes like poor dietary choices.
The health benefits of light to moderate alcohol consumption are so tenuous that organizations like the American Heart Association do not recommend that non-drinkers incorporate even low levels of alcohol consumption into their diet. While some studies have reported some modest health benefits in people who regularly consume moderate amounts of alcoholic beverages, it is not clear if these benefits come from the drinks or generally healthier behaviours. Even if alcoholic drinks do offer some health benefits, the reality is many of the protective compounds can be found in even higher amounts in other foods and beverages.
None of this means that alcoholic drinks should be banished from the menu. As always, the key is moderation and balance.
Sit back, relax, and enjoy that smokey whiskey, cold beer, or elegant wine.
Sláinte mhaith.
