Wednesday, July 22, 2020

Alcohol: What is Moderation?

“Correlation does not imply causation.” Simply put, for two variables if both change, one cannot simply conclude that there is a cause-and-effect relationship between the two. Back in the late 1980s, alcohol, and more specifically, red wine, got a health claims boost from the “French Paradox,” an observation that the French, while known for consuming a butter- and cheese-containing diet high in saturated fats, had a lower than expected incidence of heart disease. This branched into two sets of putative health claims: A) That moderate consumption of alcohol was healthier than not drinking any; and B) that chemicals in red wine had a health benefit separate from the alcohol content.
For alcohol beverages, "Proof" is
2X percent. 'Hard liquor' products
tend to be 80 to 100 proof, labeled as
such, whereas wine and beer are labeled
percent alcohol content.

The observation about alcohol in any form, i.e., wine, beer, spirits, got support from what is described as a “J-shaped curve”, meaning that the relationship between alcohol and cardiovascular or all-cause mortality was not a straight line – with more drinking linked to more deaths – but rather a curved line the lowest risk at a modest alcohol intake, higher risk at zero alcohol intake, and ever-increasingly higher risk at higher and higher intakes (visually, the line resembles an aslant letter “J”). The “sweet spot” (lowest risk) looked to be around one-half to one drink per day.

Red wine contains proanthocyanidins, large molecules that contribute to the astringency of wine. Red wine also contains resveratrol, a small molecule upon which huge health claims were heaped. All sorts of health claims were made for resveratrol dietary supplements, even though the ingredient in question was being extracted from Japanese knotweed rather than grapes. Whilst positive results were demonstrated in animal models, in the end, human trials showed no benefits for lifespan, anti-cancer, anti-dementia, and so on. There was a lot of hullabaloo about resveratrol-like compounds as drugs, but that petered out. The proanthocyanidin story was latched onto by proponents of other natural sources of these compounds, leading to some positive-finding research and a lot of market hype for dark chocolate, blueberries, purple grape juice, and so on. Research on this is still a work-in-progress. Newest thinking is that while proanthocyanidins have antioxidant activity, this is not the mechanism of action.

Back to alcohol. Clearly, there are non-benign consequences of excessive drinking, defined both as a high average per week and occasions of binge drinking, the latter defined as five or more drinks for men and for or more for women. The Centers for Disease Control and Prevention (CDC) estimates that alcohol consumption accounts for approximately 100,000 deaths annually in the United States. That includes motor vehicle fatalities, drownings, suicides and homicides, liver cirrhosis and at least seven types of cancer. Excessive drinking also contributes to non-fatal negative consequences (injuries, arrests, home violence…). As to the alcohol “J-shaped curve,” it turns out that in many cultures, when compared to not drinking at all, modest amounts of alcohol consumption tends to be associated with many risk-lowering behaviors, such as less absence of obesity, more exercise, better diet and being non-users of tobacco. Non-drinkers can also have mental and physical illnesses that led them to never starting to drink in the first place, or else are non-drinkers now because of past illness. Either way, their non-drinking could contribute to the higher incidence of disease and death of non-drinkers that had nothing to do with any purported benefits of modest drinking.   

All this leads up to the fact that the Dietary Guidelines for Americans, a document that is updated every five years, is about to revise downward the definition of moderate consumption of alcohol. Below, a summary of the proposed guidelines for consumption of alcohol-containing beverages. It remains to be seen whether lobbying by the alcoholic beverages industry will lead to a restoration of the current definition of moderation – for men – as up to two drinks per day, of if this downward revision will stick. Draft wording: A) Do not begin to drink alcohol or purposefully continue to drink because you think it will make you healthier; b) If you drink alcohol, at all levels of consumption, drinking less is generally better for health than drinking more; and C) For those who drink alcohol, recommended limits are up to one drink per day for both women and men.

Different countries, different definitions of ‘moderation.’ Back in the 1950s, France recommended that people limit themselves to no more than one bottle per day. Currently no more than two drinks a day for both men and women, recently changed from three and two.

No comments:

Post a Comment