Wednesday, April 25, 2018

Alcohol consumption, mortality, and cardiovascular disease


The graphs below summarize key results from a study published in April of 2018 by the highly influential journal The Lancet (). The study reported having included at least 599,912 drinkers in the analysis and having recorded 40,310 deaths and 39,018 cardiovascular disease events. The authors of the study concluded that “For all-cause mortality, we recorded a positive and curvilinear association with the level of alcohol consumption, with the minimum mortality risk around or below 100 g per week.



The study was presented as being somewhat pessimistic: one cannot drink as much as previous data suggested. Let’s see. Two drinks of a spirit (e.g., whiskey) served “neat” (i.e., with nothing added to it) will typically add up to about 84 g; or 3 oz. If the alcohol content is 40 percent, such a double drink will contain about 33 g of alcohol. So, according to this study, you can still enjoy three double drinks of spirit per week, or six single drinks – which is almost one per day. That is not so little.

This study is consistent with most studies of the effect of alcohol consumption on health, which generally show results in terms of averages within fixed ranges of consumption. For example, they will show average mortality risks for people consuming 1, 2, 3 etc. drinks per day. These studies suggest that there is a J-curve relationship between alcohol consumption and health. That is, drinking a little is better than not drinking; and drinking a lot is worse than drinking a little.

Contrary to popular belief, the positive health effects of moderate alcohol consumption have little, if anything, to do with polyphenols such as resveratrol. Resveratrol, once believed to be the fountain of youth, is found in the skin of red grapes.

It is in fact the alcohol content that has positive effects, apparently reducing the incidence of coronary heart disease, diabetes, hypertension, congestive heart failure, stroke, dementia, Raynaud’s phenomenon, and all-cause mortality. Raynaud's phenomenon is associated with poor circulation in the extremities (e.g., toes, fingers), which in some cases can progress to gangrene.

In most studies of the effects of alcohol consumption on health, the J-curves emerge from visual inspection of the plots of averages across ranges of consumption. Rarely you find studies where nonlinear relationships are “discovered” by software tools such as WarpPLS (), with effects being adjusted accordingly.

Still, this study is indeed consistent with some past studies suggesting that the amount of alcohol intake that is optimal maybe less than most of us think ().

7 comments:

Peter said...

For people like me who have trouble reading graphs, a calculator (like a BMI calculator) of this study would be great. Put in hw many drinks a week you have, and calculate what that does for your risk of stroke, heart attack, etc.

Ned Kock said...
This comment has been removed by the author.
Ned Kock said...
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aelephant said...

How would alcohol affect you differently if you have 1 drink 6 days a week vs 3 drinks 2 days a week vs 6 drinks 1 day a week? I am thinking in terms of hormetic stress.

Ned Kock said...

Ned Kock said...
Hi Peter. The minimum mortality risk was found to be around 100 g of alcohol per week. So, according to this study, the average person can enjoy about six single drinks of alcohol per week. One drink is equivalent to approximately: one beer, one glass of wine, one shot of spirit.

Mahi Singh said...

I Really like your post.

Ned Kock said...

Hi aelephant.
The evidence that the frequency of alcohol consumptions makes a difference is rather weak, but there is some:
http://healthcorrelator.blogspot.com/2014/07/what-is-relative-risk-rr-case-of.html
In Japan there is a social belief in 'liver holidays'—abstaining from alcohol for a few days each week.
We also know that liver deaths are a result of daily or near‐daily heavy drinking, not episodic or binge drinking:
https://onlinelibrary.wiley.com/doi/full/10.1111/j.1360-0443.2008.02493.x
Not much more on frequency beyond these…