I wanted this blog to be about the healthy role of wine in
everyday life that I observed on my trip to Austria and Hungary last week, not the
latest salvo against alcohol from another big
study. It’s getting tiresome seeing an important issue being muddled in the
search for clarity, and I don’t like the idea that a reasonable person viewing
the same data but seeing something else might be seen as an apologist for the
alcohol industry. Yet the same mistakes endure, both in the studies themselves
and the reporting on them. They are technically correct and fundamentally wrong at the
same time.
Now to the study, invariably reported as condemning any
amount of alcohol from any source. Funded by the Bill & Melinda Gates
Foundation here in Seattle, the study updates a survey of worldwide causes of
death and “disability-adjusted life years” or DALYs.[i]
In comparing aggregated data from 1990 and 2010, an increase in the role of
alcohol was observed, so this recent report followed that trend through 2016. Tabulating
195 locations for both sexes and for 5-year age groups beginning at 15 years, the
authors looked at hundreds of data sources and studies.
It was a massive effort. In the 1990-2010 article, just the
list of contributing authors spans 4 pages, and some 194 references are cited. In that study, the authors concluded that “the contributions of risk factors to
regional and global burden of diseases and injuries has shifted substantially
between 1990 and 2010, from risk factors that mainly cause communicable
diseases in children to risk factors that mainly cause non-communicable
diseases in adults.” In 1990, the top 3 contributors were childhood
malnutrition, household air pollution from solid fuels (e.g. wood, dung, coal),
and tobacco use. By the end of the first decade of the 21st century,
the primary offenders were high blood pressure, tobacco, and alcohol.
Before I get into a critique of the study, I think it’s
important to point out what great work the Bill & Melinda Gates Foundation
does for world health issues. The types of data that studies like this one
produce are vital in order to determine how scarce resources should be
allocated. With that said, the emphasis on the apparent ascent of alcohol as a
public health concern undermines the encouraging news about progress in
prevention of childhood illnesses. Worldwide, people are living longer due to “a combination of the ageing population, substantial achievements in lowering
mortality of children aged younger than 5 years, and changes in risk factor
exposure.” The issues are morphing from
malnutrition to obesity, and from poverty to the conditions of excess consumption.
The return of the J-shaped curve
One thing that jumps out in looking at the 2016 article is
that for both men and women, the
plots for heart disease and diabetes actually show a J-shaped curve, for all
types of alcohol. It disappears only when all causes of death and disability
are lumped together. This is where the study starts to go awry, because correlation does imply
causation; for example, the study also shows a reported association of alcohol and
tuberculosis, which is an infectious disease. Counting that against a pattern
of potentially healthy wine consumption is misleading and logically questionable. Are we to
conclude that alcoholics at risk for TB
in developing countries cancel out the benefits of a glass of wine with dinner
in Europe or North America? There is a similar problem with breast cancer:
Though there is a correlation, alcohol consumption is a possible contributing factor
rather than a sole cause, and the potential benefits of red wine would be
easily obscured when the data is formatted in this way.
As with other large studies on alcohol and health, the
question of whether wine has a privileged position is often nuanced. As I noted
in my May
2018 post, habits of drinking have changed around the globe, with a shift
away from the traditional model of wine with meals. Alcohol consumption around
the globe was distinctly different in 1990, when populations with traditional
habits could be statistically isolated. This makes comparisons for wine
exceptionally challenging today. Even if it were possible to add drinking patterns (as opposed to total average
daily consumption) into an already colossal data set would have only widened
the margins of uncertainty. In the
search for granular detail with number crunching on this scale, nuggets of
wisdom aren’t easily sifted out. The complexity of the math requires that certain
things be oversimplified, and concluding that a single drink a day is risky
overstates the case.
Yet the senior author of the project, Dr. Emmanuela Gakidou
of the Institute for Health Metrics and Evaluation at the University of
Washington was quick to point out that "the health risks associated with
alcohol are massive. Our findings are consistent with other recent research,
which found clear and convincing correlations between drinking and premature
death, cancer, and cardiovascular problems. Zero alcohol consumption minimizes
the overall risk of health loss." Even if strictly true, there is no
accounting for quality of life, a known correlate of wine consumption.[ii]
When I see Dr. Gakidou dancing joyfully on a barrel, I may change my mind.
Despite the staggering number of references, there is one
missing, and from the same journal. A 1979 article in The Lancet by St. Leger, Cochrane, and Moore[iii]
found an indisputably clear inverse correlation of heart disease with wine
consumption by country, setting the foundation for what became known as the
French Paradox more than a decade later. That is where the final contradiction
lies: Even as world health improves, we move away from the healthy way of
drinking wine that sustained humanity for millennia.
[i]
Lim SS et al. A comparative risk assessment of burden of disease and injury
attributable to 67 risk factors and risk factor clusters in 21 regions,
1990–2010: a systematic analysis for the Global Burden of Disease Study 2010. Lancet.
2012 December 15; 380(9859): 2224–2260.
[ii] Alcoholic
beverage preference, 29-year mortality, and quality of life in men in old age.
Strandberg TE1, Strandberg AY, Salomaa VV, Pitkälä K, Tilvis RS, Miettinen TA.
Gerontol A Biol Sci Med Sci. 2007 Feb;62(2):213-8.
[iii] St
Leger AS, Cochrane AL, Moore F. Ischaemic heart-disease and wine. Lancet. 1979
Jun 16;1(8129):1294.
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