In his debut column for The World of Fine Wine, first published in Issue 75 of the print edition, Dr Erik Skovenborg sifts through the recent evidence on whether and how wine can contribute to a healthy lifestyle.
Our knowledge of the association of mortality with lifestyle factors is based largely on observational cohort studies. The word “cohort” (originally used to describe an ancient Roman military unit of between 300 and 600 men, constituting one tenth of a legion) refers to a group of people with a shared characteristic—
for example, the participants in the Nurses’ Health Study cohort were married female nurses aged 30–55 years.
At baseline, there is a collection of exposure data (such as smoking, body mass index, physical activity, alcohol intake, and diet quality) from the participants. The subjects are then followed through time (follow-up) to record when the subject develops the outcome of interest.
Let us look at the impact of healthy lifestyle factors on life expectancies in the US population.
Using data from the Nurses’ Health Study (78,865 nurses) and the Health Professionals Follow-up Study (44,354 dentists, optometrists, osteopaths, podiatrists, pharmacists,and veterinarians, between 40 and 75 years of age), Yanping Li and colleagues defined five low-risk lifestyle factors (never smoking, body mass index of 18.5–24.9kg/m2, at least 30 minutes of moderate to vigorous physical activity per day, moderate alcohol intake, and a high diet-quality score) and estimated hazard ratios for the association of total lifestyle score (0–5 scale) with mortality.1
During up to 34 years of follow-up, 42,167 deaths were documented, and Li et al estimated that the life expectancy at age 50 years for participants who adopted zero low-risk lifestyle factors was 29 years for women and 25.5 years for men. In contrast, for those who adopted all five low-risk factors, the projected life expectancy at age 50 years was 43.1 years for women and 37.6 years for men.
So, adherence to five low-risk lifestyle-related factors could prolong life expectancy at age 50 years by 14 and 12.2 years for female and male US adults, compared with individuals who adopted zero low-risk lifestyle factors.
Combinations of the healthy lifestyle factors were particularly powerful: The larger the number of low-risk lifestyle factors, the longer the potential prolonged life expectancy, regardless of the combined factors.
Using a low-risk score without moderate alcohol intake, the projected life expectancy at age 50 years was, on average, 11.4 years longer among nurses with four low-risk factors compared with those with zero low-risk factors; for men, the difference was 10 years.
The effect of a moderate alcohol intake (5–15g/day for women and 5–30g/day for men) on life expectancy was mostly due to a reduced risk of cardiovascular disease (CVD) mortality, so now you would think that a lifestyle with one or two glasses of wine with your meal would be embraced by the World Heart Federation (WHF)—an organization dedicated to the fight against CVD.
But that is not the case; on the contrary, a policy paper published by the WHF on January 20 dismisses the low-risk concept of moderate alcohol intake as a myth: “Risks due to alcohol consumption increase for all the major cardiovascular diseases, including hypertensive heart disease, cardiomyopathy, atrial fibrillation and flutter, and stroke.
“The widespread message for over 30 years from some researchers, the alcohol industry, and the media has been to promote the myth that alcohol prolongs life, chiefly by reducing the risk of CVD.”2
The policy paper continues, “The use of red wine has been promoted through various diets as a ‘heart-healthy’ beverage for the longest time. However, there are multiple reasons why the belief that alcohol is good for cardiovascular health is no longer acceptable:
1. Such evidence has been mostly based on observational studies.
2. No randomized controlled trials (RCTs) have confirmed health benefits of alcohol.
3. The presence of unaccounted confounding factors further weakens the quality of evidence.
4. Most evidence is observed only in the Caucasian population.
5. Some studies that show positive effects are funded by the alcohol industry.*”
A meta-analysis of the association of alcohol consumption with selected cardiovascular disease outcomes by Ronksley et al included 84 observational studies and found risk reductions for alcohol drinkers relative to lifetime abstainers of 13 percent for total mortality and 25 percent for coronary heart disease (CHD) mortality.3 The lowest risk occurred with 1–2 drinks (12.5–25g alcohol) a day.
Let us scrutinize the validity of the five contentions presented by WHFas “multiple reasons” to throw out the results of this mountain of evidence in favor of wine as a heart-healthy beverage.
Re 1: The evidence of the benefits of not only moderate alcohol intake but all five low-risk lifestyle factors is based on observational studies. The implication that lifestyle factors such as no tobacco, a normal weight, exercise, and a healthy diet should no longer be believed as good for cardiovascular health is hardly tenable.
Re 2: Since it is unlikely that there will ever be adequate randomized, controlled trials to judge the effect of low-risk lifestyle factors on outcomes such as myocardial infarction or cardiac death, we must use our best judgment based on carefully done observational studies, research into potential mechanisms of effect, and studies of intermediate outcomes that arein the pathways in the development of the disease.
Re 3: The presence of residual confounding factors is a weakness shared by all observational studies.To observe a CHD risk reduction of 25 percent because of an unknown confounder, if alcohol intake had no real effect, the unknown factor should, for example, increase the CHD risk twofold, and its prevalence should be 35 percent among light drinkers and 75 percent among never-drinkers. None of the risk factors studied by Poikolainen et al was a likely candidate for such an unknown confounder.4
Re 4: The meta-analysis by Ronksley et al included nine observational studies from Japan, four studies from China, and one study of Aboriginal Australians. More studies from China have been published in recent years. For example, a study of 8,469 middle-aged and older Chinese: “Participants who consumed 20–40 grams ethanol per time less than five times per week had the lowest risk of CHD”—a risk reduction of27 percent for alcohol drinkers relative to abstainers.5
Re 5: It is revealing that the WHF does not mention the fact that almost all evidence for the effect of statins (drugs that can lower your cholesterol) is funded by pharmaceutical companies. The asterisk refers to “Alcohol Issues Newsletter no.31” posted on an NGO website.6 Movendi International, the NGO quoted by WHF, has posted the following discourse analysis: “We question illogical and unfair advantages attached to alcohol use, counter-act out the alcoholization of all social events and challenge the glamorization of alcohol. We question the cultural construct of alcohol and its promoted effects and foster immunization against alcohol myths.”
Newsletter no.31 refers to a study of systematic reviews comparing reviews undertaken by authors with or without histories of alcohol-industry funding. The authors begin their article with this assertion: “Even though the overall effects of alcohol on health are overwhelmingly negative…”The conclusion of the study is vague, and you might well not expect an unprejudiced opinion in this case.
White hat bias is bias leading to the selective presentation of studies, which is considered by reviewers to be acceptable because it is in the service of worthy goals.
The worthy goal of the WHF is to reduce the burden of alcohol (for example, in 2019, 2.4 million deaths were attributed to alcohol, accounting for 4.3 percent of all deaths globally) with a Prohibition-light message: “Recent evidence has found that no level of alcohol consumption is safe for health.”
In this noble endeavor, theWHF has sacrificed the concept of moderate consumption of wine with a meal as part of a healthy lifestyle by twisting the data and cherry-picking negative studies.
The immediate consequence is the loss of one of wine’s greatest pleasures—its ability to enhance the dining experience—and a likely future consequence would be a cut of two years in your life expectancy.
“Medical authorities largely disapprove of alcohol in any form, fine wine included,” wrote Michel Bettane in his column about the dangers of alcohol.
“Hence the aggressive tactics adopted by health lobbyists, based on statistical correlations that are never really properly explained” (WFW 60, p.218). Obviously, the WHF does not have your best interest as a lover of fine wine at heart. But stay tuned to this column, where you may expect unbiased information about wine and health from a physician and fellow wine lover.
1. Li Y, Pan A, Wang DD, Liu X et al, “Impact of Healthy Lifestyle Factors on Life Expectancies in the US Population,” Circulation 138 (2018), pp.345–55.
2. “The Impact of Alcohol Consumption on Cardiovascular Health: Myths and Measures,” world-heart-federation.org/wp-content/uploads/WHF-Policy-Brief-Alcohol.pdf
3. PE Ronksley, SE Brien, BJ Turner, KJ Mukamal, WA Ghali, “Association of Alcohol Consumption with Selected Cardiovascular Disease Outcomes: A Systematic Review and Meta-Analysis,” BMJ 342 (2011), d671.
4. K Poikolainen, J Vahtera, M Virtanen, A Linna, M Kivimäki, “Alcohol and Coronary Heart Disease Risk—Is There an Unknown Confounder?” Addiction 100 (2005), pp.1150–57.
5. Zhang Y, Yu Y, Yuan Y, Yu K, Yang H, Li X et al, “Association of Drinking Pattern with Risk of Coronary Heart Disease Incidence in the Middle-Aged and Older Chinese Men: Results from the Dongfeng-Tongji Cohort. PLoS ONE 12:5 (2017), e0178070.
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