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The Alcohol Paradox: Balancing Health Benefits and Risks

Exploring the J-Curve Effect and Moderate Drinking Impacts

Pouring wine into a glass
Like the keto versus vegan diet debate, the health benefits of moderate consumption of alcohol are a polarized topic. The Harvard T.H. Chan School of Public Health listed moderate consumption of alcohol (one standard drink for women or one to two standard drinks for men) as one of its top five lifestyle factors for long and healthy life.1 The study highlighted the J-curve effect, where light to moderate alcohol consumption was associated with a lower risk of certain conditions, such as cardiovascular disease and diabetes, compared to both heavy drinking and complete abstinence. This pattern suggests that moderate alcohol intake can offer some protective benefits, while excessive consumption increases health risks.

 

Dan Buttner included “wine at five”2 in the list of longevity recommendations from the Blue Zones — areas with many people over 100 years old. A meta-analysis of the most beneficial components of the Mediterranean diet (emphasizing plant foods, fish, and wine) found that alcohol provided the most significant benefit of the diet, reducing premature death by 14%.3

 

Yet, among famous longevity experts, some claim any alcohol is harmful. Both Team Plantfood Dr. Greger and Team Meat Dr. Attia attest that “no dose of alcohol is healthy.”
Dr. Attia cites “healthy users” as a possible cause for the moderate drinking benefit. I am skeptical of discounting studies for healthy users. Dr. Greger references a recent meta-study that claims the apparent benefits of moderate alcohol are caused by “sick quitters,” which are people who quit alcohol because of health issues.

Conflicted Studies

A meta-study, you say? I love meta-studies for resolving this kind of disagreement. Big data usually points the way to a reliable result. However, in this case, the authors reveal bias in the abstract. A lower risk for moderate alcohol consumption with a 7% (P value) of chance is labeled nonsignificant without mention of trend, while the risk from heavier consumption is called “nonsignificantly increased,” despite having a much higher 28% (P value) chance.4

 

The study was done by the Centre for Addictions Research in BC, which understandably likely has a negative view of alcohol. Although they wanted to show that alcohol was unhealthy at any amount, even after the sick quitters were removed, moderate alcohol showed a benefit. When comparing moderate drinkers with lifetime abstainers from alcohol and removing standard confounders, the moderate drinkers had a 14% less chance of premature death. Unsatisfied with this result, they over-adjusted the results, doubling the normal number of confounders to control for a total of fifteen, including such non-standard controls as the study date and pattern of alcohol consumption.

 

Applying selective rigor to unwanted study results is an underhanded way to cast doubt on the findings. You don’t see fruit or vegetable studies controlling for the publication year of the study or pattern of fruit and vegetable consumption. Since each additional confounder control reduces the power of the study, the statistical significance of the result is reduced. That’s what the additional adjustments do in this case — moderate drinking still shows a trend for reduced premature death, but that result is no longer significant at 8%, just slightly above the 5% statistical threshold.

Where Moderate Drinking is Unhealthy

In general, a healthy lifestyle is the same in all countries. Unfortunately, this isn’t the case for alcohol. The Lancet published “Alcohol use and burden for 195 countries…” to look at the effects of alcohol globally.5 While the meta-study mentioned above focussed on developed countries, the effects of alcohol in the lowest development quintile of countries is very different. Tuberculosis is an infectious disease that usually affects the lungs. It’s the second leading infectious killer worldwide, only surpassed by COVID-19. Although it’s present in all countries, over 80% of deaths from tuberculosis are in low- and middle-income countries.6

 

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Alcohol attributable reductions in DALY by outcome.
The light blue disability years are from tuberculosis.
Unfortunately, even moderate alcohol consumption is a risk factor for tuberculosis, and this shows up strongly in the lowest quintile of countries by Social Development Index (SDI). Additionally, while some effects of alcohol show the J-curve impact, with moderate intake reducing risk, the risk for tuberculosis is a straight line of increasing risk with an increased intake of alcohol. If living in a region with high tuberculosis risk, it’s probably best to avoid even moderate alcohol consumption.

How Alcohol Helps

It was thought that the benefits of moderate red wine consumption were due to phytochemicals in the grapes, but studies across alcohol types have shown that wine doesn’t show a significant benefit over beer or spirits like vodka.7

Decreased Cardiovascular Disease

CVD shows a J-shaped curve for risk with amount of alcohol consumption
CVD shows a J-shaped curve for risk with the amount of alcohol consumption

The Lancet study above also shows the areas of benefit for alcohol. A hint is in the same Lancet breakdown. The purple negative adjustment in Disability-Adjusted Life Years (DALYs) shows the amount of ischaemic heart disease that was prevented by alcohol consumption. This proportion is most significant in the high SDI countries since there is more cardiovascular disease (CVD) in those countries. It’s also worth noting that the amount of CVD prevented becomes visible after 65 years old and steadily increases as CVD becomes more common.

Decreased Diabetes

Diabetes showing a J-shaped curve by alcohol dose
Diabetes showing a J-shaped curve by alcohol dose

Similarly, diabetes shows a J-shaped curve with alcohol consumption, with up to three standard drinks daily showing a reduced relative risk of diabetes and an increased risk after that amount. The bottom of the J-curve where diabetes risk is lowered is shorter than that for CVD, which contributes to the lower benefits when including heavier drinkers.

Social Interaction

I feel this benefit is material, yet the most difficult to quantify. “Lack of Social Interaction” doesn’t show up on death certificates. Still, alcohol is the classic social lubricant, and the effects of alcohol on mood and sociability are an essential benefit for health and longevity, even if not easy to quantify.

The Effects of Alcohol on Women

DALYs for women by cause and age from alcohol
DALYs for women by cause and age from alcohol
There is a critical difference in how alcohol affects the health of women and men. The Lancet breakdown of alcohol-attributable deaths for alcohol looks similar to that for men above. However, there is a visible net reduction in DALYs for both diabetes (pink) and ischaemic stroke (yellow), in addition to the ischaemic heart disease (purple) from CVD.  Above zero, in the increased DALYs, breast cancer (red) appears. Alcohol is linearly correlated with breast cancer in women, with one exception — women without a family history of breast cancer who ate at least 400 mcg of folate daily did not show this increased risk.8 Folate is vitamin B9 and is also crucial for women who might become pregnant to help fetal development. It’s found in dark green leafy vegetables, beans, and avocados. For women who drink alcohol and may not be getting enough folate from their diet, adding folate-fortified foods or supplementation is recommended to reduce the chance of breast cancer.

The Last Glass

Moderate daily alcohol consumption is correlated with reduced premature death by about 14%. While that’s more than the reduction from fruits (9%) or vegetables (11%), it’s about as much as eating a handful of nuts daily (15%) and less than drinking coffee (27%), high-intensity interval training (73%), or walking (75%). Given the risks of alcohol consumption, particularly for women and those in regions with high rates of tuberculosis, as well as the existence of other lifestyle factors that provide similar or greater longevity benefits, moderate alcohol consumption should be a considered and cautious choice rather than a universal recommendation. For healthy individuals who enjoy alcohol socially and in moderation, the longevity benefits appear to outweigh the risks. However, one should carefully weigh their personal risk factors, ensure adequate folate intake if female, and consider emphasizing other beneficial lifestyle habits like exercise, coffee consumption, and eating nuts. Ultimately, a long and healthy life is best achieved through a balanced approach incorporating multiple positive behaviors rather than relying on any single habit.

Footnotes

  1. Healthy lifestyle and life expectancy free of cancer, cardiovascular disease, and type 2 diabetes: prospective cohort study
  2. Longevity Link: How Wine Helps You Live Longer
  3. Mediterranean diet and its components in relation to all-cause mortality: meta-analysis
  4. Association Between Daily Alcohol Intake and Risk of All-Cause Mortality: A Systematic Review and Meta-analyses
  5. Alcohol use and burden for 195 countries and territories, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016
  6. WHO – Tuberculosis
  7. Type of alcohol consumed, changes in intake over time and mortality: the Leisure World Cohort Study
  8. Alcohol Consumption and Breast Cancer Risk in Younger Women According to Family History of Breast Cancer and Folate Intake

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