Are the Benefits of Moderate Alcohol Consumption Overblown?

In recent times, multiple studies have suggested that light to moderate alcohol consumption is beneficial for one's health, including reducing risk of cardiovascular diseases and improving memory. Dr. Michael Collins of Loyola University School of Medicine recently spoke about a June 2010 paper he was part of, regarding the possible benefits of alcohol consumption and reduced risk of dementia. Entitled Moderate Ethanol Preconditioning of Rat Brain Cultures Engenders Neuroprotection Against Dementia-Inducing Neuroinflammatory Proteins: Possible Signaling Mechanisms, he basically argues (convincingly) that sub-toxic levels of ethanol in the brain preconditions the brain against neurotoxic levels of inflammatory proteins and compounds that lead to Alzheimer's and AIDS dementia.

However, the levels of ethanol used in his study did not meet standards of moderation for human consumption. This led to speculation that the ethanol alone could not be responsible for the claims of health benefits found in humans from moderate alcohol consumption. Further research found that neuroprotection seemed to be achieved with lower non-protective ethanol levels via combinatorially preconditioning with another potentially protective agent, a constituent of wine, resveratrol. Low levels of ethanol and resveratrol alone were not sufficient enough to induce preconditioning, but combined they suppressed neural apoptosis. This is why wine is usually the alcoholic drink mentioned when discussing health benefits of light to moderate drinking.

So where does this leave us? With the U.S. alone spending billions of dollars tackling accidents, injuries, and deaths in which alcohol is involved, we seem to be inundated with new research that suggests alcohol may not be as dangerous a poison as widely believed. However, a new study published in February 2015 suggests that many of these studies are "contentious" and the positive association between alcohol use and health improvement may be a confound due to a commonly implemented statistical/methodological error. In comparing heavy drinkers versus moderate drinkers, to observe the differentiation between moderate consumption to improve health and excessive consumption to serve as a detriment to health, the researchers found that many previous studies lumped moderate drinkers and non-drinkers together, drastically skewing the data. Additionally, the 2015 study, entitled All cause mortality and the case for age specific alcohol consumption guidelines: pooled analyses of up to 10 population based cohorts, discovered a lack of older participants in the studies, a sample that could be much more negatively affected by alcohol use than younger, on-average-healthier participants that are frequently used.

Assessing 54,000 adults ages 50 and older, the study found the same set of positive attributions of moderate drinking to improving health. However, after adjusting for a range of influential factors like socioeconomic status, availability, advertising/marketing, and public policies, the researchers only found significant benefits for women 65 and older. The researchers state that the typical positive associations previously mentioned were due to "an inappropriate selection of a referent group and weak adjustment for confounders". Additionally, the study revealed a strong effect of selection biases, in which participants with poor health were excluded from the analysis. Although this is typically done to avoid misattribution of results to one cause instead of another, it exacerbates the degree of inaccuracy in reporting health benefits. For example, the beneficial effects of alcohol consumption on reducing risk of cardiovascular disease are vastly only present in those participants who were free of prevailing disease to begin with, because those with greater risks and poorer health were excluded from the beginning. This makes alcohol consumption look more beneficial that it actually is.

Medical professionals should not be advocating moderate alcohol consumption to safeguard against cardiovascular disease. Most of the research that conclusion is based on is flawed in sampling and statistical analysis. However, the effects of alcohol consumption on neurodegenerative diseases, like what Dr. Collins discussed, is an entirely different matter.

Works Cited

Collins MA, Neafsey EJ, Wang K, Achille NJ, Mitchell RM, Sivaswamy S. Moderate ethanol preconditioning of rat brain cultures engenders neuroprotection against dementia-inducing neuroinflammatory proteins: possible signaling mechanisms. Mol Neurobiol. 2010;41: 420–425.

Knott CS, Coombs N, Stamatakis E, Biddulph JP. All cause mortality and the case for age specific alcohol consumption guidelines: pooled analyses of up to 10 population based cohorts. BMJ. 2015;350:h384