In a recent study published in BMC Medicine, researchers discuss a 2023 study by Tian et al., which analyzed the J-shaped association between health and the consumption of alcohol, and address necessary aspects to think about when interpreting this association.

Study: The connection between alcohol consumption and health: J-shaped or less is more? Image Credit: Ievgenii Meyer / Shutterstock.com

What did the 2023 study show?

A 2023 study by a team of scientists from China led by Xia Wang used a big dataset from the National Health Interview Survey conducted between 1997 and 2014.

This data was analyzed to discover an association between light to moderate levels of alcohol consumption, in addition to cause-specific and all-cause mortality amongst the US population. From this data, the association formed a J-shaped curve, where low levels of alcohol consumption provide certain health advantages; nonetheless, after a certain threshold, health risks increase rapidly.

Light to moderate levels and infrequent consumption of alcohol were related to a reduced risk of influenza, chronic lower respiratory tract diseases, heart problems, pneumonia, and Alzheimer’s disease. Light to moderate drinking also reduced all-cause mortality and mortality related to various kidney-related diseases corresponding to diabetes mellitus and nephrosis.

Comparatively, binge drinking or high levels of alcohol consumption was related to the next risk of all-cause mortality, accident-related mortality, and cancer. Importantly, J-shaped associations have to be interpreted rigorously after considering the varied aspects related to the study methodology.

In the current study, researchers discuss the varied methodological issues to think about while interpreting this J-shaped association between alcohol consumption and disease or mortality risks.

How do lifestyle habits affect the potential advantages of drinking?

The primary factor to think about while interpreting J-shaped associations related to alcohol consumption is the definition of the reference group and problems with misclassification, which could lead on to abstainer bias and the exclusion of ex-drinkers from the reference group definition. To avoid this problem, many studies, including the one by Tian et al., used a reference group that comprised only lifetime abstainers.

Nevertheless, a recent systematic meta-analysis that included over 100 cohort studies with near half one million participants used lifetime nondrinkers because the reference group. To this end, no protective effects against all-cause mortality were related to even low levels of alcohol consumption.

While interpreting the J-shaped association between alcohol consumption and health risks, one must also consider reverse causation. Individuals who abstain from drinking might already be in poor health, while those that are lively and health conscious might drink carefully while also following other practices that provide health advantages.

Socioeconomic aspects may additionally be involved, with individuals who’re lively within the social and familial spheres of life, or have the next socioeconomic status and higher healthcare access, make healthier selections in life and drink carefully. Each of those aspects contribute independently to a lower risk of all-cause mortality.

Is any amount of alcohol healthy?

The useful effects of moderate alcohol consumption reported by Tian et al. could encourage alcohol consumption. On condition that alcohol is addictive and, amongst susceptible individuals, even low levels of alcohol intake could lead on to dependence, these results could encourage such individuals to drink, thereby resulting in drastic consequences.

The theoretical minimal exposure levels of alcohol vary across individuals of various ages and regions, thus posing the issue of defining optimal alcohol consumption levels. The useful effects of alcohol consumption may additionally vary with aspects corresponding to age, as beneficial alcohol consumption levels for younger individuals are near zero.

Moreover, the useful effects of moderate alcohol consumption, corresponding to those related to heart problems, may be outstanding only amongst populations and regions where the burden related to heart problems is high.

The protected alcohol consumption threshold just isn’t thoroughly defined, and the set standards are sometimes difficult to stick to. Moreover, the health advantages of moderate alcohol consumption could also be negated by the increased risk of esophageal and oral cancers and reduced life expectancy related to alcohol consumption.

On condition that it’s difficult to tell apart between the consequences of assorted confounding aspects and biases while determining the association between alcohol consumption and health, a Mendelian randomization approach was used to judge these correlations.

The outcomes from the Mendelian randomization and one other genetic epidemiological study reported that the role of sunshine to moderate levels of alcohol consumption in improved cardiometabolic health was either inconclusive or non-causal. Considering this, the World Health Organization (WHO) recently released an announcement that no levels of alcohol consumption could be considered protected or useful for health.

Conclusions

The present study discussed pertinent issues related to a previous study that reported a J-shaped association between light to moderate levels of alcohol consumption and health advantages.

Recent studies using genetic epidemiological and Mendelian randomization approaches to look at this association, in addition to other meta-analyses, have challenged the J-shaped association between alcohol consumption and health risks. Given the varied methodological and social issues related to this finding, the WHO continues to encourage reduced alcohol consumption.

Journal reference:

• Tsai, M. K., Gao, W., & Wen, C. P. (2023). The connection between alcohol consumption and health: J-shaped or less is more? BMC Medicine 21(228). doi:10.1186/s12916-023-02911-w