The association between alcohol intake and sarcopenia risk Original paper

In this meta-analysis of observational studies, alcohol consumption was not associated with an increased risk of sarcopenia in male and female participants. However, in male participants, light alcohol intake was associated with a lower risk of sarcopenia.

The association between alcohol consumption and the risk of developing sarcopenia, a condition characterized by the loss of skeletal muscle mass and strength.

A total of 454,643 adults (average ages of 48–82; 57% women, 43% men).

This meta-analysis of 3 retrospective and 59 cross-sectional studies investigated the relationship between alcohol intake and sarcopenia risk, expressed as an odds ratio. The included studies used various control groups, including participants with no current alcohol use, never or former alcohol use, non-high-risk alcohol use, and lifelong abstainers.

The researchers conducted a dose-response analysis to explore the effects of varying levels of alcohol consumption on sarcopenia risk. They also completed a subgroup analysis to explore how sex, age, population, region, country, the definition of sarcopenia, and the definition of alcoholic exposure influenced the risk of developing sarcopenia.

The meta-analysis adjusted for various confounders across different studies. The adjustment for confounding factors varied by study, including factors such as age, sex, diet, comorbidities, socioeconomic status, lifestyle behaviors (e.g., smoking and physical activity), and other variables relevant to the health outcomes of sarcopenia and alcohol consumption. Notably, not all studies provided detailed information on the specific confounders using in adjustments, reflecting the diverse methodologies and analytical approaches used in the research included in the meta-analysis.

Overall, there was no association between alcohol consumption and sarcopenia risk, though the included studies showed substantial heterogeneity.

Subgroup analysis revealed a sex-specific difference: alcohol consumption was associated with a 24% lower odds of sarcopenia in men, whereas there was no association in women. This sex-specific difference was consistent across several geographical regions, including China, Asia, and North and South America.

Dose-response analysis revealed a J-shaped association between alcohol intake and sarcopenia risk in men, meaning that the risk of sarcopenia decreased up to a certain amount of alcohol intake before increasing again with higher consumption. Compared to men who didn’t drink alcohol, men who drank an average of 6 grams of alcohol per day (approx. ½ to ⅓ of a standard can of beer) had a 57% lower odds of sarcopenia. There was no dose-response relationship between alcohol intake and sarcopenia risk in women.

The association between alcohol intake and sarcopenia risk in men and women

In research on aging, the link between lifestyle choices and health outcomes, especially for sarcopenia, has become a topic of high interest. Sarcopenia is defined as the progressive loss of skeletal muscle mass, accompanied by a decrease in muscle strength and physical performance.^[1] Starting from as early as age 40, the average person experiences a linear decline in skeletal muscle mass and strength, culminating in a loss of up to 50% by the 8th decade of life.^[2] Such a significant loss of this vital, metabolically active tissue can significantly affect older adults, leading to frailty, disability, and loss of independence.^[3] Factors such as smoking, a sedentary lifestyle, and low protein intake are closely linked to the development of sarcopenia.^[1] The summarized study was designed to examine the role of alcohol consumption — a prevalent lifestyle choice — on the risk of developing sarcopenia.

Previous research that explored the association between alcohol intake and sarcopenia risk showed mixed results.^[4][5] Although a 2016 meta-analysis suggested that alcohol consumption was a protective factor for sarcopenia,^[4] a meta-analysis from 2022 found no such benefit,^[5] similar to the summarized meta-analysis, which also found that alcohol intake was not associated with sarcopenia risk overall. These inconsistent results might be explained by different studies and populations included in the meta-analyses. The 2016 meta-analysis included 13 observational studies and 13,155 participants, and the 2022 meta-analysis included 19 observational studies and 422,870 participants. In comparison, the summarized meta-analysis is the largest conducted so far, including 62 observational studies and 454,643 participants. In other words, the 2 most comprehensive meta-analyses to date, including this latest one, indicate that alcohol consumption neither benefits nor harms in the context of sarcopenia risk for the population studied as a whole. However, there was substantial heterogeneity in these findings. Hence, this general conclusion may not hold across different groups of people.

To explore the influence of different alcohol intake levels on sarcopenia risk, the summarized meta-analysis also included a dose-response analysis. The findings revealed a J-shaped dose-response curve among men, indicating that the risk of sarcopenia decreases with alcohol intake up to a certain threshold before rising again with higher consumption levels. The “optimal” amount of alcohol intake for men was identified as an intake of 6 grams daily, which was associated with a 57% lower odds of developing sarcopenia, compared to abstainers. This pattern implies that small quantities of alcohol may have beneficial effects on muscle health or related metabolic pathways, but excessive consumption eliminates these benefits.

To this point, the summarized study identified a sex-specific response to the effects of alcohol on sarcopenia risk: In men (but not women), alcohol consumption was associated with a 24% lower odds of sarcopenia, which is consistent with findings from previous research.^[5][4]

These findings indicate that alcohol’s effect on sarcopenia risk varies between men and women, probably because of biological and lifestyle factors. On the one hand, men and women metabolize alcohol differently due to body composition and hormonal differences. Men's bodies, which tend to have more muscle mass, distribute alcohol more widely, resulting in lower blood alcohol levels compared to women's bodies after the same intake. Women’s bodes generally have a higher body fat percentage and different hormonal environment (including higher estrogen and progesterone), which affect alcohol metabolism, making them more susceptible to its effects. Additionally, women tend to have lower activity levels of alcohol-metabolizing enzymes, leading to slower alcohol breakdown and longer persistence in the body. Consequently, research suggests that women are more at risk than men for alcohol-related health issues such as hangovers, liver inflammation, cardiovascular diseases, and certain cancers.^[6]

On the other hand, social and cultural patterns surrounding alcohol consumption vary significantly by sex, potentially influencing the contexts in which alcohol is consumed and its subsequent health effects. Women often drink less frequently and in smaller quantities compared to men,^[6] perhaps due to societal norms and expectations that influence drinking behaviors. Furthermore, the settings in which alcohol is consumed — ranging from social gatherings to solitary drinking — can have varying psychological and physiological effects that might interact with the aforementioned biological factors. For example, moderate drinking in social settings might confer stress-relieving benefits^[7] that contribute to its protective effects against sarcopenia in men.

Beyond these biological and social considerations, the study’s inherent limitations further complicate the interpretation of its findings. The foremost concern is the study’s focus on Asian populations (49 of the 62 analyzed studies were conducted in Asia), casting doubt on the generalizability of the results to other regions due to diverse genetic, lifestyle, diet, and cultural attitudes toward alcohol consumption. This issue is accentuated by the limited representation of Western populations, with only 3 studies involving North and South American men reporting a protective association, thereby limiting the confidence in these findings. Additionally, the absence of a universally accepted clinical definition of sarcopenia complicates the picture.^[8][9] The lack of standardized measurements for functional skeletal muscle mass and the ongoing debate within the research community about sarcopenia’s definition mean that studies often rely on varied criteria for sarcopenia, which affects the reliability of the meta-analysis and the broader research landscape.

Furthermore, it’s crucial to acknowledge that the observational nature of the evidence introduces another layer of complexity because correlation does not imply causation. This distinction is a significant limitation of the summarized study, indicating that although associations can be identified, the causal mechanisms behind these associations remain speculative. The interpretation of these findings must be approached with caution, recognizing the inherent constraints of observational studies in drawing causal inferences.

In conclusion, the summarized meta-analysis contributes valuable insights into the complex relationship between alcohol consumption and sarcopenia and highlights the possible importance of gender differences and consumption patterns. The observed sex-specific effects of alcohol on sarcopenia suggest that undetermined social and/or biological factors exist, which underscore the necessity of considering the context of alcohol consumption when evaluating its health effects. Future research should also explore the effects of different types of alcoholic beverages, ideally using a standardized clinical definition of sarcopenia.