Alcohol and early mortality (before 65 years) in the 'Seguimiento Universidad de Navarra' (SUN) cohort: does any level reduce mortality?

Alcohol Drinking Impacts on Adiposity and Steatotic Liver Disease: Concurrent Effects on Metabolic Pathways and Cardiovascular Risks

PURPOSE OF REVIEW

This integrative search aimed to provide a scoping overview of the relationships between the benefits and harms of alcohol drinking with cardiovascular events as associated to body fat mass and fatty liver diseases, as well as offering critical insights for precision nutrition research and personalized medicine implementation concerning cardiovascular risk management associated to ethanol consumption.

RECENT FINDINGS

Frequent alcohol intake could contribute to a sustained rise in adiposity over time. Body fat distribution patterns (abdominal/gluteus-femoral) and intrahepatic accumulation of lipids have been linked to adverse cardiovascular clinical outcomes depending on ethanol intake. Therefore, there is a need to understand the complex interplay between alcohol consumption, adipose store distribution, metabolic dysfunction-associated steatotic liver disease (MASLD), and cardiovascular events in adult individuals. The current narrative review deals with underconsidered and apparently conflicting benefits concerning the amount of alcohol intake, ranging from abstention to moderation, and highlights the requirements for additional robust methodological studies and trials to interpret undertrained and existing controversies. The conclusion of this review emphasizes the need of newer multifaceted clinical approaches for precision medicine implementation, considering epidemiological strategies and pathophysiological mechanistic. Newer investigations and trials should be derived and performed particularly focusing both on alcohol's objective consequences as putatively mediated by fat deposition, including associated roles in fatty liver disease as well as to differentiate the impact of different levels of alcohol consumption (absence or moderation) concerning cardiovascular risks and accompanying clinical manifestations. Indeed, the threshold for the safe consumption of alcoholic drinks remains to be fully elucidated.

Effect of the Mediterranean diet in cardiovascular prevention

The Mediterranean diet is the best evidence-based model for cardiovascular prevention. In addition to 2 major randomized secondary prevention trials (Lyon Heart and CORDIOPREV) and 1 primary prevention trial (PREDIMED) that have demonstrated these benefits, there is an unprecedented body of high-quality prospective epidemiological evidence supporting these beneficial effects. The key elements of this traditional pattern are the abundant use of extra-virgin olive oil and high consumption of foods of natural plant-based origin (fruits, vegetables, nuts, and legumes) and fish, along with a reduction in processed meats, red meats, and ultraprocessed products. Moderate consumption of wine, preferably red wine, with meals is an essential element of this traditional pattern. Although removing wine consumption from the Mediterranean diet has been associated with a reduction in its preventive efficacy, doubts have recently arisen about the possible adverse effect of even low or moderate intake of any alcoholic beverages. A new large Spanish trial, UNATI, which will begin in June 2024, will randomize 10 000 drinkers aged 50 to 75 years to abstention or moderate consumption. UNATI aims to answer these doubts with the best possible evidence.

Should we remove wine from the Mediterranean diet?: a narrative review

Moderate alcohol intake (or, more specifically, red wine) represents one of the postulated beneficial components of the traditional Mediterranean diet. Many well-conducted nonrandomized studies have reported that light-to-moderate alcohol intake is not only associated with reduced risk of cardiovascular disease, but also of all-cause mortality. Nonetheless, alcohol is an addictive substance imposing huge threats for public health. Alcohol consumption is associated with increased risks of cancer, neurological harms, injuries, and other adverse outcomes. Both the Global Burden of Disease (2016) and Mendelian randomization studies recently supported that the healthiest level of alcohol intake should be 0. Therefore, despite findings of conventional observational epidemiologic studies supporting a potential beneficial role of wine in the context of a healthy Mediterranean dietary pattern, a strong controversy remains on this issue. Age, sex, and drinking patterns are likely to be strong effect modifiers. In this context, a new 4-y noninferiority pragmatic trial in Spain (University of Navarra Alumni Trialist Initiative or "UNATI"), publicly funded by the European Research Council, will randomly assign >10,000 current drinkers (males, 50-70 y; females, 55-75 y) to repeatedly receive advice on either abstention or moderation in alcohol consumption. The recruitment will begin in mid-2024. The primary endpoint is a composite of the main clinical outcomes potentially related to alcohol intake including all-cause mortality. Clinical trial registry number: PREDIMED, ISRCTN35739639, www.predimed.es; SUN, clinicaltrials.gov identifier: NCT02669602, https://medpreventiva.es/i2CmeL.

Association Between Daily Alcohol Intake and Risk of All-Cause Mortality: A Systematic Review and Meta-analyses

Importance

A previous meta-analysis of the association between alcohol use and all-cause mortality found no statistically significant reductions in mortality risk at low levels of consumption compared with lifetime nondrinkers. However, the risk estimates may have been affected by the number and quality of studies then available, especially those for women and younger cohorts.

Objective

To investigate the association between alcohol use and all-cause mortality, and how sources of bias may change results.

Data Sources

A systematic search of PubMed and Web of Science was performed to identify studies published between January 1980 and July 2021.

Study Selection

Cohort studies were identified by systematic review to facilitate comparisons of studies with and without some degree of controls for biases affecting distinctions between abstainers and drinkers. The review identified 107 studies of alcohol use and all-cause mortality published from 1980 to July 2021.

Data Extraction and Synthesis

Mixed linear regression models were used to model relative risks, first pooled for all studies and then stratified by cohort median age (<56 vs ≥56 years) and sex (male vs female). Data were analyzed from September 2021 to August 2022.

Main Outcomes and Measures

Relative risk estimates for the association between mean daily alcohol intake and all-cause mortality.

Results

There were 724 risk estimates of all-cause mortality due to alcohol intake from the 107 cohort studies (4 838 825 participants and 425 564 deaths available) for the analysis. In models adjusting for potential confounding effects of sampling variation, former drinker bias, and other prespecified study-level quality criteria, the meta-analysis of all 107 included studies found no significantly reduced risk of all-cause mortality among occasional (>0 to <1.3 g of ethanol per day; relative risk [RR], 0.96; 95% CI, 0.86-1.06; P = .41) or low-volume drinkers (1.3-24.0 g per day; RR, 0.93; P = .07) compared with lifetime nondrinkers. In the fully adjusted model, there was a nonsignificantly increased risk of all-cause mortality among drinkers who drank 25 to 44 g per day (RR, 1.05; P = .28) and significantly increased risk for drinkers who drank 45 to 64 and 65 or more grams per day (RR, 1.19 and 1.35; P < .001). There were significantly larger risks of mortality among female drinkers compared with female lifetime nondrinkers (RR, 1.22; P = .03).

Conclusions and Relevance

In this updated systematic review and meta-analysis, daily low or moderate alcohol intake was not significantly associated with all-cause mortality risk, while increased risk was evident at higher consumption levels, starting at lower levels for women than men.

Alcohol, Drinking Pattern, and Chronic Disease

This review discusses the inconsistent recommendations on alcohol consumption and its association with chronic disease, highlighting the need for an evidence-based consensus. Alcohol is an addictive substance consumed worldwide, especially in European countries. Recommendations on alcohol consumption are controversial. On one hand, many nonrandomized studies defend that moderate consumption has a beneficial cardiovascular effect or a lower risk of all-cause mortality. On the other hand, alcohol is associated with an increased risk of cancer, neurological diseases, or injuries, among others. For years, efforts have been made to answer the question regarding the safe amount of alcohol intake, but controversies remain. Observational studies advocate moderate alcohol consumption following a Mediterranean pattern (red wine with meals avoiding binge drinking) as the best option for current drinkers. However, agencies such as the IARC recommend abstention from alcohol as it is a potent carcinogen. In this context, more randomized trial with larger sample size and hard clinical endpoints should be conducted to clarify the available evidence and provide clinicians with support for their clinical practice.