Long-Term Health Outcomes of Regular, Moderate Red Wine Consumption.

Abstract

Studies that are conducted to assess alcohol's long-term health outcomes generally report the results as a pooled analysis across all types of alcohol. Questions have been raised regarding potential health differences between types of alcohol, such as beer, wine, or spirits. While these three share the same alcohol in the form of ethanol, they differ in the other compounds they contain that are particular to each type of alcohol, specifically the polyphenols in red wine. The generalizability of pooled results may be limited due to the differences in health outcomes that may exist between different types of alcohol and lead to overall conclusions that differ from the subset analysis by type of alcohol that is often reported in the data tables of an article. The objective of this systematic review was to specifically address the assessment of the long-term health outcomes of regular, moderate, red wine consumption. PubMed was searched from 1987 through June 2023. Studies were included if they met all the following criteria: adult participants, red wine consumption and its frequency (close to daily), volume in moderation (1 glass/day for women, 2 glasses/day for men), and measurement of long-term (> 2 years) health outcomes. Nonclinical animal studies, or studies with an endpoint as a marker or biomarker, without a health outcome, of short duration (< 2 years), small size (< 25 subjects), a focus on binge drinking, no wine analysis performed, review articles, meta-analysis, or editorial/commentary were excluded. A total of 74 studies met the inclusion/exclusion criteria. Of these, 27 (36%) evaluated cancer outcomes, 14 (19%) evaluated cardiovascular outcomes, 10 (14%) evaluated mortality, 7 (9%) evaluated weight gain, 5 (7%) evaluated dementia, and the remaining 11 evaluated a variety of health outcomes. There were no studies that demonstrated an association between red wine consumption and negative health outcomes. Forty-seven studies demonstrated an association between red wine consumption and positive health outcomes, whereas 26 studies were neutral, and one had mixed results where women had a positive health outcome and men were neutral. All studies on mortality and dementia showed positive health outcomes. From this systematic review of the literature, there is no evidence of an association between moderate red wine consumption and negative health outcomes. Across the various outcomes assessed, a beneficial effect of moderate red wine consumption was consistently seen for mortality and dementia, along with certain cancers (e.g., non-Hodgkin lymphoma) and cardiovascular conditions (e.g., metabolic syndrome). For other health outcomes, the association was neutral, i.e., neither harmful nor beneficial. This review is not intended to encourage red wine consumption for health outcomes but rather to avoid discouraging moderate red wine consumption based on misunderstanding or misinterpretation of the red wine data due to the reporting of pooled data across all types of alcohol.