Study Reveals That Wine Consumption Has an Inverse Relationship to Cardiovascular Mortality

In a recent study published in the Nutrients Journal, researchers aimed to understand the association between wine consumption and cardiovascular mortality, cardiovascular disease (CVD), and coronary heart disease (CHD).

The researchers performed a systematic review and meta-analysis using longitudinal studies, including cohort and case-control studies retrieved from multiple databases, which they searched from their inception to March 2023.

Study: Association between Wine Consumption with Cardiovascular Disease and Cardiovascular Mortality: A Systematic Review and Meta-Analysis. Image Credit: Alefat/Shutterstock.com

Background

Cardiovascular diseases account for a high proportion of deaths on a global scale, with CVD-related deaths surging to nearly 18 million in 2017, in which ischemic heart disease (IHD) caused almost half of the deaths. 

A previous meta-analysis suggested a J-shaped relationship between wine consumption and cardiovascular events and that moderate wine intake promoted better cardiovascular health.

A positive effect of wine on CVDs was first reported in 1979, wherein researchers also asserted that different wine components exert protective effects against pathologies, such as coronary heart diseases, CHD-associated mortality, and cancers, such as oral cancer.

Moreover, studies have suggested that de-alcoholized wines (in the absence of ethanol) are protective against thrombosis as they conserve antioxidant effects.

Light to moderate alcohol consumption positively affects general health; for instance, it acts on high-density lipoprotein cholesterol to prevent atherosclerosis, lowers the incidence of IHD, and helps with the prognosis of people at higher risk of coronary complications leading to myocardial infarction.

Excessive drinking, on the contrary, causes over 200 diseases, which makes it a leading cause of deaths globally, i.e., up to three million deaths annually. High-dose alcohol consumption also increases the risk of suicide, per psychiatrists. 

Alcohol interacts with multiple drugs, altering its metabolism or its own. Decreased alcohol metabolism could lead to increased blood alcohol levels. For example, a component in wine, resveratrol, interacts with certain drugs and modifies their metabolism.

Polyphenols of the non-flavonoid family present in red wine, like tannins, provide multiple cardiovascular health benefits. It is also anti-inflammatory, antioxidant, and antimutagenic. Nonetheless, all cardiologist agrees that light to moderate alcohol consumption has a positive effect on cardiovascular health, whereas excessive alcohol drinking elevates the risk of CHD mortality, cancers, etc. 

Mendelian randomization (MR) approaches analyzed the effects of alcohol consumption on CVDs from a genetic viewpoint and found a much-decreased risk of CHDs in carriers of the alcohol dehydrogenase 1B (ADH1B) gene when they consumed less alcohol.

Likewise, studies have shown a positive effect of wine intake on nonfatal CHD, and beer consumption poses a higher risk of a nonfatal stroke. Based on these observations, researchers have hypothesized that wine components might benefit health. 

Since studies have never stratified these effects by the type of alcohol, perhaps, the researchers assumed that all alcoholic beverages had similar beneficial effects on cardiac health. However, there is a lack of scientific evidence of which alcoholic beverages could be less harmful to CVDs.

About the study

In the present study, researchers explored the association between the incidence of CVD, cardiovascular mortality, and CHD (all cardiovascular events) and wine consumption and attempted to elucidate its nature.

First, they compared the impact of wine on participants who consumed wine against those who did not. Additionally, they analyzed whether the study design characteristics and participant traits like age and smoking affected this association.

This systematic review and meta-analysis included studies with subjects older than 18. The exposure and outcome of included studies were wine consumption and cardiovascular events, respectively. 

The team evaluated the risk of bias in cohort studies using the quality assessment tool devised by the United State’s National Heart, Lung, and Blood Institute. They used another similar tool to assess the risk of bias in the case–control studies.

Finally, two independent reviewers graded the cumulative risk of bias for each study – as good, fair, or poor; and found that the overall risk of bias for each included study was 100%. 

In the meta-analysis, they included studies with a greater sample size. They computed the relative risk (RR) and odds ratios (OR) for the correlation between wine consumption and cardiovascular events and converted hazard ratios (HR) reported in some studies to RR.

The team also calculated the pooled RRs for the effect of wine consumption on the risk of CHD, CVD, and cardiovascular mortality using DerSimonian and Lair random effect models. Finally, the team used Egger’s test to show publication bias evidence for the association between CVD and wine consumption.

Results

After an extensive search for research studies, the authors retrieved 7,042 articles from nine countries with 1,443,245 subjects and a cumulative follow-up period between four and 25 years. However, the final analytical set for this systematic review and meta-analysis comprised 25 and 22 studies, respectively. In addition, there were four case–control and 21 cohort studies.

Regarding cardiovascular events, seven, 13, and seven studies reported CVD, CHD, and cardiovascular mortality, respectively. Many studies did not report the quantity of wine consumed; thus, researchers could not determine its effect.

The current review and meta-analysis added to the previous evidence of an inverse association between the consumption of wine and three cardiovascular events evaluated in this study.

Importantly, participants’ average age, the proportion of women, the follow-up duration, or smoking status did not affect this association. Accordingly, the pooled RRs for CHD, CVD, and cardiovascular mortality were 0.76, 0.83, and 0.73, respectively, all with 95% confidence intervals (CIs). 

Though the observed inverse association applied to red and white wine, the variations in the strength of this association were attributable to the different concentrations of some components. 

Red wine has phenolic compounds, such as gallic acid, catechin, and epicatechin (flavonols), which gives it antioxidant properties. They also reduce low-density lipoprotein (LDL) oxidation, thrombosis risk, plasma, and lipid peroxide.

Also, alcoholic components of wine reduce thrombosis risk and fibrinogen levels and induce collagen and platelet aggregation. Thus, higher consumption of red wine is more beneficial for combating CVDs than other alcoholic beverages.

Conclusions

The current study results confirmed the existing data that moderate wine consumption is good for cardiac health. However, researchers should interpret these findings with caution. Increasing wine consumption could harm patients susceptible to alcohol due to age, preexisting pathologies, or medications.

Based on the findings of this review, wine could be a part of other dietary recommendations. For instance, the Mediterranean diet includes wine and recommends its use for health benefits. However, studies must assess and delineate the effect of wine drinking by the type of wine.