In a recent study published in the Nutrients Journal, researchers evaluated randomized controlled trials (RCTs), examining recent scientific literature on the correlations between acute and chronic red wine (RW) intake and health.
Study: Health Effects of Red Wine Consumption: A Narrative Review of an Issue That Still Deserves Debate. Image Credit: Alexander_Kuzmin/Shutterstock.com
Background
The health benefits of red wine consumption continue to be debatable. Guidelines for preventing cardiovascular diseases (CVD) and neoplasms advise against alcohol consumption; however, studies have reported that low-level intake of red wine may benefit cardiovascular health.
RW contains nutrients such as monosaccharides (such as fructose and glucose), varying levels of micronutrients (such as calcium, potassium, magnesium, copper, and iron), and a few B complex vitamins. Moreover, >100.0 polyphenols, including flavonoids, have been detected in red wine.
About the study
In the present study, researchers assessed the potential health benefits of consuming red wine. The team evaluated randomized controlled trials (RCTs) published on PubMed in English between January 1, 2000, and February 28, 2023.
The effects of consuming red wine on the following were evaluated: (i) antioxidant status; (ii) cardiovascular function; (iii) platelet function and coagulation; (iv) arterial stiffness and endothelial cell function; (v) hypertension; (vi) immunological function; (vii) lipid profiles and protein (homocysteine) levels; (viii) biological complication, glucose metabolism, and type 2 diabetes (ix) gastrointestinal activity and intestinal microbiota.
Initially, 6,429 records were identified, from which 636 duplicates were excluded. Subsequently, the remaining records (n=5,793) were screened, and the team removed studies concerning cytotoxicity, functional food items, supplementations, probiotics, sensory aspects, dysphagia, labeling and glass differences, alcohol pharmacokinetics, asthma, or nasal symptoms.
Excluded studies assessed osmotic-type stress-affected wines, wine intake biomarkers, wine extracts, drug interactions, allergens, food combinations, hypothalamic-pituitary-adrenal (HPA) axis, leptin or adiponectin, catechin, monocyte migration, and leukocyte functions.
Further, studies on natural wines, intelligence tests, diuretic effects, gastric emptying, hormones (including aromatase), and customized beverage interventions were excluded.
Moreover, conference proceedings, reviews, short surveys, abstracts, books, letters, and in vitro and animal studies were not included.
The entire text of 209 RCTs was assessed independently by two reviewers, and disagreements were resolved by another reviewer. After the full-text screening, the team excluded 118 records focusing on white wine, RW derivatives, or supplemental or nutraceutical usage. As a result, 91 RCTs were considered for the final review.
Among the included RCTs, most involved primarily type 2 diabetes patients, and seven RCTs had a >6.0-month duration (between six months and two years).
Results
Consuming red wine improved antioxidant levels, thrombotic activity, inflammatory biomarker expression, lipid levels, and intestinal microbiome, with contradictory findings for cardiac function and hypertension.
Of note, RW conferred protection against inflammation, renal damage, and oxidative stress, with a modest lowering of cardiovascular risks in most (five of seven) RCTs evaluating the effects of red wine consumption.
Moderate RW intake increased levels of enzymatic antioxidants that are involved in reducing reactive oxygen species (ROS), including superoxide dismutase-2 (SOD-2), glutathione peroxidase, and catalase (CAT), primarily due to the polyphenol content.
In addition, RW lowered the activation of inflammation-associated nuclear factor-kappa B pathways. Likewise, protein carbonyl levels and oxidized guanine species were significantly lowered among RW consumers, preventing low-density lipoprotein (LDL) oxidation.
Acute RW intake, compared to gin, had a greater down-regulatory effect on genes associated with atherosclerosis progression among males at an increased risk of CVD, likely due to the high phenolic composition.
In addition, acute RW consumption reduced vasoconstrictive peptide endothelin-1 levels. However, RW intake did not significantly affect coronary epicardial diameters or flow rate, coronary microcirculation, total carotid plaque volume, the velocity of blood flow of the middle cerebral or internal carotid artery among atherosclerosis patients.
RW can reduce platelet aggregation and coagulation by reducing prothrombin, activated factor VII, fibrinogen, and von Willebrand factor (vWF) levels and increasing plasminogen activator inhibitor-1 (PAI-1) levels.
However, polyphenols in red wine do not preserve endothelial functions. Further, RW can lower postprandial blood pressure with an increase in nitric oxide (NO) levels; however, contradictory results have been reported.
Furthermore, RW can lower serological C-reactive protein, LDL/high-density cholesterol (HDL), factor VII, and fibrinogen levels and increase those of apolipoprotein A1, tumor growth factor-beta 1 (TGF-β1), PAI, tissue plasminogen activator (tPA), and the total antioxidant capacity.
The expression of pro-inflammatory cytokines such as alpha tumor necrosis factor (TNF-α), interleukin-6 (IL-6), interferon-gamma (IFN-γ), and lipoprotein (a), reduces after RW consumption.
Moreover, RW may improve glycemic control and lower insulin levels and urinary protein levels, benefiting diabetic patients, especially those with diabetic nephropathy, with no effects on the weight of type 2 diabetic patients.
On the contrary, red wine consumption increases leptin levels, and therefore energy regulation, and improves intestinal microbial composition, along with lowering metabolic syndrome (MetS) risk factors.
RW polyphenols inhibit non-beneficial (lipopolysaccharide-producing) bacterial organisms and promote the growth of probiotic, beneficial (butyrate-producing) bacterial organisms, including Bifidobacteria, Prevotella, Enterococcus, and Bacteroides species.
Conclusion
Based on the study findings, moderate-level RW consumption confers cardiometabolic, immunological, and prebiotic health benefits, mainly due to the polyphenol content; however, further research, including long-term RCTs, is required to verify the findings and assess the safety profile of RW.
De-alcoholized-type RW (DRW) could be a good source of antioxidants to prevent oxidative damage and improve overall health. While short-term RW intake can improve the antioxidant status, lipid profile, thrombosis and inflammatory marker expression, and intestinal microbiome, longer-term RW intake could improve cardiac and renal function in type 2 diabetes patients.
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