Polyphenols synergistically inhibit oxidative stress in subjects given red and white wine

Aim of this study was to analyse the relationship between the plasma levels of polyphenols and the antioxidant activity of red and white wine. Twenty healthy subjects (HS) were randomly allocated to drink 300 ml of red (n = 10) or white n = 10 wine for 15 days. Ten HS who refrained from any alcohol beverage for 15 days were used as control. Urinary PGF-2alpha-III, a marker of oxidative stress and plasma levels of polyphenols were measured. Urinary PGF-2alpha-III significantly fell in subjects taking wine with a higher percentage decrease in subjects given red wine (-38.5 +/- 6%, p < 0.001) than in those given white wine (-23.1 +/- 6%). Subjects taking red wine had higher plasma polyphenols than those taking white wine (1.9 +/- 0.6 microM versus 1.5 +/- 0.33 microM, p < 0.001). Plasma polyphenols were inversely correlated with urinary PGF2alpha (r = 0.77, p < 0.001). No changes of urinary isoprostanes were observed in subjects who refrained from wine intake. In vitro study demonstrated that only a mixture of polyphenols, all in a range corresponding to that found in human circulation, inhibited LDL oxidation and PKC-mediated NADPH oxidase activation. Such inhibitory effects were more marked using the concentrations of polyphenols detected in human circulation after red wine intake. This study shows that red wine is more antioxidant than white wine in virtue of its higher content of polyphenols, an effect that may be dependent upon a synergism among polyphenols.     

Concomitant consumption of red wine and polyunsaturated fatty acids in edible oil does not influence the peroxidation status of chylomicron lipids despite increasing plasma catechin concentration

Background and aimsAtherosclerosis may be ameliorated by red wine consumption possibly by providing antioxidants. The effects of red wine on the peroxidation status of chylomicrons (CM) are unknown. The aims were to compare the lipid peroxidation status of oil rich in polyunsaturated fatty acids (PUFA) from a standardised high-fat meal with that of the CM at peak concentrations following ingestion of the meal with and without wine, and to examine the contribution of wine to the antioxidant content of the plasma.Methods and resultsFasted subjects ingested the meal randomly with and without red wine. The peroxidation status was described by conjugated dienes (CD), lipid hydroperoxides (LOOH) and thiobarbituric acid reactive substances (TBARS). CM lag times and the area under the curve (AUC) of CD were determined under oxidative stress. Plasma catechin concentrations and oxygen radical absorbance capacity (ORAC) values were determined. The CM produced with and without wine did not differ in their concentration of CD, LOOH and TBARS. Lag times of CM with and without wine were not significantly different, nor were the AUC. Plasma catechin values increased significantly after consumption of wine with the meal, whereas ORAC values did not.ConclusionRed wine consumption increases plasma catechins, but does not influence lipid peroxidation in postprandial CM.     

Red or white wine assumption and serum antioxidant capacity

The biochemistry of reactive oxygen species is an important field with wide implications. Both preventive and chain breaking antioxidants have a role in the limitation of oxidative stress that accompanies aging and diseases. The potent antioxidant activity of phenolic substances of red wine, in particular, have been proposed as an explanation for the “French Paradox” (the apparent incompatibility of a high fat diet with a low incidence of coronary heart diseases). A lot of researchers emphasize beneficial effects of red wine and insist on lower or no antioxidant effect of white wine. We have been studying the effect of both white and red wine on blood antioxidant capacity in humans. The white wine we have been testing was produced by an ancient Tuscany procedure (the same used for red winemaking) which includes fermentation with grapes juice together with peelings and seeds. A statistically significant increase in total antioxidant capacity (TAC) levels was observed after 2 h from red or white wine ingestion. White wine effect appears to be faster than that of the red one, since a significant difference can also be reported after 1 h. We can conclude that the big difference in the results of serum TAC due to white wine reported by us, in comparison to those reported by others relatively to white wine produced using the French method, can be explained by the difference in the winemaking procedure we adopted.     

Red or white wine assumption and serum antioxidant capacity

The biochemistry of reactive oxygen species is an important field with wide implications. Both preventive and chain breaking antioxidants have a role in the limitation of oxidative stress that accompanies aging and diseases. The potent antioxidant activity of phenolic substances of red wine, in particular, have been proposed as an explanation for the “French Paradox” (the apparent incompatibility of a high fat diet with a low incidence of coronary heart diseases). A lot of researchers emphasize beneficial effects of red wine and insist on lower or no antioxidant effect of white wine. We have been studying the effect of both white and red wine on blood antioxidant capacity in humans. The white wine we have been testing was produced by an ancient Tuscany procedure (the same used for red winemaking) which includes fermentation with grapes juice together with peelings and seeds. A statistically significant increase in total antioxidant capacity (TAC) levels was observed after 2 h from red or white wine ingestion. White wine effect appears to be faster than that of the red one, since a significant difference can also be reported after 1 h. We can conclude that the big difference in the results of serum TAC due to white wine reported by us, in comparison to those reported by others relatively to white wine produced using the French method, can be explained by the difference in the winemaking procedure we adopted.     

Red wine and cardiovascular risks

Numerous epidemiological studies indicate that a moderate intake of alcohol is associated with a reduced risk of morbidity and mortality secondary to cardiovascular diseases. Alcohol intake from any type of alcoholic beverage appears beneficial, but red wine seems to confer additional health benefits because of the presence of red wine polyphenolic compounds (RWPC). On the basis of clinical and experimental data, the favourable effect of moderate intake of alcohol results to its action on lipid profile, hemostatic parameters, and reduction of inflammation markers. RWPC exert numerous effects including antioxidant and free radical properties, anti-aggregatory platelet and anti-thrombotic activities. Moreover, RWPC are powerful vasodilators and contribute to the preservation of the integrity of the endothelium and inhibition of smooth muscle cell proliferation and migration. All these effects of red wine might interfere with atherosclerotic plaque development and stability, vascular thrombosis and occlusion. Although, red wine might be of therapeutic benefit in cardiovascular diseases, prospective controlled clinical studies are still lacking.     

Acute effects of a high-fat meal with and without red wine on endothelial function in healthy subjects.

It has been suggested that a high-fat meal may acutely impair endothelium-dependent vasodilation and that this impairment may be prevented by concomitant intake of antioxidants. Because red wine contains antioxidant polyphenols and may reduce cardiovascular disease, we examined the effect of red wine on postprandial endothelial function. Using a crossover design, 13 healthy volunteers consumed a high-fat meal (0.8 g fat/kg body weight) with red wine (3 ml/kg) or an isocaloric control beverage on 2 separate days, 1 week apart. Flow-mediated dilation of the brachial artery was examined by vascular ultrasound at baseline and at 2, 4, and 6 hours after the meal. At these times, flow-mediated dilation with the high-fat meal and control beverage was 9.5 +/- 5.0%, 7.9 +/- 5.1%, 6.8 +/- 3.6%, and 7.3 +/- 4.6%, respectively (nonsignificant trend). There was also a nonsignificant trend for flow-mediated dilation after the high-fat meal with wine: 8.0 +/- 4.1%, 5.7 +/- 4.7%, 6.4 +/- 3.1%, and 6.9 +/- 3.8%, respectively. There was no difference in the effects between wine and the control beverage (p = 0.77). Triglycerides increased 2- to 2.7-fold over baseline (p = 0.0001) with a peak occurring 5 hours after the high-fat meals. In contrast to previous studies, the present study did not demonstrate a significant effect of a high-fat meal on endothelial vasomotor function in healthy subjects. Under these conditions, we did not demonstrate a beneficial acute effect of red wine on endothelial function.     

Erythrocyte plasma membrane redox system in human aging

Eukaryotic cells display a plasma membrane redox system (PMRS) that transfers electrons from intracellular substrates to extracellular electron acceptors. The physiologic importance of PMRS is still not fully understood. The authors have carried out studies to determine the activity of PMRS in human erythrocytes as a function of age and correlate the activity with total plasma antioxidant capacity in an effort to understand the role of PMRS in human aging. The study was carried out on 80 normal healthy subjects of both genders between the ages of 18 and 85 years. The activity of erythrocyte PMRS was estimated by following the reduction of ferricyanide. The total antioxidant capacity of the plasma was estimated in terms of Ferric Reducing Ability of Plasma (FRAP) values. A significant (p < 0.0001) positive correlation (r = 0.7797) is observed between PMRS activity of erythrocytes and human age. There is an age-dependent decrease in total plasma antioxidant capacity measured in terms of FRAP values. A highly significant correlation is observed between PMRS activity and plasma FRAP values. The authors hypothesize that the increased PMRS in erythrocytes during aging may be a protective mechanism of the system for efficient extracellular DHA reduction and ascorbate recycling under condition of increased oxidative stress.     

Wine and oxidative stress: Up-to-date evidence of the effects of moderate wine consumption on oxidative damage in humans

Wine and alcohol consumption has been considered to be protective against coronary heart disease development, an oxidative stress associated disease. Wine contains polyphenols displaying antioxidant properties tested in in vitro and in vivo studies. Due to this, a general consensus exists, both among the general public and the scientific community, that wine, particularly red wine, is an antioxidant beverage. Alcohol consumption, however, is associated with oxidative damage. Several studies have been carried out on the antioxidant health benefits of wine and wine polyphenols. However, adequate scientific evidence (Level I or II) is required to be provided before recommendations or statements which can reach the general public can be formulated. Here, we summarize the state of the art of the up-to-date body of knowledge, and the extent to which there exists evidence of the benefits of moderate wine consumption on oxidative damage in humans. From the available data, there is no evidence, at present, that sustained wine consumption provides antioxidant benefits in healthy volunteers other than to counteract a possible pro-oxidative effect of the alcohol. On the contrary, data on the antioxidant protective effect of red wine in oxidative stress situations are promising. In this way, the postprandial oxidative stress after a meal, despite the diversity of biomarkers used for its evaluation, is counteracted by the ingestion of wine. Further studies are warranted.     

A daily glass of red wine induces a prolonged reduction in plasma viscosity: a randomized controlled trial.

Moderate red wine consumption has been associated with decreased risk of coronary heart disease. Reduced plasma viscosity and fibrinogen levels have been launched as possible contributors to this risk reduction. The effect of moderate red wine consumption on plasma viscosity, however, has not been investigated in a prospective, randomized trial. We wanted to evaluate the effect of moderate red wine consumption on plasma viscosity, fibrinogen concentration and fibrinogen subfractions. Healthy, nonsmoking volunteers were assigned to consume one glass of red wine daily for 3 weeks in a prospective, randomized cross-over study. In the second 3-week period the volunteers abstained from alcohol use. The plasma viscosity, fibrinogen concentration and the distribution of the main fibrinogen subfractions were determined at inclusion, after wine drinking and after abstention. Plasma viscosity was reduced by 0.026 and 0.024 mPa.s in the two groups following wine intake (95% confidence interval, 0.009-0.043, P = 0.004; 95% confidence interval, 0.0083-0.039, P = 0.003). The decrease in plasma viscosity was maintained following 3 weeks of abstention. The fibrinogen concentration was reduced by 0.17 g/l following wine drinking in the group starting with abstention (95% confidence interval, 0.04-0.29, P = 0.01). The distribution of the fibrinogen subfractions remained unaltered. We conclude that a daily glass of red wine for 3 weeks significantly reduces plasma viscosity. Fibrinogen concentrations are also significantly reduced, when preceded by an abstention period. The decreased viscosity levels are maintained after 3 weeks of abstention, suggesting a sustained viscosity lowering effect of red wine.     

Red wine, dealcoholized red wine, and especially grape juice, inhibit atherosclerosis in a hamster model

The French have low coronary heart disease mortality with high fat consumption; this epidemiological anomaly is known as the "French Paradox" and is commonly attributed to the consumption of red wine. However, epidemiology studies have not convincingly shown a superiority of red wine vs. alcohol or other alcoholic beverages. We have used the hamster model of atherosclerosis to determine the active ingredient(s) of red wine responsible for the beneficial effect. Hamsters (nine in each group) were given a cholesterol/saturated fat for 10 weeks to induce foam cell formation. Water or 6.75% ethanol was given to the control groups. Beverages tested included red wine, dealcoholized red wine, and red grape juice, all diluted in half. Ethanol and all beverages caused a significant reduction in atherosclerosis. The combination of ethanol in red wine had the largest effect in decreasing atherosclerosis by both hypolipemic and antioxidant mechanisms. When compared with dealcoholized wine and normalized to polyphenol dose, red wine's beneficial effects can be attributed entirely to the polyphenols. Grape juice had a significant benefit at a much lower dose of polyphenols than the wines. Grape juice was calculated to be much more effective than red wine or dealcoholized red wine at the same polyphenol dose in inhibiting atherosclerosis and improving lipids and antioxidant parameters. This data suggests that polyphenolic beverages from grapes are beneficial in inhibiting atherosclerosis by several mechanisms. Grape juice or non-alcoholic red wine are an excellent alternative to red wine in this model of atherosclerosis.     

Red wine and red wine polyphenolic compounds but not alcohol inhibit ADP-induced platelet aggregation

Background: Moderate alcohol consumption reduces the risk of cardiovascular diseases, especially coronary heart disease (CHD). Because of the presence of polyphenols in red wine, this type of beverage may be superior to other alcoholic drinks in the prevention of CHD. Inhibition of platelet aggregation is thought to be one of the mechanisms underlying this favorable effect. The present study analyzes the direct effect of alcohol and red wine polyphenols on platelet aggregation. Methods: Unfractionated red wine, a red wine polyphenolic extract, and alcohol were added in different concentrations to a standardized quantity of blood platelets 2 min before aggregation was induced by different concentrations of ADP. Aggregation was measured in an aggregometer and results were compared to a control 0.9% NaCl solution. Results: Alcohol in concentrations up to 0.24 percent did not inhibit platelet aggregation in vitro initiated with ADP The polyphenolic red wine extract inhibited aggregation dose-dependently and significantly from concentrations of 45 mg/l ( [Formula: see text] ) or more. Red wine only inhibited platelet aggregation at very high concentrations ( approximately 0.24 and 0.48 alcohol%). Conclusions: Consumption of red wine has an inhibitory effect on platelet aggregation, which is caused by the polyphenolic compounds in the wine. Alcohol itself does not have a direct inhibitory effect within a range up to 0.24 percent. Since this effect is only observed at very high concentrations, it is unlikely to be of clinical relevance in a moderate drinking pattern. The results do not exclude platelet inhibition by wine in vivo. However, this must be related to metabolic changes rather than to direct blockade.     

Endogenous urate production augments plasma antioxidant capacity in healthy lowland subjects exposed to high altitude

BACKGROUND: Both tissue hypoxia in vitro, and whole-body hypoxia in vivo, have been found to promote the release of reactive oxygen species (ROS) that are potentially damaging to the cardiovascular system. Antioxidant systems protect against oxidative damage by ROS and may exhibit some degree of responsiveness to oxidative stimuli. Production of urate, a potent soluble antioxidant, is increased in hypoxic conditions. We aimed to determine whether urate is an important antioxidant defense in healthy subjects exposed to hypoxia. METHODS: We conducted a cohort study of 25 healthy lowland volunteers during acute exposure to high altitude (4 days at 3,600 m, followed by 10 days at 5,200 m) on the Apex high-altitude research expedition to Bolivia. We measured markers of oxidative stress (8-isoprostane F2), serum urate concentration, and total plasma antioxidant activity by two techniques: 2,2'-amino-di-[3-ethylbenzthiazole sulfonate] spectrophotometry (total antioxidant status [TAS]) and enhanced chemiluminescence (ECL). RESULTS: On ascent, F2-isoprostane levels were significantly elevated compared with those at sea level (p < 0.01). After 1 week at high altitude, plasma antioxidant capacity (AOC) by both TAS and ECL, and serum urate concentration were significantly elevated (each p < 0.01 vs sea level), and F2-isoprostane levels were reduced to values at sea level. There was a highly significant correlation between plasma urate and AOC at this stage (ECL, r(2) = 0.59, p = 0.0001; TAS, r(2) = 0.30, p = 0.0062). CONCLUSIONS: Our results support the hypothesis that urate may act as a responsive endogenous antioxidant in high-altitude hypoxia.     

Constituents of red wine other than alcohol improve endothelial function in patients with coronary artery disease

BACKGROUND: Several studies suggest that red wine is beneficial in coronary artery disease (CAD). Although the long-term effect of moderate red wine consumption on endothelial function is currently under investigation, there is little knowledge about its effect on postprandial endothelial function and haemostatic factors. The aim of the present study was to investigate the postprandial effects of alcohol content and the antioxidants of red wine on endothelial function and fibrinogen levels in CAD patients. METHODS: Fifteen males with angiographically documented CAD were recruited for the study. All volunteers ingested 250 ml of either red wine or de-alcoholized red wine on two different days. Blood samples (for analysis of fibrinogen and blood lipids) were collected and flow-mediated dilatation (FMD) was determined before and 30, 60 and 90 min following consumption of each beverage RESULTS: FMD was higher following the consumption of de-alcoholized red wine [type of wine effect, P=0.05 repeated measures analysis of variance (ANOVA)]. Furthermore, the pattern of the response was different between the two beverages, as FMD increased following the ingestion of de-alcoholized red wine, but it decreased after consumption of regular red wine (type of wine by time interaction effect, P=0.006 repeated measures ANOVA). Fibrinogen concentrations were unaltered CONCLUSIONS: Acute ingestion of red wine without alcohol led to higher FMD than ingestion of regular red wine in CAD patients. The acute effect of red wine on endothelial function may be different than its long-term effect and it could be attributed to its constituents other than alcohol.     

Experimental evidence for the cardioprotective effects of red wine

Both epidemiological and experimental studies have revealed that intake of wine, particularly red wine, in moderation protects cardiovascular health; however, the experimental basis for such an action is not fully understood. Because all types of red wine contain varying amounts of alcohol and antioxidants, it is likely that the cardioprotective effect of red wine is due to both these constituents. In view of its direct action on the vascular smooth muscle cells, alcohol may produce coronary vasodilation in addition to attenuating oxidative stress by its action on the central nervous system. The antioxidant components of red wine may provide cardioprotection by their ability to reduce oxidative stress in the heart under different pathological conditions. Mild-to-moderate red wine consumption improves cardiac function in the ischemic myocardium through the protection of endothelial function, the expression of several cardioprotective oxidative stress-inducible proteins, as well as the activation of adenosine receptors and nitrous oxide synthase mechanisms.     

Red wine and beer elevate blood pressure in normotensive men

A positive relationship between alcohol consumption and blood pressure (BP) is well-established but the relative effect of specific alcoholic beverages is controversial. This study aimed to determine whether red wine may improve vascular function and have less of an impact on blood pressure because of its high content of antioxidant vasodilator polyphenolic compounds. Healthy normotensive men entered a 4-period crossover study comparing in random order 4 weeks of control-abstinence with similar periods of daily consumption of red wine (375 mL; 39 grams alcohol), de-alcoholized red wine (375 mL), or beer (1125 mL; 41 grams alcohol). Ambulatory systolic BP and diastolic BP and heart rate (HR) were measured together with vascular function as assessed by flow-mediated dilatation (FMD) and glyceryl trinitrate-mediated (GTNMD) dilatation of the brachial artery. The systolic and diastolic BP and HR were not different between control-abstinence and de-alcoholized red wine. However, compared with control-abstinence, both red wine and beer increased awake systolic BP (2.9 and 1.9 mm Hg, respectively; P<0.05) and asleep HR (5.0 and 4.4 bpm; P<0.05). There were no specific effects of red wine, de-alcoholized red wine, or beer on FMD or GTNMD. Daily consumption of approximately 40 grams alcohol as either red wine or beer for 4 weeks results in similar increases in systolic BP and HR. De-alcoholized red wine did not lower BP, and neither red wine nor de-alcoholized red wine influenced vascular function, suggesting that red wine polyphenolics do not have a significant role in mitigating the blood pressure-elevating effects of alcohol in men.     

The effect of wine or beer versus a carbonated soft drink, served at a meal, on ad libitum energy intake

BACKGROUND: Alcoholic beverage drinking may increase total energy intake at a meal by various mechanisms and this effect may depend on the sort of beverage. OBJECTIVE: To test the effect of wine, beer and a soft drink served with a normal meal on food and total energy intake in non-obese men. DESIGN: A supper meal consisting of three consecutive dishes was presented to 22 young men. Ad libitum energy intakes (EI) of the meal were measured at three different occasions in a cross-over design with red wine, lager beer or a carbonated soft drink. This was done in two studies with different design. In the first study the beverages were supplied ad libitum and in a second study the intake of the beverages was fixed: beer and soft drink at 9 ml/kg body weight and wine isoalcoholic to beer, 3.185 ml/kg body weight. RESULTS: In the ad libitum beverage study total EI was higher with wine than with the soft drink and beer (P<0.05). In the fixed beverage study differences in total EI did not reach statistical significance (P=0.14), although the intake of goulash was higher with wine and beer than with the soft drink (P<0.005). CONCLUSION: These data indicate that alcoholic beverages, and wine in particular, may enhance total EI at a meal relative to a soft drink, when served with no restriction.     

Effect of red wine on the intestinal absorption of thiamine and folate in the rat: comparison with the effect of ethanol alone

BACKGROUND: This work aimed to investigate, in the rat, the acute in vitro effect of red wine and the effect of chronic red wine ingestion on the intestinal absorption of thiamine and folate and to compare them with the effects of ethanol alone. METHODS: The effects of red wine and of an ethanol solution (same ethanol concentration as that in the red wine, i.e., 12% [v/v]) on rat jejunal apparent permeability (Papp) to H-thiamine and H-folate in the mucosal-to-serosal direction were investigated. Red wine and ethanol were tested both chronically (21-day consumption) and acutely in vitro. RESULTS: Acutely, both red wine and ethanol 12% (v/v) (both diluted 1:5) reduced (to 65 and 60% of control, respectively) the mucosal-to-serosal Papp to H-thiamine across rat jejunum. Chronic (21-day) ethanol (12% [v/v]) consumption also decreased the Papp to H-thiamine (to 33% of control), but red wine consumption for the same period did not change it. Mucosal-to-serosal Papp to H-folate across rat jejunum was not changed by chronic ingestion of red wine or ethanol. Similarly, it was not affected by acute exposition of the tissue to red wine or ethanol. Acute ethanol (0.05% [v/v]) did not affect the Papp to H-thiamine or H-folate in jejunal tissues obtained from control and red wine-treated rats, but it significantly increased the Papp to both H-thiamine and H-folate (to 183 and 197% of control, respectively) in tissues from chronically ethanol-treated rats. CONCLUSIONS: Acute and chronic red wine or ethanol had no effect on the intestinal absorption of folate. However, ethanol, both acutely and chronically, decreased the jejunal absorption of thiamine, and red wine reduced the jejunal absorption of thiamine, but only when tested acutely. These findings show that it is not correct to extrapolate from results obtained with ethanol alone on intestinal permeability to the effect of alcoholic beverage consumption.     

Acute effect of drinking red and white wines on circulating levels of inflammation-sensitive molecules in men with coronary artery disease

There is evidence that moderate consumption of red wine with its high content of polyphenolic antioxidants may be more protective than white wine against development of coronary artery disease (CAD). The aim of this study was to compare the acute effects of ingestion of red wine and white wine on markers of inflammation in men with CAD. Thirteen men with angiographically-proven CAD were studied in a cross-over trial. The men consumed 4 mL/kg (2 to 3 glasses) red wine and white wine in random order during a light meal and with at least a week between interventions. Later, the men also consumed an isoenergetic nonalcoholic beverage (control) in the same study protocol. Venous blood was taken at baseline, 1 hour, and 6 hours after the drinks. Plasma interleukin-6 (IL-6), vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), blood alcohol, plasma lipids, and plasma polyphenols were measured. Mean +/- SD blood alcohol was 6.5 +/- 2.2 mmol/L and 6.9 +/- 1.1 mmol/L at 1 hour and returned to baseline at 6 hours after intake of red wine and white wine, respectively. Plasma IL-6 concentration increased significantly (P =.01) during 6 hours after ingestion of red wine (56%) and white wine (63%). The increase in plasma IL-6 concentration after ingestion of wine was significantly higher (P =.045) compared with the corresponding increase (11%) following intake of the nonalcoholic beverage. Plasma IL-6 levels at 6 hours (r =.631, P =.02) were correlated significantly with plasma alcohol levels at 1 hour after ingestion of red wine. These data suggest that moderate wine intake may acutely increase plasma levels of IL-6 in men with CAD. It is possible that this increase in plasma IL-6 is a response to alcohol-induced oxidative stress in the liver.     

Moderate consumption of red wine, but not gin, decreases erythrocyte superoxide dismutase activity: A randomised cross-over trial

Background and Aims

Several studies have shown that moderate alcohol consumption reduces the risk of coronary heart disease, a disease related to oxidative stress. However, the effects of different alcoholic beverages on antioxidant status are not fully known. Our aim was therefore to compare the effects of a moderate intake of an alcoholic beverage with high polyphenol content (red wine) and another without polyphenol content (gin) on plasma antioxidant vitamins, lipid profile and oxidability of low-density lipoprotein (LDL) particles.

Methods and results

Forty healthy men (mean age, 38 years) were included in a randomised cross-over trial. After a 15-day washout period, subjects received 30 g/ethanol/d as either wine or gin for 28 days. Diet and exercise were monitored. Before and after each intervention, we measured serum vitamins, malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase activities, lipid profile, oxidized LDL and LDL resistance to ex-vivo oxidative stress. Compared to gin intervention, wine intake reduced plasma SOD activity [−8.1 U/gHb (95% confidence interval, CI, −138 to −25; P = 0.009)] and MDA levels [−11.9 nmol/L (CI, −21.4 to−2.5; P = 0.020)]. Lag phase time of LDL oxidation analysis also increased 11.0 min (CI, 1.2-20.8; P = 0.032) after wine, compared to gin, whereas no differences were observed between the two interventions in oxidation rate of LDL particles. Peroxide concentration in LDL particles also decreased after wine [−0.18 nmol/mL (CI, −0.3 to−0.08;P = 0.020)], as did plasma oxidized LDL concentrations [−11.0 U/L (CI,−17.3 to −6.1; P = 0.009)].

Conclusion

Compared to gin, red wine intake has greater antioxidant effects, probably due to its high polyphenolic content.     

The role of alcohol in the anti low density lipoprotein oxidation activity of red wine

Oxidation of low density lipoprotein cholesterol (LDL-c) is supposed to play a role in the generation of atherosclerotic lesions. Grape derived beverages supply a large number of nutritional antioxidants because of their high content of polyphenols. This might be one of the mechanisms behind the supposed beneficial effect of red wine. Wine also contains alcohol and its role in oxidation processes especially in vivo is unclear. In this study the effect of daily red wine consumption for 2 weeks on oxidizability status of LDL was investigated. The role of alcohol in LDL oxidation was further explored in in vitro experiments. After abstinence from alcoholic beverages, grape juices and tea for a week, seven healthy male volunteers consumed 375 ml of red wine (30 g alcohol) per day during 2 weeks. At the start and end of the drinking period blood samples were taken and the susceptibility of LDL-c to copper-induced oxidation was analyzed with the addition of distilled water (control) and dilutions of a 12% alcohol solution, white wine and red wine. Although red wine at concentrations achievable in vivo caused a significant prolongation of the lag-time of metal ion dependent LDL oxidation in vitro (85.9+/-23.0-114.1+/-30.8 min, P<0. 001), a significant shortening of lag-time was found in vivo after the 2 weeks of wine consumption (56.3+/-13.0 min, P<0.001). A shorter lag-time compared to the control was found for both alcohol and white wine in vitro. The changed oxidizability status of LDL after 2 weeks of wine consumption made it more susceptible for the in vitro antioxidant effect of red wine. At low dilutions red grape juice extended lag-time as well, which was not influenced by the addition of alcohol. Red wine has a strong inhibitory effect on copper-induced oxidation of LDL in vitro, while red grape juice has a minor effect, an effect which should be attributed to the non alcohol components in the beverages. In vivo, however, this effect can be overshadowed by the prooxidant influence of alcohol. The balance between alcohol and polyphenols of a wine may be critical for its in vivo effect on LDL oxidation.