Alcohol-Free Red Wine Enhances Plasma Antioxidant Capacity in Humans

Abstract

Moderate wine consumption is reputed to exert a protective effect against coronary heart disease (CHD). The nature of the protective compounds is unclear and the mechanisms are incompletely understood. We studied whether the nonalcoholic component of wine increases plasma antioxidant capacity measured as total radical-trapping antioxidant parameter (TRAP), and whether such an effect is associated with the presence of phenolic compounds in plasma. The TRAP and plasma levels of phenolic compounds were measured in 10 healthy subjects after the ingestion of 113 mL of tap water (control) and alcohol-free red and white wine at 1-wk intervals. Both alcohol-free wines possessed an in vitro dose-dependent peroxyl-radical activity, but red wine, with a polyphenol concentration of 363 +/- 48.0 mg/L quercetin equivalent (QE), was 20 times more active (40.0 +/- 0.1 mmol/L) than white wine (1.9 +/- 0.1 mmol/L), which has a polyphenol concentration of 31 +/- 1 mg QE/L. The ingestion of alcohol-free red wine caused significant increases in plasma TRAP values and polyphenol concentrations 50 min after ingestion. Alcohol-free white wine and water had no effects on either of the plasma values. The parallel and prompt increase of antioxidant status and of circulating levels of polyphenols in fasting subjects after bolus ingestion of a moderate amount of alcohol-free red wine suggests that polyphenols are absorbed in the upper gastrointestinal tract and might be directly involved in the in vivo antioxidant defenses.

Moderate consumption of beer, red wine and spirits has counteracting effects on plasma antioxidants in middle-aged men

“…Relatively high peak plasma levels of quercetin, the predominant¯avonoid in red wine, occur within 1 ± 4 h after consumption of¯avonol rich foods (Hollman et al, 1997). This might explain the increased plasma antioxidant capacity directly following ingestion of red wine as reported by many Maxwell et al, 1994;Whitehead et al, 1995), and also agrees with the ®nding that alcohol-free red wine increases plasma antioxidant capacity (measured as total radical-trapping antioxidant parameter, TRAP) 50 min after ingestion and returns to baseline again 70 min later (Sera®ni et al, 1998). The TEAC of the red wine we used is in accordance with published antioxidant values of red wine (Verhagen et al, 1996;Campos & Eduardo, 1996).…”

The effect of whisky and wine consumption on total phenol content and antioxidant capacity of plasma from healthy volunteers

“…Similar increases in the ability of plasma to resist oxidative challenges have been observed following the consumption of wines and teas (Whitehead et al, 1995;Sera®ni et al, 1996Sera®ni et al, , 1998. Such results do not necessarily indicate that phenolics are transported to cellular sites within peripheral tissues where they could exert important antioxidant function.…”

“…Total phenols in plasma and urine were also estimated with Folin Ciocalteu reagent using a modi®cation of the method of Swain & Hillis (1959) which avoids interference from proteins in biological samples (Sera®ni et al, 1998). Plasma antioxidant capacity was estimated from its ferric reducing ability (FRAP) where development of an intense blue colour resulting from the conversion of a Fe(III)-2,4,6-Tri(2-pyridyl)-s-triazine (TPTZ) complex to Fe(II)-TPTZ is directly related to the amount of reductant present (Benzie & Strain, 1996).…”

Effects of blueberry and cranberry juice consumption on the plasma antioxidant capacity of healthy female volunteers

“…Several studies have reported increases in antioxidant capacity of plasma following consumption of antioxidant-rich fruit, vegetables, teas, wines and grapejuice (Whitehead et al, 1995;Benzie et al, 1999;Kivits et al, 1997;Sera®ni et al, 1998;Duthie et al, 1998). This effect has been ascribed to the low molecular weight phenolics in many plant-based foods which can act as antioxidants because their extensive conjugated p-electron systems allow ready donation of electrons or hydrogens from the hydroxyl moieties to free radicals (Scott, 1997).…”

“…Total phenols in plasma and urine were also determined with Folin-Ciocalteu reagent, using a modi®cation to remove protein interference in the samples (Sera®ni et al, 1998). Vitamin C concentration in plasma and juice was measured by high pressure liquid chromatography (Ross, 1994).…”