Lowering effects of hydroxytyrosol on homocysteine plasma concentrations after wine intake in humans

Abstract

Homocysteine is considered to be a risk factor for atherosclerosis. Moderate alcohol consumption has been associated with beneficial effects on cardiovascular diseases. However, whether these effects are due to ethanol or to non-alcoholic components of alcoholic beverages including wine is still controversial. We designed a study that tries to demonstrate that one of the most potent dietary antioxidant compounds, hydroxytyrosol is responsible for cardiovascular health benefits provided by moderate wine consumption. Instead of administering hydroxytyrosol, we will benefit from the endogenous bioconversion described by us of tyrosol, a simple phenol quite abundant in wine, to hydroxytyrosol. The aim of the present study is to evaluate the effect of hydroxytyrosol after wine + tyrosol intake on homocysteine plasma concentrations. 20 subjects at high cardiovascular risk were randomized in a crossover trial. All received: (i) water ad libitum, (ii) 1 or 2 glasses (men) of white wine (14g ethanol/glass; 1-1,25 mg tyrosol/glass) and (iii) 1 or 2 glasses (men) of white wine each supplemented with a capsule of tyrosol (25mg) in a randomized crossover design. Tyrosol and hydroxytyrosol were measured in urine two times in each intervention, homocysteine concentrations were measured in plasma and endothelial function was measured using the Peripheral Arterial Tone (PAT signal). An increase on hydroxytyrosol urine metabolites was observed after wine + tyrosol intake together with a reduction on homocysteine concentrations. No differences were observed on the endothelial function. These results support a beneficial effect of the phenolic compounds of wine on cardiovascular risk factors/cardiovascular diseases.