Wine, beer consumption and homocysteine. The SU.VI.MAX study

Homocysteine concentration (tHcy), even when it is slightly few above the normal range, is a predictor of risk of cardiovascular diseases. It probably increases with alcohol consumption. But results diverge according to the level of alcohol consumed ("J. shaped curve"), alcohol type and the population studied. An inverse association between folate status and tHcy is now well established. It is explained by the role of folic acid in re-methylation of homocysteine to methionine, the main metabolic pathway of tHcy elimination (with vitamin B12 as co-transporter). The other one is the catabolism pathway via trans-sulphuration unto cystathionine, with vitamin B6 as cofactor. In order to clarify the positive effects of a moderate alcohol consumption on cardiovascular disease, we have investigated the relationship between tHcy and alcohol intake, taking the different types of alcoholic beverages into account. In 1196 middle-aged women and men of the SU.VI.MAX study, an intervention study on the effects of antioxidant supplementation on chronic diseases, tHcy and red blood cell folate were measured. Intake of alcohol, energy, coffee and B-vitamins was assessed by 6 dietary records. Total alcohol consumption was positively associated with tHcy in both sexes (p < 0.05). In women, tHcy was positively associated with wine intake (p = 0.01) and in men with beer intake (p = 0.002). No association was observed with the consumption of spirits. The association between beer consumption and tHcy in men was modified by the consumption of wine. In wine drinkers the association was positive, while an inverse trend was observed in those who did not drink wine. Red blood cell folate was associated with wine drinking in men (p = 0.07) and with spirit consumption in women (p = 0.02). The results of the present study could suggest that wine consumption may increase tHcy, while beer consumption seems to have no (or even an inverse) effect on tHcy. These results could be explained first by the much higher consumption of alcool in wine drinkers than in beer drinkers, (except those who are also wine drinkers). Then, folate status, even with a good level, cannot be sufficient to reduce tHcy in the whole group of wine drinkers, given the important number of large alcohol consumers included in this group. The protective effect of folates could also follow a "J shaped curve" and be efficient only when alcohol drinking is moderate.