3 January 2000

Red wine (again)

by Kate Melville

Wine and particularly red wine seems to be a favorite topic of scientific investigation. Whether this is due to its intrinsic scientific merits or simply a proclivity for frustrated scientists to justify their personal consumption may be a good starting point for a meta research study of all the wine related research that appeared during 1999.

Anyway many reports have ascribed red wine's value to cardiovascular health as being due to flavonoids that produce benefits not reported for other alcoholic beverages. However whether the presence of alcohol in red wine enhances the benefits of the flavonoids it contains has been the subject of much speculation. A new study from the University of California, looks at how the body absorbs flavonoids from red wine with, and without, the presence of alcohol.

The research focussed on a flavonoid, catechin that is found in red wine. Five male subjects and four females consumed one moderate serving of a "red wine" beverage which had been dealcoholised but which had preserve all of its essential flavonoids, including catechin. 50% of the dealcoholised samples were reconstituted using only water, and the other half with a mixture of water and alcohol bringing the sample to the level normally found in red wine (13%). After consumption of the beverage, subjects' blood concentrations of catechin were measured at regular intervals over an 8-hour period.

In both groups catechin concentrations rose sharply for up to three hour, but persisted for significantly less time in those who drank the alcoholic version. These results may mean that the alcohol caused the catechin to be either excreted or metabolized more quickly in the presence of alcohol than in the non-alcoholic sample. The researchers conclude that the alcohol contributed no additional benefit to the presence of catechin in red wine.

So does this mean that red wine drinkers are being short changed in their possible attempts to secure cardiovascular protection - probably but that's a whole other research project. What it may mean is that those in search of catechin may have to look elsewhere, but perhaps a more important question is red wine with out alcohol actually wine anyway?