When it comes to health benefits, red wine tends to get most of the credit.
Cardiovascular benefits have been ascribed to alcohol itself (find a reasonably readable and full-text review here, courtesy of the Journal of the American College of Cardiology). But, of late (as in, say, the past decade), resveratrol has attracted the most attention; as a potent antioxidant, it truncates the chain of events involved in endothelial plaque formation (“hardening of the arteries”). Resveratrol is much more concentrated in red wine than in white. But resveratrol is a polyphenol, one of many. And polyphenols in general, and both red and white wine, have circulatory system benefits in lab studies we can ascribe to other causes.
For instance, NO, which is to say nitric oxide. Polyphenols encourage artery-lining cells to produce more NO. We know NO both as laughing gas and as a potent (if short-lived) vasodilator. NO tells the artery muscular to relax, which increases vessel diameter and lowers blood pressure. Arteries that no longer relax properly are a feature of many cardiovascular diseases and part of the cascade of interrelated faults that progressively damage both the heart and organs like the kidneys and eyes that suffer damage from blood pressure that’s consistently too high. NO also helps makes platelets less sticky with the effect of gently working against that damaging plaque formation.
Antioxidants, including polyphenols, increase NO levels indirectly by countering oxidative molecules that can rapidly destroy NO in the bloodstream. Polyphenols also stimulate NO production directly, and arteries benefit by learning to relax and suffering clogs less readily.
A paper just out in PLOSOne (always and ever open access) convincingly adds to evidence that caffeic acid, a polyphenol in which white wines are particularly rich, increases arterial lining NO production. The research team demonstrated that caffeic acid increases NO, but also that it improves arterial cell function and slows kidney disease damage in mice. Translating caffeic acid-dosed mice to white wine-dosed humans is still a leap we’ve not yet made, but it’s a likely one. Doses mice received were along the lines of what a moderately-drinking wine lover might ingest, and these sorts of mouse experiments have worked well to model human arterial disease in the past.
In short, there’s a good argument to be made that white wine is good for your heart. As good as red? That’s going a step too far, and not least of all because individual wines vary so much in their concentrations of resveratrol and caffeic acid and total polyphenols that we’d need to compare individual wines rather than try to stereotype by color. But the next time someone tries to talk you out of a glass of Chablis or riesling in favor of the red option for the sake of your health, don’t let them. You know more than they do.
In other news: three useful-if-not-groundbreaking reviews arose in recent days, on biotech uses for winery waste products, causes of and solutions for protein hazes, and polyphenols found in oak. Details are here.