After a long winter, spring has finally arrived. For many wine drinkers, that means more white wine on the dinner table. And a new health study by Italian researchers suggests that wine doesn't have to be red to keep your heart healthy.
For decades now, as research has shown that moderate consumption of wine offers health benefits, red wine has gotten most of the glory. Red wines are more often recommended because they have higher concentrations of polyphenols, organic compounds that are powerful antioxidants.
Grapes contain numerous polyphenols—in their skins, seeds and juice—and some get passed along to wine. Skins in particular are rich in the compounds, including the one getting the most attention in recent years, resveratrol. Because red wines macerate on their skins, soaking up compounds, they have higher concentrations of resveratrol and other skin polyphenols.
But does that mean white wine is nothing more than delicious? No. Numerous studies have shown that alcohol itself has cardiovascular benefits, reducing the risk of heart disease and stroke. And white wines contain polyphenols too.
For the latest study, researchers from multiple Italian institutions, including the University of Turin and Versilia Hospital in Tuscany, focused specifically on the polyphenol caffeic acid, found in both reds and whites. One hypothesis for the link between wine and a lower risk of cardiovascular disease is that polyphenols encourage blood vessels to produce more nitric oxide.
Nitric oxide is a vasodilator—it relaxes arteries, lowering blood pressure, which can prevent numerous cardiovascular diseases as well as diabetes and chronic kidney disease. Nitric oxide also helps makes platelets less sticky, which reduces the risk of plaque forming on artery walls.
Normally oxygen in the bloodstream reacts with nitric oxide, making its effects short-lived. But the scientists theorized that antioxidants like caffeic acid protect nitric oxide in the blood and stimulate cells to produce more of it. For the study, the team dosed both mice and human blood vessel cells grown in the lab with caffeic acid, then measured nitric oxide levels and, in the mice, cardiovascular function.
The results, published in the online journal PLOS ONE, showed that blood vessels in both mice and the lab produced more nitric oxide. The antioxidant improved arterial health and reduced the risk of kidney disease in the mice. "The results of the present study suggest that caffeic acid–induced nitric oxide availability may explain, at least in part, the potential [cardiovascular] protection associated with moderate white wine consumption typical of a Mediterranean diet," wrote lead authors Massimiliano Migliori, of Versilia Hospital's Nephrology and Dialysis Unit, and Vincenzo Cantaluppi, of the University of Turin's Department of Medical Sciences.
The research is still preliminary—more work is needed to understand caffeic acid's effects. Further studies would also need to explore how much caffeic acid humans absorb from wine and whether it's as effective. But with the weather warming up, you shouldn't feel less healthy for opting for a glass of vibrant Vermentino over a rich Cabernet.