Here's a toast to the good tidings that the occasional glass of wine is something of a health drink. May your favorite Merlot, Cabernet Sauvignon, or Pinot Noir keep your heart strong, your HDL cholesterol high, and, possibly, your brain cells active and well connected! Alas, for some, that toast would be a preamble to a throbbing headache, especially if the wine is red. The red wine headache is a real-if poorly understood-phenomenon.
The Sulfite Story
Sulfites are possibly to blame. They are compounds that contain sulfur and a less-than-optimal number of oxygen atoms. Consequently, they "grab" oxygen before it can react with food and spoil it. In wine, sulfites also control bacteria that might otherwise digest the alcohol content, turning a $50 bottle into some very expensive vinegar. Some sulfites are created naturally during fermentation, as the yeast breaks down sugars in the grape juice into alcohol and carbon dioxide. But wine makers often add more as a preservative.
Sulfites were once considered harmless, but in the 1980s, studies started to show that a small number of people (about 1%, according to the FDA) are sensitive to them. The FDA, therefore, prohibits the use of sulfites on fruit and vegetables intended to be eaten raw, so salad bars and your supermarket's produce section should be sulfite-free. Depending on their concentration levels and other factors, the sulfite compounds must be included in a food's list of ingredients. Most wines are emblazoned with a "contains sulfites" warning.