The amount of sulfites in red wine is two orders of magnitude lower than the amount in dried fruit.
Red wines contain about 50-75 parts per million of sulfites, whites contain about 100-150 ppm, and dried fruit typically contains almost 3,700 ppm (and French fries have more than 1800 ppm). Yet there is a pervasive belief among U.S. wine consumers that the sulfur dioxide (SO₂) that can legally be added to wine to inhibit microbial spoilage and to keep it from immediately oxidizing, causes headaches. Many steer clear of wine for this reason. Perhaps that’s because since 1988, a sulfite warning label has been required by law on all bottles of wine sold in the U.S. that contain 10 parts per million SO₂ or more. Andrew L. Waterhouse, a professor of enology in the department of Viticulture and Enology at the University of California at Davis has said: “There’s no data showing sulfites cause headaches. But people ascribe all sorts of nasty things to sulfites because there’s a label.” Sulfur is found in the natural environment (it’s part of the earth’s crust) and sulfites are a natural by-product of fermentation, so some amount of sulfite is going to be found in wines whether it’s added or not. Meanwhile, the FDA estimates that only about 1 percent of Americans are sulfite hypersensitive—and 5 percent of that 1 percent are asthmatics, for whom sulfites can cause difficulty in breathing. But not a headache. The so-called “red wine headache” is more likely the result of the drinker being dehydrated or of alcohol, tannins, histamines or sometimes high residual sugar, rather than the 0.005% of SO2 in the glass.