Q. Occasionally I have a glass of red wine after dinner, but I always get a headache afterward. (White wine doesn’t have the same effect.) Why might this happen? A. Scientists aren’t entirely certain why red wine headaches are so frequently reported. But they’re zeroing in on a flavonoid called quercetin that’s abundant in many fruits and vegetables, including the grapes used to make red wine. Flavonoids are typically a good thing, since they boast antioxidant and anti-inflammatory properties