It's the sulfites that give you a headache. Most wine that is made in France etc doesn't have sulfites until it has to be imported to the US. It's a law but I don't remember the reasoning behind it. Anyway, if you ever travel to Europe give it a try over there and you may not have the headaches lol
I might gently disagree with you regarding sulfites. All wine has some sulfites given that it is a natural by-product of the type of fermentation used in wine-making. Generally speaking, all winemakers use additional sulfites (including those in Europe, New Zealand, Australia, South Africa, and the U.S.) to help with the preservation of a product that can go bad quickly even when sealed in a bottle. Indeed, the European Union standards for sulfites are virtually the same as those for the U.S. and other winemakers worldwide.
Much higher levels of sulfites are found in such things as dried fruit and instant potatoes, so unless someone has found themselves allergic to such things, sulfites are likely not the cause of any headaches. Further, most sweet white wine has more sulfites than drier ones, and in some cases, they have more than even a red wine. As for the sulfites themselves, while it is true that some people have an allergic reaction or sensitivity to sulfites, the baseline is somewhere around 1% of the total population at best, and in those cases, the results are much like an allergic reaction such as rashes and swelling.
The more likely culprits are either tannins (the element of most red hearty red wines that give you that pucker sensation) or histamines--both of which naturally occur in wines, especially reds. For both of those elements, there are those who don't tolerate either (or both) well. In truth, no one is totally sure just what causes red wine headaches as no thorough study has been done to this point.
If someone wishes to drink red wines but avoid the headaches, I might suggest less tannic reds such as Lambrusco, Gamay, Garnacha (aka Grenache), or Pinot Noir. Even then, depending on the winemaker's process, you still might feel the bite of the tannins, especially in the last two wines. Thankfully, I get no such headaches--I just am one from time to time.
