It is received wisdom that the sulfite additives in American red wines cause many drinkers to have headaches, and that the health concerns over these 21st-century chemicals are so great that wines tainted by them are required to carry an explicit "Contains Sulfites" warning.
In reality, however, nothing could be further from the truth. As is often the case when it comes to alcohol and public policy in North America, pseudoscientific groups and temperance fanatics dominate the debate. The urban myths surrounding wine are now so pervasive that cynical marketers are even using them to fob off markedly substandard wines to trend-conscious but unsuspecting Japanese consumers under the guise of a "traditional winemaking" revival. Although you'd never know it from the tone of the debate, sulfites are actually an organic compound that nature uses to prevent microbial growth. They are found on grapes, onions, garlic and many other growing plants.
Nearly all organisms, including yeasts and humans, produce sulfites as well (they are a natural byproduct of amino acid metabolism).