You'll see one of two sulfite notifications on a wine label:
Contains Sulfites or
Contains No Added Sulfites. Contains Sulfites indicates the winemaker added sulphur dioxide to help preserve the wine. Contains No Added Sulfites indicates the winemaker decided on letting the natural sulfites take care of preserving the wine. If you get a wine without added sulfites, don’t plan on keeping it in the cellar very long. Wine made without added sulfites—especially white wine—is much more prone to oxidation and spoilage.
Occasionally a customer will state they cannot drink red wine because the sulfites cause headaches so they always opt for white wine. Red wine contains tannins which comes from the grape skins, seeds and stems. Tannins act as antioxidants and preservatives so less sulfite is needed in red wine then white wine. Since white wine has higher levels of sulfites, evidence suggests that the headaches are caused by some other substance in red wine such as the tannins, histamines or alcohol.
According to the FDA, a small percentage of the population (about 1%) are sensitive to sulfites--most of them are asthma sufferers. Reactions can include swelling, hives, asthma, and migraines. If you have a sulfite sensitivity, you probably want to avoid wine. But you’ll also want to steer clear of soda, candy, prepared soups, frozen juices, processed meats, potato chips, French fries and dried fruit, all of which contain much higher concentrations of sulfites than wine. The following chart shows comparisons of different foods and levels of sulfites.