What are Sulfites?

Sulfites are another preservative found in foods, but they are also naturally occuring (most wines have naturally occuring sulfites in them, which is why they give me a nasty headache). They are counted in the top nine for food allergens. The trouble is though, the reaction is not a true allergic reaction and most people would not test positive for sulfites on an allergy test. People at risk for having reactions are asthmatics and people who have sensetivities to aspirin (salicylate sensetivity). The reaction can be quick and severe including respiratory distress and even anaphalaxyis.

The problem here in the U.S. is that sulfites may not be labled on food products, and often are not. According to Wikipedia:

In the U.S., labeling regulations do not require products to indicate the presence of sulfites in foods unless it is added specifically as a preservative;^[7] however, many companies voluntarily label sulfite-containing foods. Sulfites used in food processing but not specifically added as a preservative are only required to be listed if there are more than 10 parts per million (ppm) in the finished product. The products most likely to contain sulfites (fruits and alcoholic beverages less than 10ppm) do not require ingredients labels, so the presence of sulfites is usually undisclosed.

So chances are you consume them. On a regular basis. And don't realize it. And, you may not even be aware that you have a sensitivity to them. This is something I know I've battled with on a personal level. My mom has been a long time sufferer of horrific headaches related to foods with MSG and with sulfites and I myself will get a profound headache if I consome them in great quantity (a glass of wine has me whipped).

They have been used for years as a food preseravitive as they do extend the shelf lives of food significantly. Sensetivities can develop at any time during a persons life span and you may never be aware of what it is that is causing you to feel poorly. It is important if you have a reaction, to talk to your doctor about it. As I said previously, it's hard to know exactly what these are found in, and sometimes they are there purely by nature. Not everybody will react severely and there's a "trigger point" of exposure that is different for everybody who does have a sensetivity. It's something to be mindful of though, especially if you have asthma.

Here is an FDA guideline of foods that MAY (even they're unsure) contain sulfites:
http://extoxnet.orst.edu/faqs/additive/sulf_tbl.htm