You asked how we found out my husband's intolerance. It was totally by accident. Last year, an osteopath noticed his swollen eyes and bloated stomach, said it might be gluten and / or dairy intolerance and suggested he started a gluten and dairy free diet. After some reluctance, we decided to give it a try. Since we used to have bread, cheese and wine at the same time, we also stopped the wine. After three weeks, my husband started "unbloating" and feeling better and then noticed that his asthma was subsiding. However there were days when he'd still go to bed with a tightness in his chest or wake up with swollen eyes and we couldn't figure out why until we made the connection: wine = sulfites. We googled "swollen eyes and wine " and found a site, holdthesulfites.com, where a lot of the described symptoms applied to him. Further research showed us how widely sulfites are used in the food industry and even though I cooked most of our meals, I was using ingredients that were a problem, such as vinegar (I have since switched to rice vinegar), corn starch, certain spice mixes, shell fish, and others. I am not a doctor, but all I know is that after a year of trial and error, and switching to unprocessed, untreated, natural ingredients, his post nasal drip and allergies have really gone away. I am only guessing that before his body was on overload, in a state of constant inflammation and couldn't fight the allergens brought by pollens and so on. This is only a testimony of what has happened to us. I am hoping that some day the medical field will look into this . In theory, only 2% of the population is allergic to sulfites. I suspect that a lot more people are affected although not really allergic. You might ask: why doesn't he get tested ? Well, he could but we live in France and there is only one hospital here doing that kind of test and it is a six hour drive... In any event, it is a well established fact that anyone will benefit from homemade food as opposed to ready-made. So I highly recommend it !