Funny thing about food allergies ... it causes you to look at your own diet, and your body's reactions to certain foods, much more closely. For instance, after we discovered Ainsley's food allergies, I discovered that I was actually slightly allergic to sunflower seeds (I found this out after I tried some Sunbutter for the first time and my mouth got very itchy. The last time I ate sunflower seeds I got the itchiness plus a bad stomach-ache). I also developed an intolerance to chickpeas/garbanzo beans - I started getting terrible stomach cramps after eating them (my reaction to them grew worse over time, probably because I had really never eaten them until I started cooking with them to give Ainsley more protein; once I started ingesting a lot of them, I started feeling worse and worse each time I ate them).
Now we have discovered another potential food issue in our family: Dave might be lactose-intolerant. He has noticed that, over the past few months, he would suddenly get nauseous and, at times, throw up after eating a meal. He had no idea what was causing it, so he decided to monitor what he ate. He just called to tell me what he thinks the culprit is: cheese. He doesn't ever drink milk or eat ice cream; the only real dairy he consumes these days is cheese, and it's not that often because we eat dairy-free at home. Today he ate a cheeseburger for lunch and felt ill. Lately, he's felt the same way after going to Mexican restaurants, where he loves to order queso. He is going to visit his doctor soon to discuss this possibility and, if it is lactose intolerance, find out how to deal with it.
I am wondering if the fact that we've seriously reduced our dairy intake in the past few years might have caused Dave to lose the ability to digest milk. I know you need a special enzyme to digest dairy; could he have lost it from not eating dairy on a regular basis? I am curious whether, for instance, vegans who decide to reincorporate dairy into their diets have these problems? I will definitely be looking into this further.
Update - okay, I've done a little research on the internet, and it suggests that cutting dairy out of your diet probably won't cause lactose intolerance. But the older one gets, the more likely he is to lose his ability to digest lactose, so it might just be that Dave has reached the end of the road in terms of his ability to digest dairy.