Interesting. I suffered from canker sores into my early 20's. Finally talked to a Dr, who sent me to a nutritionist. The problem for me was orange juice. I've never been sure what exactly it is in OJ that caused the problem. But I do know that if I drink a glass of processed orange juice today, I'll wake up with a bad canker sore in 2-3 days. If I drink a glass of fresh orange juice for a few days in a row, I'll get the canker sores.