I am allergic to beef, eggs, milk, fish, lettuce, tomatoes, peppers, apples, bananas, peaches, pears, wheat, corn, honey and artificial sweeteners. What do any of them besides the beef and milk have in common? Makes eating anywhere but home a challenge. And yes an allergist diagnosed me.
The chemical is destroyed during cooking ~ and yes, people eat the inner bark of birch since it's nearly pure sugar.