Natural sources often contains "antidote" which could be as simple as shell, fiber or cellulose, something to limit your consumption. For example sugar cane is

Natural sources often contains "antidote" which could be as simple as shell, fiber or cellulose, something to limit your consumption. For example sugar cane is a wooden stick. You would have to chew it with your measly human teeth for hour to get the sugar out of it. But if it's processed into sugar powder, you don't need to chew. By processing you lost the "antidote" that would otherwise moderate your consumption. Xylitol is found in birch tree. Good luck eating birch tree.