People can take supplements -- vitamin A, and you can get beta-carotine.
Also, I think for foods it's not just the sugar content that counts, but the glycemic content, some have sugar, but still don't raise blood sugar, others do.
http://www.diabetesnet.com/diabetes_food_diet/glycemic_index.php
Thanks for that link (diabetes.net in Post 7), am going to check it out.