The sugars in fruits are the kinds of sugars that you should be putting in your body vs. the complex processed sugars found in things like candies, cookies, and pastries. Fruits contain fructose in its natural state. They also contain fiber and a lot of vitamins and minerals. If you are diabetic or on some sort of diet in which you have cut sugar completely out then consuming is still consuming sugar and you could witness a spike in your blood sugar level because of it.
Someone that is diabetic should limit their fruit intake and research which fruits are best for them to consume. At any rate consuming fruit sugars is the healthy way to consume sugar if you are going to.