There's no provable connection between Type 1 and sugar consumption. There is however a chemically provable connection between high fructose corn syrup and all sorts of diseases including Type 2, but that's another story.
I'm not going to argue the point too much, but why do babies get Type 1 when they are exposed to very little solid food, including sugar? Why do so many obese people NOT get any form of diabetes? Why do healthy people who do not eat sweets, and have a very healthy diet, get Type 1? Why is Type 1 more prevalent in colder climates?
Sugar consumption has nothing to do with it.
All carbohydrates, including sugar get converted to glucose in the body. The molecules are no different in the blood stream if you eat a bunch of potatoes, a bowl of salad, fruit, a bar of chocolate or even a piece of protein or a tub of butter, (a % of protein and fat also get converted to glucose - see posts on TAG). Glucose is glucose!
Insulin converts all food in some proportion to glucose. So, you could just as easily say that over-consumption of potatoes or fruit or tubs of butter got you the diabetes. Sugar is half fructose and half glucose that, like everything else, ends up as glucose in your blood stream. So I'm wondering how's it possible that only the sugar you ate can cause Type 1 diabetes?
Just a general point - people talk about a 'weakened immune system', when I suspect it's the opposite - one that is producing too many antibodies, and the wrong ones at that. Maybe we should be calling it a 'faulty immune system' rather than a weakened one, in which the antibody response would be lacking.