Reluctante.......I THINK NOT!!! If that were the case, then so would cheese and other dairy products cause diabetes.
Type 1 Diabetes IS NOT caused by food of any sort. It is an autoimmune disorder in wich the body rejects it's own cells and destroys them.
Where folks like you come with with crazy ideas like that is beyond me. And if it were as simple as that, then someone would have already won the noble prize for cureing diabetes.
As for the milk question, if his doctor says it's ok for him to drink milk (being he has no allergies or adverse reactions to milk) then I see no reason why he can't drink it. However, as the previous poster said, make sure you take in the carb readings into his meal plans. Nothing wrong with drinking milk so long as it's in moderation like other foods.
First off, Milk has 12 grams of sugar, a fact that many of us ignore. Doesn't matter what fat percentage it is, it still has 12 grams.
I'm not a doctor but a very knowledgable friend of mine informed me that there are certain proteins in milk that the human body rejects. These proteins have a very similar build to the protiens in insulin, which the body later recognizes as the foreign protein. When the body recognizes insulin as that foreign protein it starts rejecting the insulin the body produces, causing diabetes in some people.
This information is well known outside of the country, but has not been released here due to the fact that it would hurt the dairy industry.
My teenage daughter is a type 1, and her nutritionist said milk was great, as long as she counted the carbs and covered it with insulin. She drinks milk with dinner regularly. Milk is a great food, especially lowfat/fat-free milk. Are you covering your son's milk with insulin? As long as you cover the carbs in the milk with insulin, he should be able to drink it. It's much better for a diabetic than juice or soda.
I would talk to your doctor about adjusting insulin levels to allow for the milk, and it should work out. Good luck to you.