sorry, i wrote the answer in the wrong section, wanted you to get the message:
hello
i have been experimenting a little on my own one might say.
I have found that in order if you eat fermented cheese (blue and white at least) and combine this with huge amounts of smoothies of carrots, a little bit of epsom salt and what ever else kind of plant parts your body might have a craving for, it will directly effect the pancreas. The cheese is high in pro-biotics (related to absorbtion of vitamin K2 and B12). Also i have eaten loads of vegetables (some fermented) and some raw pressed oils like coconut, hemp and olive for a long time now (oils relate closely to fat soluble vitamin absorbtion)...
i also eat a lot of fruit and some white mushrooms (champignon) and at a time i drank loads of salt water. Basicaly no bread or seeds (legumes, grains, rice, corn, nuts etc.) and no meat though i don't know exactly how this effects the pancreas.
The amounts of vegetables i eat seem to fill me up way to much for me to eat anything else. eating less bread and adding a little epsom salt to water may reduce your sexual activity, and the first time i added it i got a bit of diarrhea, but i could feel something happening in my liver, and it was a good feeling in all.
As you say copper and beta carotene is higly linked to diabetes, and i have jet to see anyone with red hair having diabetes type 1, but that is only my experience.
as you say also zinc is importent for bones and teeth especially, and therefore there should be a balance in what you eat.
mint and avocados are pretty nice with zinc amounts. I never eat something if it tastes bad or not taste anything at all.
I also ended up using the chart of chakras as a tool for what i eat, and it is doing wonders for my body. But i mostly listen to my body's needs as of now. I think all of this is closely related to diabetes type 1.
Here are some interesting articles that you might like:
Epsom salt and sulfur
https://www.westonaprice.org/health-topics/abcs-of-nutrition/sulfur-deficiency/
Pro-biotics and diabetes
https://www.sciencedaily.com/releases/2015/01/150127104850.htm
i hope this aids you in some way. thank you for reading
i'm sorry but i haven't seen any articles on the type of research you are asking about, copper and beta-carotene, so i'm hoping that someone else can give you some insight into the problem. i have checked all the books i have on diabetes, which are many, and also many of the magazines about diabetes i get. i have never had a doctor bring up these substances in exam/conversation meetings. good luck, bret