Hi Lol,
Sorry, can't help you on the mannanon. I tried googling it but came up with nothing, and a search on the Revital site came up with no matches. Are you sure that is how it is spelled?
There are conflicting views about coffee and diabetes. Headlines in 2006 said "Coffee may protect against diabetes". More headlines in 2008 said "Coffee may make diabetes worse"
I think the vital clue in both articles is the word "may". What that means is they haven't a clue! You could just as easily say "if I flap my arms up and down hard enough I MAY be able to fly".