I won't call it a cure, and it's not as effective as dieting (in the morning I have 100s from 1500 calorie diet, 120s from 2500-3000, and 130s-150s if I'm bad and start actually gaining weight), but I've noticed that one can (~400 calories) of jack mackerel drops my blood sugar by 10 points for maybe 3-18 hours after eating. Based on about 4 repetitions so far, so this might still be a flash in the pan, but without out and out fasting for days (or overshooting after a meal) I find it very hard to get down to the 90s in blood glucose (which I think I can feel in my arms just above the elbow, in the lower end of the bicep) and it's happened 4 times after eating this one particular food. This doesn't happen with any other fish I eat, and I've been eating all sorts of fish (flounder, sardines, especially). Also not noticed with any other fish I eat is that the mackerel gives my urine a noticeable fishy odor. I would hypothesize whatever the smell is is a pretty decent anti diabetes drug.