I am always upset when there is a "cure" for diabetes posted online. I'm sure you are too! Cures for diabetes have been advertised for many years. H. H. Warner (1842-1923) had cures for many diseases, including diabetes. Look at the pictures of the bottle containing a Diabetes Cure. The suggested diet on the label is very good, but the content of the bottle was another "snake oil" sham.
Warner became a millionaire with his cures. There was no national health service in the 1880s, and buying a remedy from a chemist or apothecary was a standard practice. Warner had plants in Rochester, Toronto, London, Frankfurt, and Melbourne. Warner spent much money advertising, and his cures were sold all over the world. He made a poor mining speculation in 1893 and lost his fortune. Then he moved to Minnesota, where he spent the rest of his life in seclusion. The bottles containing the cures are very valuable now to collectors.