Not really. Quinine (the substance responsible for the bitter flavor of tonic water) doesn't help diabetes, so there's no significant difference between tonic water and regular soda water or seltzer.Also, some tonic water is sweetened, making it just like any other carbonated sweetened beverage.o, it often has carbonated water in it, but small amount of quinine (which is what makes tonic water glow) should be safe as it is a treatment for Ich...like 250mg per 10gal … From wiki on tonic water...