Evolutionarily speaking,

Would it be plausible to posit that diabetes melitis served as a protective factor for our ancestors, who millions of years ago might have found themselves in the desert without any carbohydrates to sustain their caloric needs.
Then serendipitously, dying of hunger a man decided to engage in oral cunnilingus with his mate (who just happened to have diabetes) one last time before dying, and found that he instead was invigoured and rejuvenated by the sweet taste emanating from her unique orifice?

And therefore those with DB were more likely to survive periods of famine?