No, but there is plenty of evidence that fungi develop resistance to anti-fungal drugs. If I really liked zest I might keep eating it, but since I actually don't like it in the first place I don't find that I lose anything by leaving it out of recipes and cocktails.

I certainly wouldn't say that it's definitely harmful, but when you're eating all these fungicides that have never been tested for longterm safety on humans then that's a risk one should be at least cognizant of.