I see really healthy foods can inhibit detox enzymes like SULT. Does this mean I should avoid eating them?

Absolutely not. The beneficial role of eating a diet rich in fruits and vegetables is very clear. The many benefits derived from fiber content, vitamins, minerals, antioxidants and other phytochemicals greatly outweigh any downside from slowing enzymes like SULTs. No large scale case-control studies have been performed to understand the impact of flavonoid consumption in associations between various cancers and SULT1A1 genotype, despite the fact that these flavonoids are both substrates as well as potent inhibitors for this enzyme. This complex dietary component may explain the inconsistencies among numerous research findings for SULT variants even after the role of gender, hormonal use, ethnicity, gender, parity, processed meat and exposure to tobacco or occupational chemicals have been controlled for.