Not just anyone off the street is qualified to be a pharmacist or a doctor. So in this context "Doing your own research" means allowing dunning-kruger biases into your medical decisions.

A fool doing research may conclude this to be a healthfood, given the sources they take in. For example, the packaging of the product.

"That's silly, who could ever trust the packaging?" -- well, someone who also suffers from that dunning-kruger effect right?

I'd guess they mean that the kind of people who think they are competent to do their own research are exactly those who are not.