Personally, I’m comfortable eating fresh raw (and powdered raw) oyster mushrooms (currently) based on my own research (unless future studies persuade me otherwise).
I cook button, portobello and cremini mushrooms (Agaricus) which are the most common source of agaritine the mycotoxin which is believed to be cancer-causing. I also cook other varieties of mushrooms to be on the safe side since I’ve only researched oyster mushrooms in terms of safety and in relation to their beneficial effect on rheumatoid arthritis. Cooking mushrooms breaks down a substantial amount of the agaritine, as does refrigeration and drying.
There’s also evidence to show that cooking mushrooms may increase nutrient availability and absorption, and of course it generally improves the flavour too :-)
By the way, button, portobello and cremini mushrooms are all the same mushroom at different stages of growth. I didn’t know this before, I only found out while doing some additional research for this post :-) Read more . . .