
I can't see any great issue with dandelions, although has been said they are can have a diuretic effect, and act as a tonic for the kidneys. From my greenfood-gathering days as a rabbit owner, I recall they can be laxative in large quantities.
The young leaves are often eaten as a salad vegetable in France and other countries, though they are often rather bitter even when quite tender. You can imagine my horror as a 13-yr old French Exchange student when the mother of the family I was staying with went picking dandelions, and served them up for dinner!
They also contain high levels of Prebiotics, so as such are good for digestion, and I have sometimes included a few fresh leaves in the blitzed veg mix I make up for my raw fed dogs, but rather the dogs than me!
I have read that some people have an extra-heightened sense of bitterness, due to different tastebuds and that might explain why I couldn't eat the dandelions, plus as a child I couldn't eat my grandfather's home-grown lettuces either - to me they were mouth-puckeringly bitter, but my parents thought I was just being fussy. I've had similar experiences with the leaves from home-grown celery, and have never ever been able to drink "Bitter" beer.