ive seen plenty of studies showing that milk thistle is benificai for the liver, ive seen none supporting the kidneys. milk thisle contians siliymarin which help to protect and regenerate liver cells and it increases protien synthisis in the liver. it is also a very potent antioxident more potent than vitamin e so that explains a little bit why its good for the liver cuase antioxident are all good for the liver. ( vitamin c,e, alpha-lipioc adic)
in fact ALA is probably better than milk thistle for the liver.