Milk Thistle (Silybum marianum), isn’t a food as such but is used as a herbal supplement in most liver tonics. If you consult with a liver specialist he/she might well prescribe a pharmaceutical grade product such as Legalon which has a measured amount of Silymarin, usually 70mg or 140 mg. This is the active ingredient found in Milk Thistle which has a proven liver cell protective action.
Interestingly, studies have found that Milk Thistle can offer liver protection to people who have consumed poisonous mushrooms or other toxic substances which have a destructive action on the liver.
I have used both Legalon and Milk Thistle extracts (not on the same day) to provide extra liver protection, primarily to prevent my fatty liver from progressing into the inflammatory (NASH) stage.