i think i'd like to stay away from huge amounts of those in food as well.
licorice can raise your blood pressure, even if it's just some sweets. garlic even in small amounts can make arthritis much worse. ginger is somewhat anti-inflammatory, help with an upset stomach or gas, improves blood circulation etc. i think that improvement of blood circulation is what they want to avoid before surgery. supplements may contain a lot of whatever it is, but honestly, so does my cooking... when i use garlic, the food becomes poisonous to anyone with rheumatic pain or arthritis.
i also found this about ginger:
"It has been mentioned that ginger's components may inhibit thromboxane synthesis in vitro, thus interfering with normal blood clotting (Wichtl, 2004; Abebe, 2003; Backon, 1991; Srivastava, 1989). Although the putative anti-thrombotic activity of ginger in humans has not been proven (Janssen et al., 1996; Lumb, 1994), as a precaution, suspend the use of this herb two weeks before surgery (Robbers and Tyler, 2000)."
it says herb, not supplement.