My friend Brenda's work involves research studies for a prominent urologist. She forwarded an e-mail that suggests cooked asparagus may have cancer-fighting properties:
Asparagus contains a good supply of protein called histones, which are believed to be active in controlling cell growth.... That accounts for its action on cancer and in acting as a general body tonic....It has been reported by the US National Cancer Institute, that asparagus is the highest tested food containing glutathione, which is considered one of the body's most potent anticarcinogens and antioxidants.
Cooks asparagus (canned or fresh), blend to a puree, refrigerate, and take 2 Tbsp with breakfast and dinner, mixed with water, as a preventative tonic.