In addition to the proper selection of vegetables, a few other factors may enhance their medicinal properties such as method of cooking,(or eating raw), freeze-drying, dehydration, thorough chewing or blending.
In the case of broccoli (& some other vegetables) it appears that heating at
60 °C for about 10 minutes is best as it does better than chewing raw for the release of the desirable chemicals.
http://www.newscientist.com/article.ns?id=dn3580
Eating raw broccoli may combat cancer 05 April 2003
http://www.whfoods.com/genpage.php?t...odspice&dbid=9
Broccoli
http://www.liebertonline.com/doi/abs...62004322984770
Effects of Different Processing Methods on Induction of Quinone Reductase by Dietary Broccoli in Rats
http://www.vegsource.com/harris/smoothie_veggie2.htm
Bill's Raw Vegetable Smoothie
NOTE:
People with thyroid problems may aggravate their condition by eating large quantities of (especially raw) vegetables containing natural goitrogens such as broccoli, spinach. Cooking may reduce the risk.