Source: www.cancer.gov Author: Carmen Phillips Numerous studies suggest that avoiding excess weight, exercising regularly, and eating a diet heavy on fruits and vegetables decreases the risk of many diseases, including cancer. But as the expanding obesity epidemic has shown, there are major obstacles to getting broad swaths of people to adopt such a healthful lifestyle. So, for many years, cancer researchers have investigated whether specific nutrients—those that epidemiologic and animal model studies have suggested could sway cancer’s course—could decrease cancer risk. Much has been learned from this work, researchers in the field say, but, as is the case with treatment, each new discovery points to new areas of focus and other potential avenues of progress. With promising bioactive compounds in the pipeline, many prevention researchers are focused on figuring out not just whether something like sulforaphane, a natural compound found in broccoli and broccoli sprouts, can kill cancer cells in a test tube or animal model—which it does, quite well—but how, at the molecular level, it accomplishes this task, whether there are some cancer cells that are more likely to respond to it, and whether there are ways of discerning early on that the intervention is having its intended effect. Prevention: A Complex Matter A number of supplements have been tested in large prevention trials, including vitamins A, C, and E; selenium; beta-carotene; and folic acid. At least one trial has demonstrated a reduction in cancer deaths with a combination of supplements, while several others found no reduction or even [...]