Low doses of freeze-dried grape powder inhibit genes linked to the development of sporadic colorectal cancer, UC Irvine cancer researchers found. Their study suggests that a diet rich in grapes may help prevent the third most common form of cancer, one that kills more than a half a million people worldwide each year. The effective amount of grape powder used in the study equals a half glass of wine or 1 pound of grapes, which is equivalent to three dietary servings of grapes. Study leader Dr. Randall Holcombe of the Chao Family Comprehensive Cancer Center and his colleagues are currently designing a clinical cancer prevention study to see how a daily diet of 1 pound of grapes affects the genetics behind colon cancer.