It has long been recognized that dietary factors influence the risk of developing colon cancer, with populations consuming a higher proportion of fruits and vegetables having lower risk. A compound found in the skin of grapes, resveratrol, has been purported to have colon cancer prevention activity though the dosages obtained through the diet have always seemed too low to produce inhibitory effects against cancer cells in the laboratory. We have found that low concentrations of resveratrol inhibit the Wnt pathway, a key signaling pathway which is activated in over 85% of colon cancers. We have also found in a small pilot trial that low dosages of freeze-dried grape powder can directly inhibit Wnt signaling in the normal colon and that grape powder was more effective than resveratrol alone in blocking Wnt throughput. This suggests that components of grapes may have direct activity in inhibiting a key signaling pathway and that this may correlate with cancer prevention activity.