- Members of the Chapkin lab at Texas A&M University at College Station, Texas, have investigated the impact of dietary fat and fiber on the cellular signaling cascades in the colon. Chapkin demonstrated that omega-3 fatty acids regulate the transmission of information that alters physiological responses thereby determining the risk for developing colon cancer. An unexpected outcome of ongoing studies was the demonstration that the protective effect of omega-3 PUFA with respect to colon tumor development was enhanced when highly fermentable pectin was added to the diet. This chemopreventive effect was mediated in part by the up-regulation of targeted apoptosis of DNA adducts during tumor initiation and spontaneous apoptosis during promotion. These data indicate that highly fermentable fiber only has chemotherapeutic value when omega-3 PUFA is the lipid source. This observation provides another unique mechanism by which omega-3 PUFA promotes apoptosis.