Medical College of Wisconsin, USA
Title: Chemoprevention of gastrointestinal tract cancers with berries
Gary D Stoner completed his PhD at the University of Michigan in 1970, conducted Post-doctoral studies at the University of California-San Diego and, in 1992, joined the Department of Preventive Medicine at Ohio State University as Lucius Wing Chair in Cancer Etiology and Prevention. He has Chaired the NIH Chemo/ Dietary Prevention and the ACS Nutrition and Environment Study Sections. He is Professor of Medicine at the Medical College of Wisconsin and is conducting additional clinical trials of berries for the prevention of esophagus and colon cancer. He has more than 300 peer-reviewed publications. 55 book chapters and has edited 4 books.
We examined the ability of freeze-dried berries to prevent G.I. tract cancers in animals and humans. Most studies used black raspberries (BRBs), due to their high antioxidant potential and high content of anthocyanins and fi ber. In rodent studies, the consumption of BRB powder, at 2.5, 5 and 10% of a synthetic diet, resulted in a 40-70% inhibition of carcinogeninduced cancer in the rat esophagus and colon, and the spontaneous development of intestinal tumors in mice. Mechanistically, BRBs inhibit proliferation, infl ammation and angiogenesis and stimulate apoptosis and diff erentiation, and protectively modulate genes in multiple signaling pathways. Th e most active inhibitory constituents in BRBs are the anthocyanins. A Phase I trial showed that BRBs are well tolerated in humans at oral doses that elicit chemopreventive eff ects in rodents. Th e oral administration of BRB powder (45g/day) to 20 Barrett’s esophagus patients for 6 months led to reductions in oxidative stress, but minimal eff ects on the lesion. Oral administration of strawberry powder (60g/day) to 37 Chinese patients with esophageal dysplasia led to histologic regression of ~80% of mildly dysplastic lesions and reduced levels of iNOS, COX-2, and phospho-NF-κB-p65 proteins. Treatment of 20 colorectal cancer patients with BRB powder for an average of 3 weeks led to reduced cell proliferation and demethylation of suppressor genes in the Wnt signaling pathway. Treatment of patients with familial adenomatous polyposis with rectal BRB suppositories caused a 36% regression of rectal polyps. Th ese trials indicate that berries have signifi cant promise for chemoprevention of esophageal and colon cancer in humans.