• 3/7/2007
  • Columbus, OH
  • Glen Forbes
  • The lantern (media.www.thelantern.com)

Dale Stokes owns a 230-acre farm in Wilmington, Ohio, but he is also in the business of saving lives.

Stokes is the main berry provider for cancer researchers at Ohio State who are attempting to prove that consumption of certain berries, particularly blackberries, black raspberries and strawberries, can stop the spread of colon, esophageal and oral cancer.

“I would estimate that I’ve given about 15,000 pounds of berries over 20 years to this research,” Stokes said. “To ensure consistency, I grow all of the black raspberries at Ohio State in the same patch of roughly three acres.”

Several groups of researchers based at the OSU Medical Center are studying the effects of berry consumption. Black raspberries and blackberries have proven to be particularly effective in reducing the size and spread of tumors in rats with oral and esophageal cancer, according to Dr. Gary Stoner. He has led the research regarding the positive effects of antioxidants in berries for more than 20 years.

“I first heard about Dr. Stoner’s work in 1987 when he was with the Ohio College of Medicine in Toledo,” Stokes said. “I heard what he was trying to do and I approached him and told him I was the largest individual grower of black raspberries east of the Mississippi.”

In the early 1980s, Stoner and his research group began working with a compound that featured ellagic acid – a plant nutrient that is plentiful in several types of berries.

“We started talking about possibly preventing cancer with berries rather than ellagic acid, which is not in the juice of the berry, but in the seed and the pulp,” Stoner said. “The concentration of ellagic acid in the berries increase tenfold by taking out the water. And we said if we embark on this we need to identify a single source to standardize this as much as possible.”

The first berries used for research were picked, frozen, placed on a drying apparatus, freeze dried and ultimately pulverized into a berry powder. The powder was then added to the diets of animals with colon and esophageal cancer.

“We found the powder was striking at inhibiting new blood cells that cause cancer to spread, with between 40 and 60 percent effectiveness for esophageal cancer,” Stoner said. “We extended the studies to colon cancer and found the powder was more effective, about a 60 to 80 percent protection against colon cancer in rats.”

Word of Stoner’s findings soon spread, and several other OSU researchers are looking to fight cancer with berries. Dr. Christopher Weghorst and his research team began to test Stoner’s theory on hamsters with oral cancer.

“Dr. Stoner had shown black raspberries could deter esophageal and colon cancer,” Weghorst said. “We exposed the oral cavity of a hamster to tobacco smoke and carcinogens and gave them berries before, during and after exposing them to the carcinogens. The hamsters that were given the berries had significantly less tumors, about 44 percent.”

Weghorst wondered if the research was applicable to humans. Preliminary data from the last several years suggests that berries have a chemopreventive effect on extracts of human oral cancer cells. Weghorst advanced the study to patients, who received berry lozenges from the time of diagnosis through surgery. Before and after surgery, treatment of the same oral tissues from the same patients favored chemoprevention through gene modulation.

Despite all the research and success, doctors still are not exactly sure what causes the positive effects.

“Berries are a complex mixture, but one antioxidant that is a major player are the anthocyanins, basically what gives berries their dark color,” Weghorst said. “We do not know the specific compunds that are causing this. It’s probably not the result of one compound, it’s probably an additive effect.”

Expanding the Research:
Research on this topic has expanded to diverse lengths. Stoner is attempting to find similar effects in animals with strawberries. Dr. John Fromkes and Dr. Laura Kresty from OSU showed that berries reduce the size and spread of lesions in a form of esophageal cancer called Barrett’s esophagas. Dr. Susan Mallery from the department of dentistry is treating human pre-malignant lesions with a berry gel.

“The gel is causing a reduction or regression of the lesions of 50 to 60 percent of the patients in six weeks,” Stoner said.

Researchers are conducting berry trials in China for esophageal and colon cancer. Another study with a doctor from the Cleveland Clinic focuses on treating dangerous polyps that cause colon and rectal cancer. Stokes is also undertaking the biggest black raspberry trial in the nation with the help of Dr. Harry Schwartz from the University of Maryland.

“We’re constantly looking for black raspberries with higher bioactives,” Stokes said. “This is a conventional breeding process rather than genetic engineering. We’re not moving certain cells, we’re using the cells shown in the female plant.”

Randomized trials in the future might prove that certain berry compounds do prevent cancer, but for now OSU cancer researchers are recommending people eat about four ounces of black raspberries, blackberries or strawberries three to four times per week. The several different directions and treatment ideas that Stoner’s research has inspired is a significant accomplishment, a long way from what Stokes heard about berries 30 years ago.

“It doesn’t particularly surprise me,” Stokes said. “I had heard through word of mouth that other farmers were giving their calves with diarrhea black raspberries and it was helping. But I didn’t know how the compounds would work, or to what effect.”