Fruits and vegetables have long been known to help reduce the risk of certain cancers. Based on prior research, the American Cancer Society recommends eating five servings of fruits and vegetables daily.
In the first study, Ohio State University researchers found black raspberries may protect against esophageal cancer by reducing the oxidative stress that results from Barrett's esophagus, a precancerous condition usually caused by gastroesophageal reflux disease. The esophagus is a long tube that connects the throat to the stomach. Reflux disease causes stomach acid to continually splash back up into the esophagus.
People with Barrett's esophagus typically are 30 to 40 times more likely to develop esophageal cancer, which has a poor five-year survival rate of 15 percent.
Black raspberries previously have been shown to reduce the risk of oral, esophageal and colon cancer in animal models, according to the researchers, who called for further study in humans.
In other research presented at the meeting, broccoli sprouts and cruciferous vegetables both showed promise in the fight against bladder cancer.
A second team at the institute found that people who ate three or more servings of raw, cruciferous vegetables per month reduced their risk of bladder cancer by 40 percent. Cruciferous vegetables include broccoli, cabbage and cauliflower.
The team analyzed the dietary habits of 275 people with early bladder cancer and 825 people who were cancer-free. The researchers specifically asked how many servings of raw or cooked cruciferous vegetables they ate before their diagnosis and whether they smoked.
Analysis of the data showed that the more raw, cruciferous vegetables people ate, the lower their risk of bladder cancer. In comparison to people who smoked and ate fewer than three servings of raw vegetables a day, nonsmokers eating at least three servings of cruciferous vegetables daily were 73 percent less likely to develop bladder cancer.
