Blackberries, Broccoli Sprouts Battle Cancer

Blackberries, Broccoli Sprouts Battle Cancer
THURSDAY, Dec. 6 (HealthDay News) -- Your local farmer's marketmight hold the key to cancer prevention, since new research shows thatblack raspberries, broccoli sprouts and some raw vegetables reduce therisk of esophageal and bladder cancers.
Data from three studies on the subject was presented Thursday at theAmerican Association for Cancer Research's Sixth Annual InternationalConference on Frontiers in Cancer Prevention, in Philadelphia.
Fruits and vegetables have long been known to help reduce the risk ofcertain cancers. Based on prior research, the American Cancer Societyrecommends eating five servings of fruits and vegetables daily.
In the first study, Ohio State University researchers found blackraspberries may protect against esophageal cancer by reducing theoxidative stress that results from Barrett's esophagus, a precancerouscondition usually caused by gastroesophageal reflux disease. The esophagusis a long tube that connects the throat to the stomach. Reflux diseasecauses stomach acid to continually splash back up into the esophagus.
"Specifically in the case of Barrett's patients, reflux of the stomachand bile acid contribute to ongoing oxidative damage. Thus, our hypothesisis that feeding a food that is high in potential protective constituents,such as antioxidants, vitamins, minerals and other phytochemicals, mayhelp restore the oxidative balance," lead researcher Laura Krestysaid.
People with Barrett's esophagus typically are 30 to 40 times morelikely to develop esophageal cancer, which has a poor five-year survivalrate of 15 percent.
The team gave 32 grams to 45 grams of black raspberries daily for sixmonths to 20 patients with Barrett's esophagus. They analyzed changes inblood, urine and tissue before, during and after the treatment, and foundlower levels of some of the chemical markers of oxidative stress in bothurine and tissue samples.
Black raspberries previously have been shown to reduce the risk oforal, esophageal and colon cancer in animal models, according to theresearchers, who called for further study in humans.
Dietitian Wendy Demark-Wahnefried, a professor of behavioral science atM.D. Anderson Cancer Center at the University of Texas in Houston, saidshe would feel comfortable advising people with Barrett's to eat blackraspberries. "It couldn't hurt," she said, but added that further studiesneed to find out if the berries really do prevent cancer.
In other research presented at the meeting, broccoli sprouts andcruciferous vegetables both showed promise in the fight against bladdercancer, according to two separate teams from the Roswell Park CancerInstitute in Buffalo, N.Y.
Using a rat model, a team lead by Dr. Yuesheng Zhang, a professor ofoncology, demonstrated that a broccoli sprout extract reduced bladdercancer in rats by 70 percent.
"Our present study shows that broccoli sprout extracts fed to rats inthe diet inhibits bladder cancer development induced by a carcinogen. Wedon't yet know if the extracts inhibit the growth of a existing bladdercancer," said Zhang, who explained that broccoli sprouts are a rich sourceof a well-known cancer preventive agent known as sulforaphane.
"We next plan to find out if broccoli sprout extracts can fight bladdercancer in humans," Zhang noted.
A second team at the institute found that people who ate three or moreservings of raw, cruciferous vegetables per month reduced their risk ofbladder cancer by 40 percent. Cruciferous vegetables include broccoli,cabbage and cauliflower.
The team analyzed the dietary habits of 275 people with early bladdercancer and 825 people who were cancer-free. The researchers specificallyasked how many servings of raw or cooked cruciferous vegetables they atebefore their diagnosis and whether they smoked.
Analysis of the data showed that the more raw, cruciferous vegetablespeople ate, the lower their risk of bladder cancer. In comparison topeople who smoked and ate fewer than three servings of raw vegetables aday, nonsmokers eating at least three servings of cruciferous vegetablesdaily were 73 percent less likely to develop bladder cancer.
"In our study, we do find intake of raw cruciferous vegetables showedrisk reduction of bladder cancer in smokers, and even the heaviersmokers," said lead researcher Li Tang.
The researchers stressed that the benefits are derived from rawcruciferous vegetables, giving cole slaw the edge over cabbage soup whenit comes to cancer prevention.
"This confirms that there are a variety of compounds within fruits andvegetables that contribute to reducing the risk of cancer. Research likethese studies contribute to our knowledge about what the impact ofspecific nutrients may be on specific types of cancer," said ColleenDoyle, director of nutrition and physical activity for the American CancerSociety. "Cooking leaches out some nutrients but makes others moreabsorbable. Until we know more in this regard, the bottom-line message forconsumers is eat at least five servings of fruits and vegetables each day,raw and/or lightly cooked. Focus on those with the most color, since, ingeneral, fruit and vegetables with the most color have the mostcancer-fighting antioxidants and phytochemicals."
"Surveys we've done indicate many people don't think they have controlover their cancer risk, but studies clearly indicate they do. For themajority of people who don't smoke, watching their weight, being moreactive and eating a healthy diet are the most important ways to reducecancer risk," Doyle said.