"We are cautiously optimistic about these findings," said Wendy Demark-Wahnefried, Ph.D., associate professor, division of urology and senior author of the study that appears in the November 2002 issue of the journal Urology. "The amount of flaxseed given to each mouse was 5 percent of its total food intake, which would be a very difficult amount for humans to eat, but it does signal that we are on the right track and need to continue research in this area."
According to Demark-Wahnefried, planned clinical trials must be completed before it can be concluded that dietary flaxseed is a useful protective against prostate cancer in humans.
The research was sponsored by the National Institute of Aging, the National Cancer Institute and the Committee for Urologic Research Education and Development at Duke University Medical Center.
Clinical studies by other researchers have suggested that dietary fiber reduces cancer risk, and omega-3 fatty acids also have shown a protective benefit against cancer. Flaxseed is the richest plant source of omega-3 fatty acids and is high in fiber. Also, flaxseed is a source of lignan, a specific family of fiber-related compounds that appear to play a role in influencing both estrogen and testosterone metabolism. Since testosterone may be important in the progression of prostate cancer, lignan could help inhibit the growth and development of the disease.
In the Duke study, 135 mice genetically engineered to develop prostate cancer were divided into a control group and an experimental group. The experimental group received a regular mouse diet, but 5 percent of the diet was in
Contact: Amy Austell
Duke University Medical Center