A Grain of Hope for Prostate Cancer
July 11, 2001 -- Ground flaxseed -- a grain that was a dietary
staple in the 19th century -- may prevent the growth of prostate cancer and
speed the death of tumor cells when combined with a low-fat diet, according to
a small preliminary study.
Study author Wendy Demark-Wahnefried, PhD, tells WebMD that
flaxseed can affect levels of the male hormone testosterone, which may
influence the progression of prostate cancer. If confirmed by larger studies,
the findings suggest that flaxseed could serve as a nutritional complement or
alternative to using drugs or surgery to reduce testosterone in some men, she
In the study, 25 men with prostate cancer who were scheduled to
have their prostate removed consumed a low-fat, flaxseed-supplemented diet for
34 days. Each day, they ate three tablespoons of the ground flaxseed, either
sprinkled on cereal or mixed into other foods.
Following surgery, their tumors were compared with those taken
from men who were not involved in the study.
Denmark-Wahnefried found some exciting results. "[W]hen we
compared prostate tissue of men who consumed the diet prior to surgery, their
tumor cells were not [growing] as quickly and were undergoing death at a much
greater rate," she tells WebMD. She is associate research professor of
surgery at Duke University Medical Center in Durham, N.C.
Men on the flaxseed diet also had lower levels of cholesterol
and testosterone, and those with less aggressive disease showed a decrease in
PSA, the marker commonly used to screen for prostate cancer.
Flaxseed has fallen out of regular use in modern days because
it tends to spoil quickly. The grain is not often available in grocery markets
but can be found in health food stores, notes Denmark-Wahnefried.
The grain is rich in both lignan -- a fiber believed to help
regulate testosterone -- and omega-3 fatty acids, which have been shown to slow
cancer progression in animal studies, she adds.
Nonetheless, she cautions that the study is very preliminary
and requires far more research.
William Dahut, MD, is chief of the medical prostate cancer
clinic at the National Cancer Institute. He called the findings
"interesting" and said they support the already well-established
recommendations for a low-fat diet, in general. But whether flaxseed, as a
nutritional component itself, is affecting prostate tumors is difficult to
know, he says.
For those who want to add flaxseed to their diet,
Denmark-Wahnefried recommends ground flaxseed because the seed is naturally
pointy and tough and can perforate the stomach.
In the meantime, patients with prostate cancer who would be
candidates for hormonal therapy should still receive surgery or drugs that
"If you had prostate cancer and you were making a decision
about hormonal treatment," says Dahut, "you [would] use the real