D.
Sat, Jun-23-07, 06:16
Research in mice suggests that a diet high in omega-3 fatty
acids found in fish oil and certain types of fish could
potentially improve the prognosis of men who are genetically
prone to develop prostate cancer. The research is reported
online by the Journal of Clinical Investigation and will
appear in the July 2 print issue. Here's more:
"This study clearly shows that diet can tip the balance toward
a good or a bad outcome," said senior researcher Yong Q. Chen,
Ph.D., from Wake Forest University School of Medicine. "It's
possible that a change in diet could mean the difference
between dying from the disease and surviving with it."
In mice that were engineered with a genetic defect that caused
prostate cancer, a diet high in omega-3 fatty acids beginning
at birth reduced tumor growth, slowed disease progression and
increased survival. Prostate cancer is the most frequently
diagnosed cancer and is a leading cause of death in men in the
United States. Population studies have suggested that
consumption of fish or fish oil reduces prostate cancer
incidence. However, these investigations have been hampered by
the difficulty people have in accurately reporting their
dietary intake.
The goal of the current study was to explore gene-diet
interactions in prostate cancer. It involved mice that were
engineered with a genetic defect - they lacked a tumor
suppressor gene and spontaneously developed prostate cancer.
This gene (Pten) is absent in 60 to 70 percent of metastatic
cancers in humans.
The engineered mice and "wild-type" (or non-engineered) mice
were fed varying levels of omega-3 and omega-6 polyunsaturated
fatty acids (PUFAs). Both are "essential" fatty acids, which
means the body needs them for proper cell function but cannot
produce them. Many vegetable oils contain omega-6 PUFA. Fish
like mackerel, lake trout, herring, sardines, albacore tuna
and salmon are high in omega-3 fatty acids.
Nutritionists recommend that people consume equal proportions
of omega-3 and omega-6 PUFA. However, in current western
diets, the proportion of omega-6 to omega-3 is between 30 and
50 to one.
The mice were fed either a diet high in omega-3 (ratio of
omega-6 to omega-3 was 1:1) a diet low in omega 3 (ratio
omega-6 to omega-3 was
20:1), or a diet high in omega-6 (ratio of omega-6 to
omega-3 was
20:2). The scientists compared survival rates and weighed the
animals' prostates to measure tumor progression.
Mice with the tumor suppressor gene remained free of tumors
and had 100 percent survival, regardless of diet. In mice with
the gene defect, survival was 60 percent in animals on the
high omega-3 diet, 10 percent in those on the low omega-3 diet
and 0 percent in those on the high omega-6 diet.
"This suggests that if you have good genes, it may not matter
too much what you eat," said Chen, a professor of cancer
biology. "But if you have a gene that makes you susceptible to
prostate cancer, your diet can tip the balance. Our data
demonstrate the importance of gene-diet interactions, and that
genetic cancer risk can be modified favorable by omega-3
PUFA." Chen said dietary changes may be particularly
beneficial in people prone to prostate cancer because the
disease is usually diagnosed in older men and the tumors are
slow-growing. It's possible that eating a high omega-3 diet
could delay tumor development or progression long enough for
the man to live out his natural lifespan with prostate cancer.
The authors cautioned that the effects were obtained with the
omega-3s found in fish oil and that omega-3s from flaxseed oil
and other plants may not provide the same results.
Dave (Google "Sham vs. Wham: The Health Insider" for
original text)
acids found in fish oil and certain types of fish could
potentially improve the prognosis of men who are genetically
prone to develop prostate cancer. The research is reported
online by the Journal of Clinical Investigation and will
appear in the July 2 print issue. Here's more:
"This study clearly shows that diet can tip the balance toward
a good or a bad outcome," said senior researcher Yong Q. Chen,
Ph.D., from Wake Forest University School of Medicine. "It's
possible that a change in diet could mean the difference
between dying from the disease and surviving with it."
In mice that were engineered with a genetic defect that caused
prostate cancer, a diet high in omega-3 fatty acids beginning
at birth reduced tumor growth, slowed disease progression and
increased survival. Prostate cancer is the most frequently
diagnosed cancer and is a leading cause of death in men in the
United States. Population studies have suggested that
consumption of fish or fish oil reduces prostate cancer
incidence. However, these investigations have been hampered by
the difficulty people have in accurately reporting their
dietary intake.
The goal of the current study was to explore gene-diet
interactions in prostate cancer. It involved mice that were
engineered with a genetic defect - they lacked a tumor
suppressor gene and spontaneously developed prostate cancer.
This gene (Pten) is absent in 60 to 70 percent of metastatic
cancers in humans.
The engineered mice and "wild-type" (or non-engineered) mice
were fed varying levels of omega-3 and omega-6 polyunsaturated
fatty acids (PUFAs). Both are "essential" fatty acids, which
means the body needs them for proper cell function but cannot
produce them. Many vegetable oils contain omega-6 PUFA. Fish
like mackerel, lake trout, herring, sardines, albacore tuna
and salmon are high in omega-3 fatty acids.
Nutritionists recommend that people consume equal proportions
of omega-3 and omega-6 PUFA. However, in current western
diets, the proportion of omega-6 to omega-3 is between 30 and
50 to one.
The mice were fed either a diet high in omega-3 (ratio of
omega-6 to omega-3 was 1:1) a diet low in omega 3 (ratio
omega-6 to omega-3 was
20:1), or a diet high in omega-6 (ratio of omega-6 to
omega-3 was
20:2). The scientists compared survival rates and weighed the
animals' prostates to measure tumor progression.
Mice with the tumor suppressor gene remained free of tumors
and had 100 percent survival, regardless of diet. In mice with
the gene defect, survival was 60 percent in animals on the
high omega-3 diet, 10 percent in those on the low omega-3 diet
and 0 percent in those on the high omega-6 diet.
"This suggests that if you have good genes, it may not matter
too much what you eat," said Chen, a professor of cancer
biology. "But if you have a gene that makes you susceptible to
prostate cancer, your diet can tip the balance. Our data
demonstrate the importance of gene-diet interactions, and that
genetic cancer risk can be modified favorable by omega-3
PUFA." Chen said dietary changes may be particularly
beneficial in people prone to prostate cancer because the
disease is usually diagnosed in older men and the tumors are
slow-growing. It's possible that eating a high omega-3 diet
could delay tumor development or progression long enough for
the man to live out his natural lifespan with prostate cancer.
The authors cautioned that the effects were obtained with the
omega-3s found in fish oil and that omega-3s from flaxseed oil
and other plants may not provide the same results.
Dave (Google "Sham vs. Wham: The Health Insider" for
original text)