Could An Aspirin A Day Help Keep Prostate Cancer Away?
ROCHESTER, MINN. -- A Mayo Clinic study suggests
that regular use of aspirin, ibuprofen and other nonsteroidal
anti-inflammatory drugs (NSAIDs) may help protect against prostate cancer,
the second leading cause of cancer death among men in the United States.
The study found that men age 60 and older who used NSAIDs daily reduced
their risk of prostate cancer by as much as 60 percent. The study also
suggested that the beneficial effect may increase with age.
The findings of this study are published in the March issue of Mayo
Clinic Proceedings.
The 1,362 Caucasian men in this study were followed for an average of
five and one-half years. Of the 569 men who reported using NSAIDs daily, 23
developed prostate cancer, compared with 68 of 793 men in the same study who
did not use NSAIDs daily and developed the disease.
"These numbers mean the proportion of men who used NSAIDs daily and
developed prostate cancer was about one-half that of men who did not use
NSAIDs daily -- four percent compared to nine percent," says Rosebud
Roberts, M.D., a Mayo Clinic epidemiologist and lead researcher on the
study.
"Further, the association between NSAIDs and prostate cancer appears to
be stronger in older men," says Dr. Roberts. "The risk of prostate cancer
among NSAID users was 12 percent lower in men age 50 to 59 years, 60 percent
lower in men 60 to 69 years, and 83 percent lower in men age 70 to 79 years
compared to men in those same age groups who did not use NSAIDs daily."
The results may mean good news for men, but Dr. Roberts cautions that
more research needs to be done.
"Although our findings provide important information that NSAIDs may
protect against prostate cancer, they are not conclusive," says Dr. Roberts.
"More research needs to be done to show that the results we saw in our
study were not unique to our study but can be confirmed in other similar
studies," she said. "We also need to determine the duration and dosage use
that provides protection against prostate cancer and to better understand
the biologic mechanisms underlying the association between NSAIDs and
prostate cancer."
Dr. Roberts added that since the study included only Caucasian men in
southeastern Minnesota, it’s not known whether the findings apply to men of
all races.
"African American men have the highest risk of prostate cancer," said Dr.
Roberts. We need to complete additional research to determine if these
findings are applicable to them."
Should a man age 50 or older take an aspirin, ibuprofen or another NSAID
every day based on the study’s findings?
"Men should discuss the study with their doctors and follow their
doctor’s advice, but they should not start taking NSAIDs solely on the basis
of our findings," says Dr. Roberts.
"While our findings complement previous studies that NSAIDs help protect
against breast and colon cancers, and possibly against prostate cancer,
there are also negative side effects of NSAIDs that need to be considered
and monitored in people who take NSAIDs on a daily basis," she says.
About 189,000 men in the United States will be diagnosed with prostate
cancer this year. About 30,200 men will die of the disease.
This study was part of a larger Mayo Clinic study that monitored lower
urinary tract symptoms in 2,115 men from Olmsted County of southeastern
Minnesota. The men ranged in age from 40 to79 years at the onset of the
study in 1990.
The findings about the association between prostate cancer and NSAIDs are
based on information obtained from a subset of 1,362 men in the study who
were age 50 years and older in 1990. These men reported using 40 different
prescription and over-the-counter NSAIDs at the beginning of the study and
during follow-up.
http://www.sciencedaily.com/releases/2002/03/020313075214.htm
Second Thoughts on Mercury in Fish
By MARIAN BURROS
New York Times
AS
the Food and Drug Administration overly sensitive to the commercial
interests of the tuna industry when it established guidelines on fish
consumption and mercury contamination? Documents released this month by a
watchdog group are raising that question as well as others about the
decision-making that went into the agency's warning to pregnant women about
which fish to avoid to reduce the risk of harming their fetuses.
The documents, obtained under the Freedom of Information Act by the
Environmental Working Group, include 1,000 pages of transcripts and other
reports related to meetings and discussions that led to the January 2001
advisory that pregnant women not eat fish like mackerel and swordfish. Among
them were three meetings the F.D.A. had with the U.S. Tuna Foundation,
Chicken of the Sea, Starkist, Bumble Bee and the National Food Processors
Association.
The industry meetings in themselves were not unusual. However, the
Environmental Working Group and at least one member of Congress are
questioning whether undue weight was given to the industry's position, while
the opinions of others, including consumer focus groups, were discounted.
Earlier this month the F.D.A. itself acknowledged a need to revisit its
own recommendations. In a rare move, just a year after its list was
released, the agency announced a meeting of its Foods Advisory Committee to
review mercury in seafood.
"We are going back because the Environmental Working Group report had
some things in there that went to the process, and we wanted to be sure
there isn't any question about that," said Joseph A. Levitt, director of the
agency's Center for Food Safety and Applied Nutrition.
The F.D.A.'s advisory warned pregnant women not to eat swordfish, king
mackerel, shark and tilefish because of high levels of mercury contamination
that could cause neurological defects or delays in mental development in
their children. Mysteriously absent from the list was one of the most
significant sources of mercury in the American diet, tuna.
The F.D.A. said at the time it had identified those species of most
concern to pregnant women, based on scientific evidence, the fact that
Americans don't eat dangerous levels of tuna and a desire not to confuse
women.
"We feel we have evaluated the science in an appropriate way, and our
advisory is right on target," Michael Bolger, director of the division of
risk assessment of the Center for Food Safety and Applied Nutrition, said
last May. Besides, Mr. Bolger added, if given too much information — like
guidelines distinguishing between safe and unsafe fish and those to be eaten
infrequently — women would stop eating all fish.
He based this opinion, he said, on the responses of three focus groups to
statements that included the following: "Tuna steaks can be eaten three
times a month. You can eat one and a half six-ounce cans of tuna every week
with no problems."
In a document released at the time, the F.D.A. reiterated its reasoning:
"The major points gleaned from the focus groups were to keep the message
simple and direct," the report said, adding that if pregnant women were told
to limit consumption, they would interpret it to mean "do not consume."
The documents obtained by the Environmental Working Group show, however,
that women were far more savvy than that. After being presented with
examples of detailed health advisories that included specific advice about
tuna, 30 out of 37 comments indicated that the respondents would still eat
fish but avoid those with high mercury levels, many specifically mentioning
that they would continue to eat tuna but in limited amounts. Only seven
individual remarks in the transcripts support the F.D.A. assertion that
limiting consumption was equated with not eating any fish. More typical was
this response from one participant: "My advice would be not to eat the
mackerel, the shark and the swordfish. But I would also put in a note; you
should limit your intake of the tuna and then, you know, eat the rest of the
fish in moderation."
Mr. Levitt asserted: "We have different conclusions on what the focus
groups said. When we said limit, they heard avoid."
Meanwhile, the F.D.A. held three meetings with industry representatives,
the documents show. The industry arguments included a claim that tuna
consumption "is not as great as anecdotal observations would indicate" — a
position that is at odds with the industry's eagerness to keep canned tuna
off the advisory list, as well as with tuna's place as the best-selling
fish, accounting for a third of all seafood sales in the United States.
Nevertheless, the F.D.A. agreed. The two-page rationale, as they called it,
released in February 2001, said that those who do eat canned tuna consume,
at most, only about seven ounces a week, or not enough to pose a risk of
mercury contamination.
Following that reasoning, why advise pregnant women not to eat tilefish
or shark, which are consumed seldom, if at all?
"We'll never know exactly how much influence industry had in the
process," said Jane Houlihan, vice president for research at the
Environmental Working Group. "What we do know is that tuna was in the draft
advisories and wasn't in the final advisory. The F.D.A. ignored the advice
from every other group they called in. And we know the F.D.A.'s public
excuse for why they dropped tuna from the advisory is untrue. Their excuse
is that people don't eat enough canned tuna, so there is no need for an
advisory."
Randi Thomas, a spokeswoman for the U.S. Tuna Foundation, the trade
association representing the domestic canned tuna industry, acknowledged her
association's influence. "I certainly hope we had an impact," she said,
"because we showed them the nutritional benefits of tuna."
Critics of the advisory say the F.D.A. based its recommendations on
outdated research about safe mercury levels in the blood, with the limit
eight times higher than was deemed safe by both the National Academy of
Sciences and the Environmental Protection Agency. If the F.D.A. followed the
National Academy's standard, it would tell pregnant women not to eat any
tuna steaks at all, and canned tuna only once a month.
Meanwhile, the Centers for Disease Control and Prevention has data
showing that 10 to 15 percent of American women of child-bearing age —
600,000 — have mercury in their blood at levels higher than the E.P.A.'s
safe level, putting their children at risk of harm.
Scientists are still assessing the impact of mercury on fetuses. Some
studies done in other countries have found that mothers who ate fish with
high levels of mercury bore children with scores on intelligence tests 7 to
8 points lower on a 100-point scale. Two studies linked neurotoxic effects
like delays in mental development to chronic fetal exposure to high levels
of mercury from fish.
While the F.D.A. reviews its advisory, Congress also may take action.
Representative Frank Pallone Jr., a New Jersey Democrat, questioned the
agency's motives last week and asked the inspector general of Health and
Human Services to investigate. Mr. Pallone has introduced legislation that
would require the F.D.A. to test mercury levels in fish, a program abandoned
in 1998, and to set a safer threshold level for it in seafood.
http://www.nytimes.com/2002/03/13/dining/13WELL.html
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