|
"Since they were
first licensed nearly 50 years ago, birth control pills
containing estrogen have prevented some 200,000 cases of
ovarian cancer world-wide, estimate the authors of a
study published January 26 in The Lancet.
Further, in the absence of having taken oral
contraceptives, half of these women would have died of
the disease."
"The researchers showed
that oral contraceptives (OCs) continue to confer
protection for years - even decades - after women stop
using them. Thus, they surmise, "the number of ovarian
cancers prevented [will] rise over the next few decades"
to at least 30,000 each year."
"These figures emerge from
a comprehensive meta-analysis based on prospective and
case-control data from 45 epidemiological studies in 21
countries, mostly in Europe and the United States.
"These findings set a new standard in prevention for a
deadly cancer," wrote the editors of The
Lancet,
"and have important public health implications."
"The results showed that
women who had ever taken OCs were 27 percent less likely
to develop ovarian cancer. The studies included 23,257
women with ovarian cancer, 31 percent of whom
had taken OCs; of the 87,303 controls, 37 percent took OCs."
"Another feature of these
results is their uniformity. OCs seem to protect against
nearly all types of epithelial and nonepithelial tumors,
with the possible exception of mucinous ovarian cancer
(which accounted for only 12 percent of cases studied in
the meta-analysis). The Lancet editorial points
out that the results show "the benefits of oral
contraceptives are independent of the preparation
[estrogen dose], and vary little by ethnic origin,
parity, family history of breast cancer, body-mass
index, and use of hormone replacement therapy."
"Dr. Beral commented that
while OCs may pose a slight increased risk of breast and
cervical cancer, the effect is small and disappears once
the drugs are no longer being used, as contrasted with
the ongoing protective effect against ovarian cancer."
|
"Dr. Karlan added,
"Ovarian cancer remains a disease with a high mortality
due [mainly] to our inability to reliably diagnose it at
an early stage. Women are concerned about this risk."
She noted that it is important for women to be aware
that OCs reduce that risk when discussing their
contraceptive choices with their health care providers."
Source: The National Cancer Institute
http://www.cancer.gov/ncicancer
bulletin/NCI_Cancer_Bulletin_
020508/page2
|
High
Caffeine Intake During Pregnancy May Increase
Risk for Miscarriage |
"January 24, 2008 — A
high intake of caffeine during pregnancy increased the
risk for miscarriage, according to the results of a
population-based, prospective cohort study reported in
the January 21 Online First issue of the American
Journal of Obstetrics & Gynecology."
"Caffeine can readily
cross the placental barrier to the fetus; its clearance
is prolonged in pregnant women, and its metabolism rate
is low in the fetus because of low levels of enzymes,"
write Xiaoping Weng, PhD, from Kaiser Permanente in
Oakland, California, and colleagues. "Although numerous
studies on maternal caffeine consumption and the risk of
miscarriage have been published since the 1980s, the
effect of caffeine intake on the risk of miscarriage
remains controversial because of methodological
limitations. . . . The objective of this
population-based prospective study was to examine the
effect of maternal caffeine intake during pregnancy on
the risk of miscarriage, taking into account a number of
potential confounders, especially the impact of nausea
or vomiting during pregnancy."
"This observed
association was not significantly affected by nausea or
vomiting during pregnancy or by the change in intake
pattern of caffeine during pregnancy." |
"Our results
demonstrated that high doses of caffeine intake
during pregnancy increase the risk of miscarriage,
independent of pregnancy-related symptoms," the
study authors write. "We provided new evidence that
the observed association was not likely the result
of confounding by the pregnancy-related symptoms of
nausea, vomiting, and aversion to caffeine
consumption. Therefore, it may be prudent to stop or
reduce caffeine intake during pregnancy."
Summary:
"Caffeine has been
extensively studied as a possible deleterious substance
during pregnancy. It readily crosses the placental
barrier, and clearance of caffeine is slower in pregnant
vs nonpregnant women. The fetus has low levels of
enzymes which break down caffeine, so fetal metabolism
of caffeine is delayed."
"Some research has
suggested that caffeine can reduce intervillous blood
flow, but data regarding the role of caffeine in
promoting miscarriage are limited because of questions
regarding the methodology of this research. The current
study recruited women early in pregnancy and adjusted
for possible confounders in an attempt to address these
methodologic flaws."
Laurie Barclay M.D.
Charles Vega M.D.
Source:
Medscape Medical News |