Olestra Cause Digestive Problems?
January 14, 1998
Are digestive problems the price you must
pay for lower fat and calories? A new Johns Hopkins study
The study examined olestra, a fat substitute approved
last year for use in snack foods like potato, corn and
tortilla chips. In some studies, people reported
abdominal cramps and other unpleasant effects after
eating products made with olestra. But those trials asked
people to consume the stuff at every meal for nearly two
full months. Johns Hopkins director of digestive diseases
Dr. Lawrence Cheskin wanted to test olestra in the real
world. So he asked 1,100 movie-goers to munch a bag of
potato chips while they watched a favorite flick. Half of
the bags had olestra and the others had ordinary fat.
"In this type of setting, which is a typical setting
for eating potato chips at a single sitting--as much or
as little as you want to eat--there does not seem to be
any excess GI effects from olestra compared to regular
potato chips," explains Cheskin.
Sixteen percent of those who ate the olestra-laden chips
did report some gastro-intestinal discomfort later. But
the number was even higher for those who crunched the
regular kind, leaving researchers to conclude that in
normal helpings, olestra doesn't cause any problems.
Cell Lifespan Extended
January 14, 1998
For the first time, researchers have
confirmed that the "clock" thought to control
aging in human cells does indeed dictate that process.
What's more, they have found a way to circumvent the
process - extending the lifespan of normal, healthy human
cells, according to a report in Science.
The finding has "profound" implications for the
study of cancer, which may use the same process to escape
the aging process, according to an editorial accompanying
And it may lead to treatment for human disease caused by
worn out cells, such as macular degeneration - the
leading cause of blindness in those over 65.
"This research raises the possibility that we could
take a patient's own cells, rejuvenate them, then modify
the cells as needed and give them back to the patient to
treat a variety of genetic and other diseases," said
senior investigator Dr. Woodring E. Wright in a statement
released by the University of Texas Southwestern Medical
Center at Dallas. "The potential long-term
applications are simply staggering," said Wright, a
professor of cell biology and neuroscience. The study was
a collaborative effort involving researchers at the
medical center and at Geron Corp., in Menlo Park,
Most cells will divide roughly 50 times in the laboratory
before entering a resting state known as senescence, a
process that also occurs in the body. For more than a
decade, researchers have suspected that telomeres,
sections of DNA at the tips of chromosomes, control that
Like minutes ticking on a clock, a piece of telomere is
lost each time the cell divides. But some cells contain
an enzyme, called telomerase, that can re-build the
telomere after cell division.
In the new study, the gene for telomerase was inserted
inside three types of cells that don't normally carry the
enzyme - retinal pigment epithelial cells, foreskin
fibroblasts, and the vascular endothelial cells - or
those lining blood vessels. In contrast with cultured
cells that have telomere shortening, the genetically
engineered cells continued to vigorously divide and have
The treated cell population doubled at least 20 more
times than normal and continues to grow, according to the
report. The new findings confirm that telomeres are the
"clock" that keeps cells from growing out of
control, according to an editorial by Titia de Lange, of
the Laboratory for Cell Biology and Genetics at The
Rockefeller University in New York. And that mechanism
has all "the makings of a powerful tumor suppressor
system," de Lange wrote.
"The results should strengthen the determination of
those who are searching for telomerase inhibitors as
potential anti-cancer agents."
Sydney Flu Virus Hits US
January 14, 1998
A flu strain found in Australia last year
has found its way to the US - and health experts are not
certain how much protection this year's flu vaccine
offers against it.
The Type A Sydney flu strain (A/Sydney) has been found in
40% of cases tested by the US Centers for Disease Control
and Prevention (CDC) in Atlanta since October. This
particular flu strain was not included in the vaccine
designed to cover the 1997-1998 flu season.
But the current flu vaccine does offer protection against
a close relative of A/Sydney, the Type A Wuhan (or
Nanchang) influenza virus - and so may also offer
"partial" protection against the Sydney strain,
according to a CDC expert. Both of the viruses are Type A
H3N2 viruses. So far this season, the Wuhan strain has
been found in 60% of flu samples analyzed at the CDC.
"Years when the A-H3 viruses are the predominant
circulating type... are when disease tends to be more
severe in high-risk groups in terms of hospitalization
and fatalities," said Dr. Stephen Ostroff, associate
director of the National Center for Infectious Diseases
at the CDC in an interview with Reuters.
However, it is still relatively early in this year's flu
season, too early to tell if the A/Sydney strain will
make an impact on flu deaths this year, added Ostroff.
Ostroff encourages people - especially those in high-risk
groups such as those over 65 and those with chronic lung
diseases - to be vaccinated against the flu.
"At least, (this year's flu vaccine) offers partial
protection against A/Sydney. At best, it's protection
could be quite good," he explained.
The Sydney flu virus was identified in Australia last
June. According to a report in Tuesday's USA Today, this
strain of flu is believed to have arrived in the US in
September when an Australian tourist took a New England
cruise, and appears to have infected other people on
board the ship.
Cases of A/Sydney influenza have been reported in
California and New York.
Brain Blood Flow During Heavy Snoring
January 9, 1998
The underlying mechanism of increased
stroke risk associated with heavy snoring most likely
involves an episodic reduction in blood flow in the
middle cerebral artery (MCA) during the non-rapid eye
movement (NREM) stage of sleep. That's according to a
team of US and German researchers, reporting in the
January issue of Stroke.
Lead investigator, Dr. Nikolaus Netzer of Case Western
Reserve University in Cleveland, Ohio, and colleagues
evaluated 11 men and 1 woman with a median age of 54
years who were self- reported "heavy snorers."
The subjects were selected because of their likelihood of
having sleep- disordered breathing.
The researchers monitored the subjects using continuous
Doppler sonography during sleep for changes in cerebral
blood flow resulting from an episode of apnea (where
breathing stops for a short period during sleep) or
hypopnea (where breathing becomes more shallow and/or
slower). They observed significant declines in blood flow
during 76% of the obstructive hypopnea episodes and
during 80% of the obstructive apneas. However,
significant declines were apparent in only 14% of the
episodes of central apnea.
"While duration of events was not significantly
different, MCA blood flow reductions were associated only
with the duration of the obstructive hypopneas... and not
with the duration of central... or obstructive...
apneas." Similarly, reductions in arterial oxygen
saturation corresponded to reduced blood flow during
obstructive hypopnea episodes only.
"Our hypothesis is that the negative thoracic
(internal chest)... pressure causes a reduction in blood
flow in the middle cerebral artery that may lead to
stroke," Netzer commented in an American Heart
Association press release.
Based on these findings, Netzer's team suggests
"...that obstructive hypopneas, the physiological
correlate for heavy snoring, have at least as great or an
even greater significance than either central or
obstructive apneas." The next step of the research
will be to determine the relative risk for stroke by
specific type of breathing-related sleep disorder.
SOURCE: Stroke (1998;29:87-93)
Lowers Blood Pressure
January 16, 1998
Potassium, either in foods or in
supplements, can lower blood pressure in people with low
daily intake of the mineral, according to a study in the
current issue of the journal Hypertension.
Lead author Dr. Frank Sacks, of the Harvard School of
Public Health in Boston, believes that individuals
concerned about their blood pressure "should eat a
diet high in potassium or take supplements."
Potassium-rich foods include fruits such as bananas and
oranges, as well as leafy green vegetables.
The researchers studied the effects of various mineral
supplements on the blood pressure of 300 middle-aged
women with normal, healthy blood pressures. Each of the
women (who were part of the larger, ongoing Nurses'
Health Study) also had low levels of daily potassium
intake relative to the general population.
The women were placed on a four-month regimen of daily
supplements of either potassium (1600 milligrams/day),
calcium (1200 mg/day), magnesium (336 mg/day), a
combination of all three supplements, or placebo.
The researchers discovered that, "compared with the
placebo group, blood pressure decreased significantly...
in the potassium group by 2.0 mm Hg for systolic pressure
(the first number in a blood pressure reading)... and by
1.7 mm Hg for diastolic pressure (the second
However, they found "no significant (blood pressure)
changes in the magnesium or calcium groups."
And the researchers found that supplement regimens made
up of combinations of the three minerals had much less of
an impact on blood pressure than supplementation with
potassium alone. The authors say this suggests that
"magnesium and calcium, ineffective as single
supplements, could actually interfere with the blood
pressure-lowering action of potassium."
They also believe that potassium supplementation may not
significantly lower blood pressure in those individuals
who already have an average or high daily dietary intake
of the mineral.
Sacks said that although the study focused on women with
normal blood pressure "...previous studies have
shown that potassium in people with high blood pressure
has a greater effect of lowering blood pressure by 4 to 5
January 14, 1998
Wondering how to fit exercise into your
day? What about a 30-minute workout at lunch?
Spend the first 20 minutes either on the
Lifecycle or the treadmill (at a three to five percent
incline, walking three to four miles per hour) is a good
Finish off your workout using the weight equipment,
including upper body exercises -- especially triceps
(back of arms), shoulders, chest, and back.
For your lower body, concentrate on the quads (front of
thighs), hamstrings (back of thighs), along with gluteal
(butt) and inner thigh exercises. Spend a few minutes
doing abdominal exercises.
You may not be able to fit all of this into your
30-minute routine, but be organized and vary the
exercises so you hit each area at least once a week.
Good luck and don't give up too soon. It's hard to say
how long it will take to see your results, but you are on
the right track and you just need to hang in there.
Linked To Birth Defects
January 16, 1998
Dextromethorphan, an ingredient in some
cough medicines, has been shown to cause birth defects
and fetal death in chicken embryos exposed to
concentrations relative to those typically taken by
humans, according to a paper in the January issue of
Dr. Thomas H. Rosenquist and colleagues at the University
of Nebraska gave chicken embryos various doses (5, 50 or
500 nanomoles/deciliter) of dextromethorphan over three
consecutive days. More than half of those given the
highest dose died, while about one-eighth of the
survivors developed congenital defects including
"...neural tube defects such as spina bifida, facial
defects similar to cleft palate, as well as cranial
defects," a University press release explains.
"Dextromethorphan was also highly lethal at 50
nmol/embryo/d," the team writes in the Pediatric
According to Rosenquist, these findings add weight to
recently reported findings from the Baltimore-Washington
Infant Study in which a history of cough medicine use
emerged as a risk factor for congenital malformations.
"We found that dextromethorphan causes defects so
early in the development of the embryo that in many cases
the woman wouldn't even know she is pregnant,"
Rosenquist said in the statement. "We feel that a
single dose is capable of causing a birth defect and
that, ultimately, it could be the cause for a woman to
have a miscarriage."
Dextromethorphan suppresses cough by acting on receptors
in the adult central nervous system. But in embryos, the
drug appears to "knock out" the receptors, thus
leading to the defects.
Further study is needed, but in the meantime, Rosenquist
suggests that pregnant women be advised not to use
dextromethorphan-containing cough medicine.
"Although we used chicken embryos in our study,
modern molecular biology shows that the same genes
regulate early development in virtually all species -
from insects to worms to humans," said Rosenquist.
"Based on this, it can be predicted that the effects
dextromethorphan had on the chicken embryos also would
occur in human babies."
SOURCE: Pediatric Research
Warns Against Diet Supplements To Prevent Cancer
January 13, 1998
The World Health Organization (WHO)
cautioned against using dietary supplements to prevent
cancer, saying that eating fresh fruits and vegetables
remained the preferred defense against the disease.
In a statement released here, the WHO warned in
particular against the promotion of carotenoid pills as a
"Fresh fruits and vegetables ... remain the first
line of defense against the disease," the statement
Published data from several clinical trials involving
carotenoids and beta-carotene showed that "in none
of these trials did the drug have a significant
preventive effect," the statement said.
"Moreover, when given to regularly smoking
volunteers, it was shown to increase the risk of lung
cancer and mortality from cardiovascular diseases,"
it quoted Dr. Harri Vainio as saying.
Vainio heads the chemoprevention unit at the WHO's
International Agency for Research on Cancer (IARC) in
Lyon, France, where a working group of 23 scientists from
10 countries held a conference in December 1997.
"Our group came to the conclusion that ... none of
these substances should be promoted to the general
population as a tumor-preventive treatment," Vainio
"It appears at present that cancer prevention by
fresh fruits and vegetables remains more effective than
taking one or several of their constituents as dietary
Call Tobacco Deadlier Than Air Pollution
January 26, 1998
Smoking is vastly more damaging to
peoples' lungs than air pollution, medical specialists
said, criticizing the media for focusing too much on the
"Some 60,000 people each year in France die 15 years
too early as a result of smoking," Bertrand
Dautzenberg, a lung specialist at a Paris hospital, said
at a conference in this southern French city.
"A person who smokes a packet of cigarettes a day
has one chance in two of dying from an illness related to
tobacco," he said.
"Air pollution every year aggravates the cases of
500 to 1,000 people who are already stricken with serious
lung diseases and condemned in the short term," he
"When these very sick patients are regularly
submitted to air pollution, life expectancy is diminished
by four weeks," he said.
Jean-Claude Puget of the Center for Treatment of
Respiratory Illnesses in Paris said: "Today people
are certain pollution kills but it's just media
manipulation because the dangers of pollution are
infinitely less than those of tobacco."
Jean-Paul Janssens, the head doctor at the Respiratory
Rehabilitation Center in Rolle, Switzerland, said there
was a worrisome resurgence in smokers among adolescents
and young women between 15 to 20 years old.
Some 300,000 adolescents between 14 and 16 years old join
the ranks of smokers in France each year, he said.
Young people were easily influenced by cigarette
"Our role can only be to inform and channel the
media assault because we will never have the means to
counter those of the tobacco industry," Janssens
Dautzenberg said "smoking also means 48 billion
francs (eight billion dollars) enter (French) state
coffers every year. We must therefore fight the finance
ministry to launch anti- tobacco campaigns."
React Differently To Forced Sex
January 26, 1998
Under extreme psychological stress,
adolescent girls typically turn to
"internalizing" behaviors such as bulimia or
withdrawal, while boys tend to "act out" in
violent, aggressive behaviors. But a new study finds that
teenagers who are forced or pressured to engage in sexual
intercourse deviate from this pattern, with girls turning
to violence and boys internalizing their psychological
"Behaviors differed among sexually active male and
female adolescents reporting being forced or pressured to
have sex," according to research appearing in the
current issue of the journal Archives of Pediatrics and
In 1995, researchers led by Dr. Lydia Shrier of Harvard
Medical School in Boston, Massachusetts, sent detailed
psychological and behavioral questionnaires to nearly
22,000 8th- through 12th-grade students. On the basis of
those questionnaires, the researchers created a subset of
7,884 students whose answers identified them as sexually
active. These students' answers formed the basis of the
A respondent's involvement in an incident of either
coerced of forced sex was determined by his or her reply
to the question "Have you ever been forced or
pressured to have sexual intercourse?"
The researchers discovered that "of the sexually
active students, 30.3% of the girls and 9.9% of the boys
reported ever being forced or pressured to have sexual
Risks for certain potentially dangerous behaviors, such
as suicidal tendencies, unprotected sexual activity, or
involvement in an unwanted pregnancy were similar for
those students of either gender who had acknowledged a
previous history of forced intercourse.
However, contrary to their original expectations, the
researchers discovered that "girls who had been in
at least one physical fight in the past year were 1.65
times (65%) more likely than other sexually active girls
to report a history of having forced or pressured
They also found that boys who admitted to having recently
engaged in bulimic activity were more than three times
(3.44) as likely to have been forced or pressured into
unwanted sex than boys whose sexual activity was
exclusively consensual. In contrast, the researchers note
that a history of forced sex seems to play no role in
triggering bulimia among adolescent girls.
Based on their findings, the study authors believe that
any psychiatric therapy focused on children demonstrating
these behaviors should include an investigation of a
possible history of unwanted intercourse.
SOURCE: Archives of Pediatrics
and Adolescent Medicine (1998;152:57-63)
Bite Treatment Often Unnecessary
January 21, 1998
Physicians are ordering unnecessary and
costly blood tests and prescribing ineffective
antibiotics for tick bites, perhaps in response to
patients' insistence on treatment for Lyme disease, a new
The Centers for Disease Control and Prevention and other
medical sources do not recommend blood tests or
antibiotic treatment just after a tick bite, because Lyme
disease is not detectable until several weeks after
infection. Yet, a study in Eastern Maryland, where tick
bites are prevalent, revealed that "(m)ost patients
with tick bites are undergoing costly serologic (blood)
testing of no benefit, and the majority are receiving
prophylactic antibiotic therapy, an intervention of
unproven benefit," according to Dr. Alan D. Fix from
the University of Maryland School of Medicine in
Baltimore and colleagues. The study is reported in
Wednesday's issue of The Journal of the American Medical
Specifically, the researchers report that serologic
testing was performed on two thirds of patients with tick
bites, and that 55% received prophylactic antibiotic
therapy, sometimes before their test results were
returned. Antibiotic therapy was also prescribed for 95%
of patients with Lyme disease and 38% of patients
suspected of having the disease, again many times before
testing was completed.
Physicians treating tick bites "...are either
unaware of recommendations against routine prophylactic
antibiotic therapy, disagree with them, or find them
infeasible in practice," the researchers write.
"Increased educational efforts among physicians
regarding appropriate use of serologic testing seems
warranted, as well as anticipatory counseling of
patients." They also call for more testing to
determine if antibiotic therapy is effective.
In a related editorial, Dr. Alan G. Barbour from the
University of California, Irvine, adds that patients may
be confused by conflicting information they read in the
media and Lyme disease brochures. "We can applaud
the greater participation of patients and their families
in decisions about their medical care," he writes,
"but physicians may be too quick to accede to
patients' demands in some instances." He concludes
that "...for patients to be satisfied with the
no-test, no-medicine option means that additional time
must be taken to explain the rationale behind the
SOURCE: The Journal of the
American Medical Association (1998;279:206-210, 239-240)