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P age A4
O ctober 4, 1995 • T he P ortland O bserver
Science
W e ig h in g C a ffe in e ’s H e a lth e f f e c t s
W3r
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With coffee bars proliferating
from Seattle to Boston, and the spe­
cialty coffees they feature promising
to turn around a decades-long de­
cline in American coffee consump­
tion, the news about coffee’s effects
on health is surprisingly good.
A substantial amount o f research,
including several large studies done
in the last few years, has turned up
very little solid scientific evidence to
indict a moderate intake of coffee or
caffeine as a serious or even minor
health threat.
“Some of the most serious haz­
ards that were linked to caffeine in
the past have not panned out,” said
Dr. James L Mills, who studies caf­
feine’s effects on pregnancy at the
National Institute of Child Health
and Human D evelopm ent in
Bethesda, Md.
After peaking in 1962 at 3.12
cups per person a day, coffee con­
sumption endured a 30-year slide in
popularity, finally stabilizing in the
mid-1990s around 1.7 cups, accord­
ing to a survey conducted last winter
by the National Coffee Association.
O f course, caffeine is also present
in black and green teas and in soft
drinks. Eighty percent of Americans
consume at leas, one beverage con-
tainingcalfeine every day, and among
Americans over 18, the per capita
consumption of caffeine is about 200
milligrams a day.
Mills noted that heavy caffeine
consumers - those who drink eight or
more five-ounce cups ofcoffee a day
- tend to be “very overworked, driv­
en people who are generally no, the
best health risks.”
For the average healthy person,
about the most serious charge sci­
ence can levy against caffeine is that
it may be addictive. After 18 to 24
hours, its absence, even in those who
consume it moderately, sometimes
results in withdrawal symptoms, in­
cluding severe headaches, fatigue,
depression and poor concentration.
Concerns about the effects of
caffeine on pregnancy and fetal de­
velopment also persist.
Despite a score of studies on the
relationship between caffeine and a
woman’s ability to conceive and de­
liver a full-term, full-size, healthy
infant, researchers are still arguing
about the reproductive risks of rela­
tively high doses o f caffeine before
or during pregnancy. All relevant
studies have suffered from one or
more methodological limitations that
might invalidate their findings, sci­
entists say.
And while moderate consump­
tion - usually defined as two to four
five-ounce cups of coffee daily - has
thus far received a relatively clean
bill of health even in people at high
risk for developing heart disease or
cancer, new studies have linked heavi­
er daily intakes to heart attacks and
bone loss in women.
And in men with mild high blood
pressure, several recent studies have
shown that a significant rise in blood
pressure can occur after jus, twe or
three cups of coffee, especially if caf­
feine is consumed before exercising.
Along with these cautionary
findings has come encouraging news
about caffeine’s potential role in
weight control.
Caffeine raises the rate at which
the body bums calories for three or
more hours after it is consumed, ac­
cording to studies of healthy volun-
teers of normal weigh, in Denmark.
Just 100 milligrams of caffeine - the
amount in one cup of coffee or two
cans of cola - can raise the metabolic
rate by 3 to 4 percent, and larger
intakes raise it even higher If the
consumer also exercises, the caloric
burn stimulated by caffeine is greater
still. But caffeine is no free lunch for
dieters because it also effects the
release of insulin, causing blood sug-
artc fall, which induces hunger pangs.
Caffeine’sabilitytobolsterphys-
ical performance is well known
among professional athletes.
A recent study by Dr . Terry Gra­
ham and Dr. Lawrence L. Spriet a,
the University of Guelph in Ontario
indicated that even a moderate
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amount of caffeine - 1.5 milligrams
per pound of body weight - had a
potent exercise-enhancing effect.
Caffeine helps to mobilize body fat
and make i, available as fuel for
exercising muscles, allowing them to
work longer before they fatigue
Caffeine, known chemically as
1,3,7-trimethylxanthine, is one of a
class of methylxanthine compounds
found in 63 plant products, including
tea leaves, cocoa beans and coffee
beans.
Similar to amphetamines bu,
milder in its effects, caffeine stimu­
lates the sympathetic nervous sys­
tem, which regulates the body’s au­
tomatic functions.
Asa central nervous system stim­
ulant, it makes people feel more alert,
temporarily relieves fatigue and pro­
motes quick thinking Its contrary
effects on blood vessels often render
it medically useful: it dilates arteries
feeding the heart, increasing blood
flow, and constricts arteries in the
head, helping to counter migraine
headaches.
But caffeine is only one, albeit
the best known, o f some 500 chemi­
cals in coffee.
Indeed, caffeine was recently ab­
solved of at least one of coffee’s
reputed ill effects - the ability to raise
serum cholesterol levels. That draw­
back, researchers in the Netherlands
say, stems not from caffeine bu, from
the oils in coffee beans that are ex­
tracted when the grounds are boiled.
Those oils are not a problem when
coffee is brewed through a paper
filter, because the oils are left be­
hind.
Decaffeinated coffee has late­
ly captured a growing body of dev­
otees who spurn caffeine’s stim u­
lating effect bu, still covet cof­
fee’s flavor and social attributes.
Yet, research sponsored by the
National Institutes o f Health and
directed by Dr. H Robert Superko
while at Stanford University has
suggested that decaffeinated cof­
fee is more likely than its caf­
feine-rich counterpart to raise lev­
els o f artery-damaging LDL cho­
lesterol.
He said this condition may oc­
cur because stronger-flavored coffee
beans, known as robusta, are typical­
ly used to prepare decaffeinated cof­
fee to compensate for the flavor lost
in the decaffeinating process. These
same beans are used to prepare in­
stant coffees with and without caf­
feine But most brewed coffee con­
taining caffeine is prepared from
milder arabica beans. This finding
has not ye, been confirmed by other
studies.
Sorting out the health effects of
drinking coffee, with or without caf­
feine, is complicated by the fact that
coffee drinkers are, on the whole, a
different breed from drinkers o f oth­
er beverages, includingcaffeine-con-
taining tea. A, least three large stud­
ies conducted here and in Europe
have shown that coffee drinking, es­
pecially at high levels, is associated
with behavior that is I inked to serious
illnesses, like cigarette smoking.
Furthermore, decaf drinkers are
different from those who drink cof­
fee with caffeine.
In a study of 2,677 adults by
Alan Levitonand Elizabeth N. Allred
o f Harvard Medical School and Bos­
ton Children’s Hospital, which was
published last year, women who
drank only decaffeinated coffee be­
haved more like women who drank
no coffee at all than like women who
consumed coffee with caffeine.
Decaf drinkers in the study were
more I ikely than other women to take
vitamin supplements, eat vegetables
in the cabbage family, use seat belts
routinely and exercise regularly. The
men who drank decaf exclusively
typically weighed less and were more
likely to consume a low-fat diet and
to eat such vegetables.
To determine whether drinking
coffee increases the risk of disease,
researchers must take into account
many “life style” factors, since these
factors and not coffee or caffeine
could be responsible.
Breaking Bad
Medical News
A majority of elderly people of
Korean and Mexican descent would
prefer no, to be told they suffer from
a terminal illness, while African-
Americans and European Americans
side with knowing the bad news,
researchers reported last week.
The ethnic differences over
whether physicians should disclose a
poor prognosis to a patient was re­
flective of cultural, and not econom­
ic differences, researchers at the
University of Southern California in
Los Angeles said.
“This finding suggests that phy­
sicians should ask their patients if
they wish to receive information and
make decisions or if they prefer that
their families handle such matters,”
study author Leslie Blackhall wrote.
The study of 800 nursing home
residents found that only 35 percent
of Korean Americans and 48 percent
of Mexican Americans would want
to be told o f a terminal piognosis.
In contrast, 63 percent of blacks
and 69 percent of whites responded
that they would want to be told the
bad news.
Koreans and Mexicans were also
less inclined to make their own deci­
sions about whether to receive life
support, preferring the choice be
made by their families, the article in
the Journal of,he American Medical
Association said.
In the same journal, a separate
article about the customs of Navajo
Indians found that members of the
tribe — who have a powerful con­
cept of well-being called “hozho” —
want their caregivers to think and
speak only positively.
Such cultural differences should
be considered by ethical review
boards, which are usually made up of
doctors and hospital administrators,
Lawrence Gostin ofthe Georgetown/
Johns Hopkins Program on Law and
Public Health wrote in an accompa­
nying article.
srrn rr
We’ re your Neighbors fo r
Medi care Coverage
W hat?
Legacy Health System cordially invites you to be our
guests at a fun and informative Open House at Legacy
Emanuel Hospital & Health Center.
Why?
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“A New Prescription for Women’s
Health: Getting the Best Medical
Care in a Man’s World”
[W<11
by Bernadine Healy, M.D.
former director,
National Institutes of Health, and
a leading force in the creation
of the Women's Health Initiative
You 're going to
have a field day!
Tuesday, O ctober 10, 1995
2:00 p.m.
Berg Swann Auditorium
Portland Art Museum
Call (503) 335-2466
to reserve seats
Sponsored by
KAISER P E R M A N E M T t
LEGACY
Center for Health Research
Health System
Classified and Bid Advertisement
Deadline is Monday, 12:00 Keen.
t
Because we want to personally introduce you to your
community hospital. You’ll receive an insightful close-up
tour of Legacy Emanuel Hospital. You’ll also leam about
First Choice Sixty-Five, a federally qualified Medicare
health maintenance organization (HMO) offered by HMO
Oregon, a subsidiary of Blue Cross and Blue Shield of
Oregon. First Choice Sixty-Five is your key in the door to
the excellent services provided by Legacy Emanuel
Hospital and throughout Legacy Health System.
Refreshments will be served and we’ll answer any
hospital or insurance-related questions you may have.
We’re proud of our hospital and our commitment to the
community. We want to show and tell you what we’re all
about.
When?
Our 50+ Adult Field Day at Legacy Emanuel Hospital
happens on October 11 and November 8 beginning at 10
a.m. Transportation is available. Call 335-3500 to find
out more and to pre-register.
Legacy Health System includes Emanuel Hospital & Health Center. Good Samaritan Hospital & Medical Center. Meridian Park Hospital Mount Hood Medical rente, v.c,u„., «
and lareMark/Managed Healthcare Xonhwest PPO C I9 9 5 . Blue Cross and Blue Shield of Oregon and HMO Oregon are mdependent I k e n S Z B l Ä a n Ä s h S w
.
. .