Coffee May Reduce Strokes in Women

Reduced Stroke Risk In Women
Linked To Daily Coffee Drinking

Drinking more than
one cup of coffee a day
was associated with a
22 percent to 25 percent
lower risk of stroke,
compared with those
who drank less, in a
study reported in "Stroke"

Journal of the American Heart Association.

Low or no coffee consumption was associated with
an increased risk of stroke in a study of 34,670 women
(ages 49 to 83) followed for an average 10.4 years.
Although it may be too soon to change coffee-drinking

habits, the study should ease the concerns of some
women, the researchers suggested.

Coffee is one of the most widely consumed beverages
in the world. "Therefore, even small health effects of

substances in coffee may have large public health

consequences," said researchers conducting the study
from the Division of Nutritional Epidemiology, National

Institute of Environmental Medicine, Karolinska

Institute in Stockholm, Sweden.

Groups of people who reported drinking 1-2 cups per
day, 3-4 cups per day or 5 or more cups per day had
similar benefits compared with those who reported daily

intake of less than a cup of coffee, researchers said.

The differences were unchanged by smoking status,
body mass index, history of diabetes, hypertension
or alcohol consumption, indicating that coffee's effects
are not influenced by those known cardiovascular risk

factors.

Scientists have theorized that coffee could have either
beneficial or harmful effects on the cardiovascular
system, but earlier studies have been inconclusive.
Only one previous prospective study, which was also

inconclusive, examined the association between coffee

consumption and stroke incidence in healthy women.

"Our research group has previously observed an
inverse association between coffee consumption and
risk in Finnish male smokers," the researchers said.
"We wanted to assess the situation in women."

The women participated in the long-running Swedish
Mammography Cohort, an epidemiological study

investigating the association between diet, lifestyle
and disease development. All the women were free
of cardiovascular disease and cancer at baseline in
1997, when they answered the food frequency
questionnaire analyzed in the study.

Researchers collected data on cases of first stroke
that occurred between Jan. 1, 1998 and Dec. 31, 2008,
by linking the study group with the Swedish Hospital

Discharge Registry that provides almost complete
coverage of Swedish hospital discharges.

Researchers documented 1,680 strokes: 1,310
cerebral infarctions/ischemic strokes (caused by
blockages), 154 intracerebral hemorrhages (caused
by bleeding inside the brain), 79 subarachnoid
hemorrhages (caused by bleeding on the surface
of the brain) and 137 unspecified strokes.

After adjustment for other risk factors, coffee
consumption was associated with a statistically
significant lower risk of total stroke, cerebral infarction
and subarachnoid hemorrhage.

The small numbers of intracerebral hemorrhage could
have factored in the lack of an association with that
stroke subtype, she said. In general, cerebral infarction

is most strongly associated with dietary factors.

The food frequency questionnaire made no distinction
between regular and decaffeinated coffee but
decaffeinated coffee consumption in the Swedish

population is low.

Potential ways that coffee drinking might reduce
the risk of stroke include weakening subclinical
inflammation, reducing oxidative stress and improving
insulin sensitivity, they said.

The study's limitations include the use of a self-
administered questionnaire to determine medical

history and history of coffee consumption, which
inevitably includes some measurement error and

mis-classification of exposure, and the possibility
of an unrecognized confounding factor associated
with either low or moderate coffee consumption.

"Some women have avoided consuming coffee
because they have thought it is unhealthy. In fact,
increasing evidence indicates that moderate coffee

consumption may decrease the risk of some diseases
such as diabetes, liver cancer and possibly stroke."

More studies on coffee consumption and stroke are
needed before firm conclusions can be reached,
they said.

Story Source: American Heart Association

Journal Reference: Coffee Consumption and
Risk of Stroke in Women. Stroke, 2011;