By Suzanne Rostler
NEW YORK, May 26 (Reuters Health) - An apple a day may keep stroke at bay,
new study findings suggest.
According to a report in the May issue of the European Journal of Clinical
Nutrition, men and women who ate the equivalent of one apple per day had a lower
risk of stroke than individuals who did not eat apples.
While it is not clear why apples appear to lower stroke risk, the authors
suggest that lifestyle factors such as good diet and exercise habits, which may
be associated with eating apples, or other beneficial compounds in the fruit,
may play a role.
"One speculative possibility is that the effect comes from some phenolic
acids present in apples," lead author Paul Knekt from the National Public Health
Institute in Helsinki, Finland, said in an interview with Reuters Health.
Phenolic acids are a class of antioxidants, or compounds that quench free
radicals. These unstable molecules are byproducts of normal metabolism that clog
arteries and cause changes to DNA that can lead to cancer and other diseases.
Whatever the reason, lower risk of stroke does not appear to be the result
of quercetin, an antioxidant found in apples. Previous studies have reported a
link between intake of flavonoids, a group of antioxidants that includes
quercetin, and decreased risk for several chronic diseases.
According to results, men who developed a stroke over the 28-year follow-up
period consumed 3.57 mg of quercetin a day compared with just 3.68 mg a day for
men who did not have a stroke. Women who went on to have a stroke consumed 4.09
mg of quercetin a day compared with 4.07 mg a day for other women.
Though "the results suggest that the intake of apples is related to a
decreased risk of thrombotic stroke," the study authors write, "this association
apparently is not due to the presence of...quercetin.... The suggestive
protective effect of apple intake may thus be due to some other substances in
the fruit or simply to lifestyle associated with apple intake," they add.
Thrombotic strokes are caused by blood clots that interfere with the free
circulation of blood. Another type of stroke is hemorrhagic; that is, it
involves the 'bursting' of a vessel, and a resultant hemorrhage. Both types of
stroke ultimately cause damage because tissues are not adequately supplied by
oxygen-rich blood.
The researchers analyzed food intakes of more than 9,000 healthy men and
women at least 15 years of age.
Men who ate more than 54 grams of apple a day and women who ate more than 71
grams of apple a day--the equivalent of about one apple--had a lower risk of
stroke than those with the lowest apple intake.
Based on the findings, Knekt recommends that people continue to eat a diet
rich in fruits and vegetables, "since it is apparent that this will protect us
from cardiovascular diseases and some cancers," he told Reuters Health.
"The question whether there is an extra beneficial effect of apple
consumption I would like to leave open until some other studies, carried out in
different circumstances, have reported a similar finding as our study," he
added.
In other findings, diabetics with high intakes of quercetin appeared to be
at increased risk of stroke. The authors said they have no explanation for the
"unexpected finding."
