THURSDAY, Feb. 23 (HealthDay News) -- Eating oranges and other
citrus fruits may help reduce stroke risk, new research
Diets rich in fruits and vegetables have been linked with lower
stroke risk in other studies, but researchers weren't sure why. For
this study, they zeroed in on compounds called flavanones present
in citrus fruits and found a winner.
"These data provide strong support for consuming more citrus fruits as part of your daily fruit and vegetable intake" to reduce the risk of ischemic [blood clot-related] stroke, said study leader Aedin Cassidy, head of nutrition at Norwich Medical School at the University of East Anglia in England.
It's possible that the flavanones in citrus fruits improve blood
vessel function or reduce inflammation, which has been linked with
stroke, the researchers said.
For maximum benefit, whole fruits are preferable to juice
because they contain more flavanones and no added sugar, said
The study, published online Feb. 23 in the journal
Stroke, was funded by the U.S. National Institutes of Health.
Flavanones are a type of dietary flavonoid already associated
with lower stroke risk. Besides fruits and vegetables, flavonoids
are found in red wine and dark chocolate.
For this study, the researchers focused on six subclasses of
flavonoids, including flavanones, to tease out the specific plant
foods that help reduce stroke risk.
The researchers evaluated 14 years of follow-up data from the
U.S. Nurses' Health Study. The new research involved nearly 70,000
women who reported their food intake every four years and included
details on fruit and vegetable consumption.
During the follow-up, 1,803 strokes occurred. About half were
blood clot-related, the study authors noted.
Total flavonoid intake did not reduce stroke risk, but intake of
flavanones did, the researchers said. Women who ate the most
flavanones had a 19 percent lower risk of blood-clot related stroke
than those who ate the least.
The investigators found that 95 percent of the flavanones
consumed came from citrus fruit and juice, mostly orange and
grapefruit. Those consuming the most citrus fruits and juice had a
10 percent reduced risk of stroke compared with those eating none,
Vitamin C, previously suggested as the source of the
cardio-protective effects, was not associated with lower stroke
risk in this study.
Women with the lowest intake of flavanones took in about 150
milligrams a day of flavonoids or less, compared to more than 470
milligrams a day in the highest group.
A typical piece of citrus fruit contains 45 to 50 milligrams of
flavanones, Cassidy said.
The study authors pointed out that those who ate the most
flavonoids also smoked less and exercised more. They ate more
fiber, vegetables and fruit overall and consumed less caffeine and
While the study uncovered an association between flavanone
consumption and reduced stroke risk, it did not prove a
Additional research is needed to better understand the
association between flavanone consumption and stroke risk, the
authors said. While this study only included women, Cassidy
suspects the findings would apply to men. "These studies now need
to be done," Cassidy said.
Hannah Gardener, an epidemiologist at the University of Miami
Miller School of Medicine department of neurology, said the study
adds valuable information to what is known about diet and stroke
"There are several studies that have shown that greater consumption of fruits and vegetables has been linked with reduced risk of stroke," said Gardener, who was not involved in the study. What the new research adds is the focus on the subclasses of flavonoids, she said.
The bottom line? "It underscores the importance of fruit and
vegetable intake," Gardener said. And it "provides evidence that
citrus fruits in particular may be important in terms of reducing
The U.S. Dietary Guidelines of America 2010 suggest filling half
your plate with fruits and vegetables.
Cassidy and a co-author report receiving funding from Unilever
Research and GlaxoSmithKline to conduct trials and studies on
flavonoid-rich foods in the past.
To learn more about
dietary recommendations, go to the U.S. Department of
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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