A naturally-occurring compound in citrus fruits
may reduce stroke risk, according to research
reported in Stroke: Journal of the American Heart Association. Eating higher amounts of oranges
and grapefruit, may lower ischemic stroke risk.
Women who ate high amounts of the compound
had a 19 percent lower risk of ischemic stroke
than women who consumed the least amount.
Researchers examined how consuming flavonoids affects the risk of stroke. Flavonoids are the specific
class of protective nutritive compounds present in fruits, vegetables, dark chocolate and red wine.
"Studies have shown higher fruit, vegetable and specifically vitamin C intake is associated with
reduced stroke risk," said the study's nutrition researchers from Norwich Medical School in the
University of East Anglia in Norwich, United Kingdom. "
Flavonoids are thought to provide some of that protection through several mechanisms, including improved blood vessel function and an overall anti-inflammatory effect."
The team used 14-years of follow-up data from the Nurse's Health Study, which included 69,622
women who reported their food intake, including details on fruit and vegetable consumption every
four years. Researchers examined the relationship of the 6 major subclasses of flavonoids commonly consumed in the U.S. diet (including: flavanones, anthocyanins, flavan-3-ols, flavonoid polymers, flavonols and flavones) with risk of ischemic, hemorrhagic and total stroke.
As expected, the researchers didn't find a beneficial association between total flavonoid consumption and stroke risk, as the biological activity of each differ. However, they found that women who ate high amounts of flavanones in citrus had a 19 percent lower risk of blood clot-related (ischemic) stroke than women who consumed the least amounts.
In the study, flavanones came primarily from oranges and orange juice (82 percent) and
grapefruit and grapefruit juice (14 percent).
It is important to note, the researchers strongly
recommended that people increase their citrus
fruit intake, preferred to juice, because of the high
sugar content of commercially-available fruit juices.
A previous study also found that citrus fruit and juice intake, but not intake of other fruits, protected against risk of ischemic stroke and intra-cerebral hemorrhage. There was also a study that found no association between yellow and orange fruits and stroke risk, but did link increased consumption of white fruits like apples and pears with lower stroke risk. Another study found that women from Sweden who ate the highest levels of antioxidants approx 50 percent from fruits and vegetables, had fewer strokes than those with lower antioxidant levels.
More studies are needed to confirm the association between flavanone consumption and stroke risk, and to gain a better understanding about why the association occurs, the researchers added.
The National Institutes of Health funded the research.
Story Source: American Heart Association
(2012, February). Eating citrus fruit may lower
women's stroke risk
Journal Reference: Dietary Flavonoids and Risk of Stroke in Women. Stroke, February 23 2012
This article is for informational and educational purposes only; It is not intended to provide medical advice, diagnosis or treatment. Consult your doctor orhealthcare professional.
