A new study published in Stroke, a journal of the American Heart Association, has found that eating citrus fruits such as oranges and grapefruit, may lower your risk of stroke, due to a compound called “flavanone” found in citrus fruits.
The study, which analyzed data on 69,622 women who participated in a large ongoing women’s health study, found that those among the top 20% of participants in terms of the quantity of citrus fruits and juices they reported consuming were 19% less likely to have suffered a stroke during a 14-year follow-up period than those in the bottom 20% of participants in terms of amount of citrus fruit/ juices consumed.
The new study, by researchers in the UK, Italy and at Harvard School of Public Health, was published in the February 23, 2012 issue of Stroke: Journal of the American Heart Association.
The authors state that this was one of the first studies to examine how consuming flavonoid subclasses affects the risk of stroke. Flavonoids are a class of compounds present in fruits, vegetables, dark chocolate and red wine, according to a news release about the study issued by the American Heart Association.
“Flavonoids are thought to provide some of that protection through several mechanisms, including improved blood vessel function and an anti-inflammatory effect,” said Aedín Cassidy, Ph.D., the study’s lead author and professor of nutrition at Norwich Medical School in the University of East Anglia in Norwich, United Kingdom.
The Study; Methodology
Dr. Cassidy and colleagues examined 14-years of follow-up data from the Nurse’s Health Study, a large ongoing women’s health study which included 69,622 women.
The participants in the study reported their food intake, including details on fruit and vegetable consumption every four years.
Over the 14 years of follow-up represented by the data examined, 1,803 incident strokes among study participants were confirmed.
The researchers analyzed the data to determine the extent of relationship, if any, between consumption of six subclasses of flavonoids commonly consumed by Americans (flavanones, anthocyanins, flavan-3-ols, flavonoid polymers, flavonols and flavones) with risk of ischemic, hemorrhagic and total stroke.
The American Heart Association provides information on its website about the different Types of Strokes, in which it refers to ischemic strokes as those characterized by clots and hemorrhagic strokes as those characterized by bleeds.
Findings of the New Study
The researchers did not find an association between total flavonoid consumption and stroke risk. They explained that this was expected, because the biological activity and effects of the different sub-classes of flavonoids differ.
However, the researchers did find that women who reported consuming high amounts of flavanone (mostly in citrus fruits and juices), such that they were in the top fifth of study participants in terms of the extent of citrus fruits in their diets, had a 19 percent lower likelihood of having suffered a blood clot-related (ischemic) stroke during the 14-year follow up period than women in the bottom fifth of participants in terms of the amount of citrus consumed.
In the study, the flavanone consumption reported was primarily from oranges and orange juice (82 percent) and grapefruit and grapefruit juice (14 percent). The study authors, however, recommended eating citrus fruit, rather than juice, because of the high sugar content found in commercial fruit juices.
Conclusions and Implications
“Citrus fruit consumption may be associated with a reduction in stroke risk, and experimental data support these epidemiological associations that the flavanone content of citrus fruits may potentially be cardioprotective,” the researchers concluded.
They pointed out that the findings were consistent with those of some previous studies, but vary from those of other studies.
For example, one previous study found that citrus fruit and juice intake, but not intake of other fruits, protected against risk of ischemic stroke and intracerebral hemorrhage. Another study, however, found no association between consumption of yellow and orange fruits and stroke risk, but did find a correlation between higher consumption of white fruits like apples and pears and lower stroke risk. A third previous study found that Swedish women who ate the highest levels of antioxidants – about 50 percent from fruits and vegetables – had fewer strokes than those with lower antioxidant levels.
The authors conclude that further prospective studies are needed to confirm the associations between consumption of flavonone in citrus fruits and lowered stroke risk found in the new study, and to gain a better understanding about why the association occurs.
One of the researchers, Kathryn M. Rexrode, MD, MPH, of Boston’s Harvard Medical School and Brigham and Women’s Hospital, confirmed this call for further research. While she observed that the new study did find a “modest reduction in stroke risk” associated with consuming flavanone in citrus fruits, nevertheless, she told WebMD (as published by CBS News), “I would certainly not recommend that anyone take flavanone supplements based on this research.”
As reported by CBS News, other medical experts caution that consuming “grapefruit juice and fresh grapefruit can sometimes cause dangerous interactions with medications commonly prescribed to lower heart attack and stroke risk.”
The new research was funded by the National Institutes of Health.
See related HelpingYouCare™ reports on:
- News on Heart Disease & Stroke;
- What are these conditions; Causes;
- Symptoms & Diagnosis;
- Diet & Nutrition: Physical Wellness;
- Exercise: Physical Wellness;
- Sleep, Hygiene, Quit Smoking & Other Healthy Practices: Physical Wellness; and
- Other Areas of Wellness.
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