Citrus wards off risk of stroke
Eating
foods that contain vitamin C may reduce your risk of the most common type of
hemorrhagic stroke, according to a study presented at the American Academy of
Neurology's 66th Annual Meeting in Philadelphia, April 26 to May 3, 2014.
Vitamin
C is found in fruits and vegetables such as oranges, papaya, peppers, broccoli
and strawberries. Hemorrhagic stroke is less common than ischemic stroke, but
is more often deadly.
The
study involved 65 people who had experienced an intracerebral hemorrhagic
stroke, or a blood vessel rupture inside the brain. They were compared to 65
healthy people. Participants were tested for the levels of vitamin C in their
blood. Forty-one percent of cases had normal levels of vitamin C, 45 percent
showed depleted levels of vitamin C and 14 percent were considered deficient of
the vitamin.
On
average, the people who had a stroke had depleted levels of vitamin C, while
those who had not had a stroke had normal levels of the vitamin.
"Our
results show that vitamin C deficiency should be considered a risk factor for
this severe type of stroke, as were high blood pressure, drinking alcohol and
being overweight in our study," said study author Stéphane Vannier, MD,
with Pontchaillou University Hospital in Rennes, France. "More research is
needed to explore specifically how vitamin C may help to reduce stroke risk.
For example, the vitamin may regulate blood pressure."
Vannier
adds that vitamin C appears to have other benefits like creating collagen, a
protein found in bones, skin and tissues.
Vitamin
C deficiency has also been linked to heart disease.
Citrus Fruits May Help Women Reduce Risk Of Stroke
Eating
citrus fruits, especially oranges and grapefruit, because of the flavonone they
contain, may lower women's risk of developing clot-associated or ischemic
stroke, according to a new study led by Norwich Medical School of the
University of East Anglia in the UK that was published online in Stroke: Journal of the American Heart
Association. (February, 2012).
The
researchers wanted to examine more closely how consumption of foods containing
different classes of flavonoids affected the risk of stroke.
Flavonoids
are a group of compounds found in fruits, vegetables, dark chocolate and red
wine.
Study
lead author and professor of nutrition at Norwich Medical School, Dr Aedín
Cassidy, told the press:
"Studies
have shown higher fruit, vegetable and specifically vitamin C intake is
associated with reduced stroke risk."
A
stroke is where part of the brain shuts down because of loss of blood supply,
caused either by a blockage or embolism that stops the blood flow (ischemia),
or due to leakage caused by a hemorrhage.
Cassidy
said flavonoids are thought to provide some protection against stroke by
improving blood vessel function and reducing inflammation, among other things.
For
their study, Cassidy and colleagues examined data from the Nurse's Health
Study. Based in the US, this is one of the largest and longest running
investigations of factors that influence women's health. It started in 1976 and
expanded in 1989.
The
researchers looked at 14 years of follow-up data completed by 69,622 female
participants who every four years had reported their dietary intake, including
details of the fruits and vegetables they consumed.
They
looked for links between the six major subclasses of flavonoids commonly
present in the American diet and risk of ischemic, hemorrhagic and total
stroke.
The
six major subclasses they examined were: flavonones, anthocyanins,
flavon-3-ols, flavonoid polymers, flavonols and flavones.
Since
we already know that each subclass has a different biological effect, the
researchers did not expect to find any strong beneficial links between total
flavonoid consumption and stroke risk.
But
they did find a strong link between high consumption of flavonones in citrus
fruits and reduced stroke risk: women who consumed the most showed a 19% lower
risk of ischemic stroke compared to women who ate the least amounts of
flavonones in citrus fruits.
In
this study, oranges and orange juice (82%) and grapefruit and grapefruit juice
(14%) had the highest amounts of flavonones. But the researchers said if you
are looking to increase your intake, then go for the fruit rather than the
juice, because the latter tends to be accompanied by high amounts of sugar.
While
previous studies have shown links between various foods and protection against
both kinds of stroke, and this study further informs the field, the researchers
said we still need to get a better understanding about why the link occurs, and
that has to come from further research.
Grapefruit and oranges have been shown to lower cholesterol levels
Compounds
in grapefruit and oranges have been shown to lower cholesterol levels in the
blood. Two flavanones, hesperidin and naringin, were extracted from citrus
fruits and fed to rats split into groups with some receiving high levels of
cholesterol in their diet. Shela Gorinstein of The Hebrew University in
Jerusalem found that after 30 days cholesterol levels in rats' blood reduced by
around 20-25% in those fed a cholesterol-rich diet (Journal of the Science of
Food and Agriculture DOI: 10.1002/jsfa.2834). David Bender, Sub-dean at the
Royal Free and University College Medical School, London, believes that the
results show a significant reduction in the increase in plasma lipids caused by
cholesterol feeding. "This is potentially beneficial to health with
regards to heart disease", he added.
Tangerines Fight Obesity/Protect Against Heart Disease
New
research from The University of Western Ontario has discovered a substance in
tangerines not only helps to prevent obesity, but also offers protection
against type 2 diabetes, and even atherosclerosis, the underlying disease
responsible for most heart attacks and strokes.
Murray
Huff, a vascular biology scientist at the Schulich School of Medicine &
Dentistry, along with Erin Mulvihill, a PhD student, studied the effects of a
flavonoid in tangerines called Nobiletin. Their research is published May, 2011
in the journal Diabetes.
In
a model of metabolic syndrome developed by the Huff laboratory at the Robarts
Research Institute, mice were fed a "western" diet high in fats and
simple sugars. One group became obese and showed all the signs associated with
metabolic syndrome: elevated cholesterol and triglycerides, high blood levels
of insulin and glucose, and a fatty liver. These metabolic abnormalities
greatly increase the risk of cardiovascular disease and type 2 diabetes.
The
second group of mice, fed the exact same diet but with Nobiletin added,
experienced no elevation in their levels of cholesterol, triglycerides, insulin
or glucose, and gained weight normally. Mice became much more sensitive to the effects
of insulin. Nobiletin was shown to prevent the buildup of fat in the liver by
stimulating the expression of genes involved in burning excess fat, and
inhibiting the genes responsible for manufacturing fat.
"The
Nobiletin-treated mice were basically protected from obesity," says Huff,
the Director of the Vascular Biology Research Group at Robarts. "And in
longer-term studies, Nobiletin also protected these animals from
atherosclerosis, the buildup of plaque in arteries, which can lead to a heart
attack or stroke. This study really paves the way for future studies to see if
this is a suitable treatment for metabolic syndrome and related conditions in
people."
Huff's
research has focused on the pharmacological properties of naturally-occurring
bioactive molecules. Two years ago, his research drew international attention
when he discovered a flavonoid in grapefruit called Naringenin offered similar
protection against obesity and other signs of metabolic syndrome. Huff says
"What's really interesting to us is that Nobiletin is ten times more
potent in its protective effects compared to Naringenin, and this time, we've
also shown that Nobiletin has the ability to protect against
atherosclerosis."
"Having
that vitamin C seems to do it," Ferruzzi said. "And if you don't want
to squeeze a lemon into your cup, just have a glass of juice with your green
tea."
Connie
Weaver, head of the National Institutes of Health Purdue University-University
of Alabama at Birmingham Botanical Research Center for Age-Related Diseases,
which funded the research, said the study's focus was an important part of
understanding how to get the most out of compounds considered beneficial.
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