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.