Celery Flavonoid May Reduce Brain Inflammation
Filed Under News May 22, 2008
Luteolin an antioxidant, found in celery, has been found to reduce brain inflammation linked to Alzheimer’s disease in a study of mice that suggests some plant chemical’s may help protect the brain.
Mice given Luteolin, which also found in hot peppers, parsley and chamomile tea, had less inflammation than other rodents when researchers tested them with a bacteria, according to a study in the May 27 issue of the Proceedings of the National Academy of Sciences.
Brain inflammation has been linked in other studies to Alzheimer’s disease, multiple sclerosis and memory loss. This study, the first to focus on luteolin’s brain-protecting properties, showed the substance modulates the body’s response to diseases that inflame the brain. Luteolin and other plant chemicals, called flavonoids, also reduce cardiovascular disease and stroke in humans.
“We’re not recommending anyone go out and binge on celery, but the ability to mitigate brain inflammation through the diet is exciting,'’ said Rodney W. Johnson, the study’s author and an associate professor in the department of animal sciences at University of Illinois at Urbana-Champaign.
Cocoa may help lower blood pressure
Filed Under News May 13, 2008
Foods rich in cocoa appear to reduce blood pressure but drinking tea may not, according to a team of German researchers. The findings, published in the Journal of the American Medical Association (JAMA), do not indicate a widespread recommendation for higher cocoa intake to decrease blood pressure, but the researchers say it appears reasonable to substitute phenol-rich cocoa products such as dark chocolate for other high-calorie or high-fat desserts or dairy products.
“We believe that any dietary advice must account for the high sugar, fat and calorie intake with most cocoa products,” the authors conclude.
“Rationally applied, cocoa products might be considered part of dietary approaches to lower hypertension risk.”
Current guidelines advise individuals with hypertension (high blood pressure) to eat more fruits and vegetables, the authors note.
Compounds known as polyphenols or flavonoids in fruits and vegetables are thought to contribute to their beneficial effects on blood pressure and cardiovascular risk.
“Tea and cocoa products account for the major proportion of total polyphenol intake in Western countries,” the authors write. “However, cocoa and tea are currently not implemented in cardioprotective or anti-hypertensive dietary advice, although both have been associated with lower incidences of cardiovascular events.”
Dr Dirk Taubert and colleagues at the University Hospital of Cologne, Germany, conducted a meta-analysis of 10 trials, five of cocoa’s effects on blood pressure and five involving tea.
The studies were either randomized trials, in which some participants were randomly assigned to cocoa or tea groups and some to control groups, or used a crossover design, in which participants’ blood pressure was assessed before and after consuming cocoa products or tea.
The five cocoa studies involved 173 participants, including 87 assigned to consume cocoa and 86 controls, 34 per cent of whom had hypertension (high blood pressure).
Four of the five trials reported a reduction in both systolic (the top number, when the heart contracts) and diastolic (the bottom number, when the heart relaxes) blood pressure.
Compared with those who were not consuming cocoa, systolic blood pressure was an average of 4.7 millimetres of mercury lower and diastolic blood pressure was an average of 2.8 millimetres of mercury lower.
The effects are comparable to those achieved with blood pressure- lowering medications, the authors note.
“At the population level, a reduction of 4 to 5 millimetres of mercury in systolic blood pressure and 2 to 3 millimetres of mercury in diastolic blood pressure would be expected to substantially reduce the risk of stroke (by about 20 per cent), coronary heart disease (by 10 per cent) and all-cause mortality (by 8 per cent),” they write.
Of the 343 individuals in the five tea studies, 171 drank tea and 172 served as controls, for a median duration of four weeks. Drinking tea was not associated with a reduction in blood pressure in any of the trials.
Tea and cocoa are both rich in polyphenols, but while black and green tea contain more compounds known as flavan-3-ols, cocoa contains more of another type of polyphenol, procyanids.
“This suggests that the different plant phenols must be differentiated with respect to their blood pressure-lowering potential and thus cardiovascular disease prevention, supposing that the tea phenols are less active than cocoa phenols,” the authors write.
Flavonoids in plants found to have beneficial effect on Alzheimer’s
Filed Under News May 8, 2008
A set of molecules found in certain plants appears to have a beneficial effect in brain tissue associated with Alzheimer’s disease, according to a new study conducted in mice. The study was led by researchers at the University of South Florida and Cedars-Sinai Medical Center.
Researchers administered molecules called flavonoids, which are found in certain fruits and vegetables, to a mouse model genetically programmed to develop Alzheimer’s disease. Using two of these molecules, luteolin and diosmin, they were able to reduce the levels of a protein called amyloid-beta, which forms the sticky deposits that build up in the brains of patients with Alzheimer’s. The researchers also determined that these molecules work by targeting a protein called presenilin-1, which has long been linked to Alzheimer’s as a genetic cause of this devastating and untreatable illness.
The results may offer a new approach to therapy for patients suffering from this neurodegenerative illness, which is the most common cause of dementia and is estimated to affect more than five million people in the United States.
These flavonoids are widely available in natural foods and it appears that they may be used in purified form as therapeutic agents. The compounds have few if any side effects and are naturally occurring in citrus fruits.
Grapefruit Favonoid Naringenin Inhibits Hepatitis According to Study
Filed Under News May 7, 2008
The grapefruit flavonoid naringenin inhibits the secretion of Hepatitis C virus (HCV) in infected cells and could offer a new approach for treating the disease, according to a Harvard Medical School study.
About 3 percent of the global population is infected with HCV, which can lead to cirrhosis and liver cancer. The current standard therapy of interferon and ribavirin is only effective in about 50 percent of cases and can cause major side effects, according to background information in the study.
Recent research suggests that HVC may be “hitching a ride” along the lipoprotein life cycle, and that compounds and dietary supplements that influence lipoprotein metabolism may also affect HCV.
In this new study, researchers demonstrated that HCV is actively secreted by infected cells while bound to a very low-density lipoprotein.
“Silencing apolipoprotein B in infected cells causes a 70 percent reduction in the secretion of both ApoB-100 and HCV. This ApoB-dependent HCV secretion pathway suggests a novel therapeutic approach for the treatment of HCV infection,” the researchers wrote.
They then tested the grapefruit flavonoid naringenin and found it reduced HCV secretion in infected cells by 80 percent.
“The concept of supplementing HCV patients’ diets with naringenin is appealing,” the researchers wrote. But they noted the intestinal wall doesn’t absorb naringenin well, which means therapeutic doses of the flavonoid would have to be given by injection or combined with other compounds to boost its absorption by the intestines.
The researchers also noted that naringenin and several other compounds in grapefruit have significant drug-drug interactions.
“Future studies would focus on long-term ability of naringenin and perhaps other citrus flavonoids to reduce viral load in animal models and long-term cultures of primary human hepatocytes,” the researchers concluded.
The study was published in the May issue of Hepatology.
Diabetes - Alzheimer’s and Antioxidants
Filed Under News May 2, 2008
In a new study, researchers at the Salk Institute and UCSD, said some of the factors that cause diabetes might also trigger Alzheimer’s. In particular, their report found that the inability to process insulin caused swelling of the brain, damaged blood vessels there and hastened the death of neural cells in certain diabetic mice.
They believe a similar process might be taking place in humans.
The work provides yet another motivation for combating obesity and the growing diabetes epidemic it is fueling in the United States. It also suggests that onset of Alzheimer’s could be delayed or even prevented in some people if they don’t become diabetic earlier in life, said David Schubert, the lead investigator and professor at the institute’s Cellular Neurobiology Laboratory.
“The important point to make is not to get obese and develop diabetes,” Schubert said. “It’s a warning signal. It emphasizes that you don’t want to get diabetes when you’re young.”
The analysis led by Schubert is published in the current online edition of the medical journal Neurobiology of Aging. The study was co-authored by fellow Salk researchers Joseph Burdo and Qi Chen and diabetes expert Nigel Calcutt, who teaches in the pathology department at the University of California San Diego. The researchers are based in La Jolla.
Besides offering an explanation for the combination of diabetes and Alzheimer’s in some individuals, the report suggests that people at risk of developing Alzheimer’s could benefit from consuming foods and supplements rich in antioxidants, including fish, beans, berries, vegetables, fish oil and vitamin E, said researchers such as Greg Cole, associate director of the UCLA Alzheimer’s Center.
Antioxidants can help fight advanced glycation, the buildup of certain toxic protein molecules that can harm some blood vessels and lead to destructive inflammation of the brain.
