Fatty acid catabolism higher due to polyphenol intakeMay 15, 2007Polyphenols, dietary substances from vegetables, fruits and green tea, bring about a change in the energy metabolism. Dutch researcher Vincent de Boer has discovered that polyphenols increase the fatty acid breakdown in rats and influence the glucose use in fat cells. De Boer carried out his doctoral research at RIKILT - Institute of Food Safety in Wageningen. Much research into the health effects of polyphenols is carried out in vitro. However in the body, polyphenols are quickly and easily converted into polyphenol metabolites. This research was carried out with rats to study the mechanisms and effects of a polyphenol-rich diet. Relevant polyphenol metabolites that are found in humans were also examined. Quercetin is a polyphenol that is highly abundant in the human diet, such as onions, apples and tea. The study revealed that quercetin metabolites mainly end up in the lungs of rats. Subsequently De Boer discovered that lung cells had a greater fatty acid catabolism if the animals constantly received quercetin in their feed.
Energy regulation The energy-sensing protein SIRT1 is an important regulatory protein that can prolong the life span of model organisms such as yeast and fruit flies. In humans, SIRT1 is possibly involved in the regulation of energy use. The SIRT1 activity can be simulated by various polyphenols. De Boer discovered that polyphenols from green tea stimulated the activity of isolated SIRT1. The quercetin molecule also did this, but an important human quercetin metabolite had the opposite effect. Therefore in intestinal cells, quercetin had no effect on the activity of SIRT1. In experiments with fat cells, both quercetin and a quercetin metabolite were found to change the glucose use in the fat cell. A change in the energy regulation might be an important process for the realisation of possible health effects of polyphenols in the food. This provides new starting points for further research into the molecular mechanisms of polyphenols. This will allow the health effects of polyphenols to be accurately described. Polyphenols Polyphenols are substances of plant origin that occur in numerous fruits and vegetables. Due to their possible health effect, polyphenols are currently sold as nutritional supplements. Yet the scientific basis for the health claims for polyphenols is mostly weak. Results from in vitro studies are often directly translated into possible beneficial health effects in humans. De Boer's research shows that in vivo research with polyphenol metabolites is necessary to study the effects of polyphenols. Rubicon Vincent de Boer recently received a Rubicon fellowship from NWO for his new research into the role of mitochondrial SIRT1 analogues in aging and energy metabolism. He will carry out his research at the Department of Pathology at the Harvard Medical School in Boston. Netherlands Organisation for Scientific Research | |||||||||||||||||||||
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Related Polyphenol News Articles Study indicates grape seed extract may reduce cognitive decline associated with Alzheimer's disease A compound found in grape seed extract reduces plaque formation and resulting cognitive impairment in an animal model of Alzheimer's disease, new research shows. The study appears in the June 18 issue of The Journal of Neuroscience. Apple pectin, apple juice extracts shown to have anticarcinogenic effects on colon The apples and apple juice you consume may have positive effects in one of the most unlikely places in the body - in the colon. Winemaking waste proves effective against disease-causing bacteria in early studies A class of chemicals in red wine grapes may significantly reduce the ability of bacteria to cause cavities, according to a study published recently in the Journal of Agricultural and Food Chemistry. A 'grape' future for Alzheimer's disease research With National Alzheimer's Awareness Month upon us, attention continues to focus on new approaches to cognitive health in an aging population. Cocoa, but not tea, may lower blood pressure Foods rich in cocoa appear to reduce blood pressure but drinking tea may not, according to an analysis of previously published research in the April 9 issue of Archives of Internal Medicine, one of the JAMA/Archives journals. Mediterranean diet wards off childhood respiratory allergies A "Mediterranean" diet rich in fruits, vegetables and nuts protects against allergic rhinitis and asthma symptoms, suggests research published ahead of print in Thorax. Green tea and COX-2 inhibitors combine to slow growth of prostate cancer Drinking a nice warm cup of green tea has long been touted for its healthful benefits, both real and anecdotal. But now researchers have found that a component of green tea, combined with low doses of a COX-2 inhibitor, could slow the spread of human prostate cancer. Phenolic compounds may explain Mediterranean diet benefits Phenolic compounds in olive oil, which have antioxidant, anti-inflammatory and anti-clotting properties, may explain cardiovascular health benefits associated with the so-called Mediterranean Diet. Compound in wine reduces levels of Alzheimer's disease-causing peptides A study published in the November 11 issue of the Journal of Biological Chemistry shows that resveratrol, a compound found in grapes and red wine, lowers the levels of the amyloid-beta peptides which cause the telltale senile plaques of Alzheimer's disease. Toasty oat aroma influenced by presence of health-linked polyphenols Penn State food scientists have shown that the amount of health-linked polyphenols present during roasting or baking influences the toasty aroma developed by oats and might be used to limit the generation of off-flavors in oat products. More Polyphenol News Articles |
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