Organic Fruit Juices Contain Up To Ten Times More Flavonoids
Filed Under News December 19, 2007
Research at Washington State University supported by The Organic Center has led to the first-ever assessment of the bioavailability of the chiral flavonoids hesperetin, naringenin, and eriodictyol — important antioxidants in citrus fruits and juices. Dr. Neal Davies leads the research team at WSU. Using sensitive techniques, they measured the levels of three flavonoids and their enantiomers in conventional and organic fruit and tomato juices, and for the first time ever, quantified both the glycoside (molecule with attached sugars) and agylcone (molecule stripped of sugars) forms of the enantiomers of these three flavonoids. Organic lemonade had ten-times the total eriocitrin (glycoside form of eriodictyol) compared to conventional lemonade, and the agylcone form had over three-times the level in conventional juice. Organic lime juice also had three-times the level of eriocitrin, compared to conventional lime juice. Organic apple juice had over three times the total hesperidin (glycoside), and almost twice the hesperetin (agylcone form). Organic grapefruit juice had about 20% less total hesperidin (glycoside), but 77% more hesperetin (agylcone). The importance of measuring both the glycoside and agylcone form of flavonoids (and other nutrients) is clear in the grapefruit juice findings. Based on the data for just the glycoside form of hesperidin, it would appear that conventional grapefruit juice contains more of this flavonoid than the organic juice that was tested. But by focusing on the more bioavailable agylcone form, the opposite conclusion would be reached. Source: J.A. Yanez et al., “Pharmacokinetics of Selceted Chiral Flavonoids: Hesperetin, Naringenin, and Eriodictyol in Rats and their Content in Fruit Juices,” Biopharmaceutics Drug Disposition, Vol. 29, pp. 63-82, September 2007
Antioxidants Help Combat Oxidative Stress and Inflammation Associated with Diabetes
Filed Under News December 19, 2007
Free radicals, also known as reactive oxygen species (ROS), are a normal consequence of cell respiration and other biological processes. Our bodies make antioxidants to neutralize ROS, and we consume other antioxidants through the diet that help neutralize free radicals and limit their damage to cell walls and DNA. Organic production increases antioxidant levels by, on average, about 30%, as shown in the Center’s State of Science Review http://www.magnet
mail1.net/ls.cfm?r=102153855&sid=3206541&m=407230&u=ORGANIC&s=
http://www.organic-center.org/science.antiox.php?action=view&report_id=3 on antioxidants. ROS damage to cells, chronic inflammation, and heart disease are among the common and costly complications of diabetes. A team of scientists in Korea have found that proanthocyanidins, antioxidants in several fruits and vegetables, substantially reduce the damage caused by ROS and inflammation in diabetic rats.
Source: Y.A. Lee et al., “Ameliorative Effects of Proanthocyanidin on Oxidative Stress and Inflammation in Streptozotocin-Induced Diabetic Rats,” Journal of Food and Agricultural Chemistry, Vol 55, November 14, 2007
More research needed for antioxidants
Filed Under News December 18, 2007
Ming Hu from the University of Houston issues “a call to arms” for more relevant research into the bioavailability and utilisation of the antioxidants, particularly polyphenols, in order to help “the successful development of polyphenols as chemopreventive agents in the future”.
A vast body of epidemiological studies has linked increased dietary intake of antioxidants from fruits and vegetables to reduced risks of a range of diseases including cancer, cardiovascular disease and diabetes.
“However, these types of research are often carried out on animals, and their effects on humans remain uncertain. A critically important scientific question is then: are these flavonoids and polyphenols as effective as people believe?” wrote Hu.
Indeed, insufficient research has been done with respect the bioavailability of these compounds, and possible interactions with pharmaceuticals, he said.
“Because these agents are targeted for disease prevention, oral administration is the only viable route, except for topical application on external organs such as skin,” he wrote. “For polyphenols to become bioavailable, the following barriers must be overcome: solubility, permeability, metabolism, excretion, target tissue uptake, and disposition.”
Moreover, animal studies have suggested that the bioavailability of typical polyphenols is around 10 per cent or less, but this can range from two to 20 per cent.
“There is an urgent need to perform systematic studies to demonstrate how changes in polyphenol structures affect solubility and dissolution rates and how various pharmaceutical excipients may be used to improve their dissolution rate,” said Hu.
Almond Phytochemicals
Filed Under News December 8, 2007
Almond’s contain phytochemicals such as sphingolipid, beta-sitosterol, daucosterol, uridine, and adenosine.
Almond also contain’s a protein called amandin. Amandin is a legumin type protein characterized by a sedimentation value of 14S. It is composed of two major types of polypeptides with estimated molecular weights of 42-46 and 20-22 kDa linked via disulfide bonds. Amandin is not a glycoprotein. Amandin-1, amandin-2, and amandin-3 are antigenically related and have similar biochemical properties.
Researchers studied the flavonol content of 16 almond varieties and they found each of the 16 seedcoat samples exhibited a unique composition. Four flavonol glycosides were identified in almond seedcoats: isorhamnetin rutinoside, isorhamnetin glucoside, kaempferol rutinoside, and kaempferol glucoside.
Almond’s are said to provide health benefits including cardiac protection and cholesterol- lowering.
Microwave Cooking Destroys Flavonoids
Filed Under News December 7, 2007
Steaming the best way to cook vegetables and microwaving them is the worst, according to a study that compared the nutrients left in broccoli cooked in different ways.
Cristina Garc’a-Viguera’s team at CEBAS-CSIC, one of Spain’s scientific research council centres, in Murcia, measured the levels of antioxidants such as flavonoids left in Broccoli after steaming, pressure cooking, boiling or microwaving. Antioxidants protect our cells from damage by mopping up highly reactive chemicals called free radicals, reducing the risk of cancer and degenerative diseases. Steaming left antioxidants almost untouched, while microwaving virtually eliminated them, the team found (Journal of the Science of Food and Agriculture, vol 83, p 1511).
Microwaves probably destroy more antioxidants because they generate higher temperatures, says Garc’a-Viguera. “Internal heating is much more damaging.”
Antioxidants May Prevent Fat Cell Formation
Filed Under News December 6, 2007
Reent research from Taiwan suggests that antioxidants put a halt to fat cell formation, at least in a laboratory.
In the study, published in the Journal of Agriculture and Food Chemistry, 15 phenolic acids and six flavonoids were exposed to mouse cells. Phenolic acids and flavonoids are classes of potent plant chemicals that exert multiple health benefits as antioxidants and anti-inflammatories. The researchers wanted to see if these antioxidants would have an affect on the formation of triglycerides, the chemical form in which most fat exists in food and in the body.
Two antioxidants in particular, o-coumaric acid and rutin, were found to inhibit the creation of triglycerides by 61 percent and 83 percent, respectively. Not only that, these same two antioxidants also increased the levels of a protein called adinopectin. This protein has been found to have protective effects against atherosclerosis.
Antioxidant Activity of Wild Strawberries
Filed Under News December 4, 2007
Dr. Shiow Y. Wang, a plant physiologist and biochemist at the U. S. Department of Agriculture’s Agricultural Research Service, led a recent study that investigated the antioxidant capacity and anticancer activity of multiple species of wild strawberries. According to Dr. Wang, “antioxidants are natural plant chemicals that play an important role in promoting human health. While we have known that wild strawberries are a good source for obtaining desirable traits to be used in breeding programs, little information was available on antioxidant activities and their inhibitory effects on the growth of cancer cells in specific species of wild strawberries.”
The study published in the Journal of the American Society for Horticultural Science found that antioxidant capacity and anti-cancer activity vary greatly among different types of wild strawberries. Researchers discovered seven types of wild strawberries that contain higher antioxidant levels and more potential to reduce cancer risk. “These seven types may be especially useful in developing cultivars with greater anticancer potential. They showed significantly greater anti-proliferation effects than other genotypes we tested”, stated Dr. Wang.
Results of the research study will be valuable to scientists, fruit breeders, and produce growers interested in producing berries that are high in antioxidants.
