April 20, 2007
Meta-analysis finds antioxidant supplementation safe during cancer therapy
The January/February and March/April 2007 issues of the journal Alternative Therapies published a two part article by a team at the Simone Protective Cancer Institute in Lawrenceville, New Jersey, which concluded that, contrary to long-held beliefs, antioxidant and other nutritional supplementation during chemotherapy or radiation does not interfere with these treatments.
"A single, front-page interview in The New York Times in 1997, which was not based on published scientific work, and a single research paper involving mice, along with a press release by its author in 1999, led to the erroneous notion that vitamin C interferes with chemotherapy and radiation in humans," the authors write. "This notion soon applied to all antioxidants as physicians, patients, the media, the American Cancer Society, and scores of websites took the same position without reviewing the scientific evidence."
For their meta-analysis, oncologist Charles B. Simone, MD, and colleagues identified 50 human studies that included a total of 8,251 participants involving the use of chemotherapy and/or radiation concurrently with dietary supplements. They discovered that antioxidants and other supplements failed to interfere with the treatments and were actually found to enhance them. In 47 of these studies, supplements were associated with protection of normal tissue and a reduction of side effects, and in 15 studies, 3,738 subjects experienced increased survival.
The authors explain that, due to a loss of the homeostasis control mechanism for the uptake of antioxidants, cancer cells accumulate large amounts of the nutrients, while healthy cells do not have this membrane defect. This accumulation decreases the oxidative reactions needed for the generation of the cells' energy. Additionally, the nutrients elicit other effects on cancer cells unrelated to their antioxidant activity.
The authors concluded that "Antioxidant and other nutrient food supplements are safe and can help to enhance cancer patient care."
Friday, April 27, 2007
Wednesday, April 04, 2007
Pine bark extract shows promise for slowing sugar uptake
By Stephen Daniells
2/9/2007 - Extracts from French maritime pine bark may inhibit an enzyme linked to glucose absorption 190 times more than a synthetic medication, says new research from Germany that could offer significant benefits for diabetics if the results can be translated from the lab to humans.The results of the new study, published on-line in the Elsevier journal Diabetes Research and Clinical Practice, add to a growing body of research reporting anti-diabetic effects of the pine bark extract, Pycnogenol.
"Diabetes mellitus type II is a serious disease with rising prevalence," said lead researcher Dr. Petra Hogger. "This study is crucial for those suffering with the disease because it affirms that Pycnogenol is more effective than [a] prescription medication and supports the abundance of other research done on Pycnogenol and diabetes."
An estimated 19 million people are affected by diabetes in the EU 25, equal to four per cent of the total population. This figure is projected to increase to 26 million by 2030.
In the US, there are over 20 million people with diabetes, equal to seven per cent of the population. The total costs are thought to be as much as $132 bn, with $92 bn being direct costs from medication, according to 2002 American Diabetes Association figures.
Hogger and co-researcher Angelika Schafer from Wurzburg University tested Pycnogenol, a green tea extract (Emil Flachsmann) and the synthetic compound acabrose (Glucobay, Bayer Vital) for their ability to inhibit alpha-glucosidase, an enzyme found in the large intestine that is involved in the metabolism of carbohydrates and the production of glucose.
By inhibiting the activity of the enzyme it could be possible to prevent typical high-glucose peaks in the blood stream after a meal.
The in vitro study used an assay of alpha-glucosidase activity with equal concentrations of each sample and report that the most potent inhibition of the alpha-glucosidase was achieved by the pine bark extract (quantity required 50 per cent inhibition five micrograms per millilitre), followed by the green tea extract (20 micrograms per millilitre) and finally the acarbose (one milligram per millilitre).
"Since the alpha-glucosidase enzymes are located in the duodenum the intact pine bark extract constituents could exert inhibitory effects on alpha-glucosidase before a secondary metabolism of the procyanidin oligomers by bacteria occurs of the lower intestinal tract," wrote the researchers.
"Our results contribute to the explanation of clinical anti-diabetic effects of Pycnogenol," they said.
To identify which compounds in Pycnogenol may be behind the inhibiting effects, the researchers tested four different fractions (phenol carbonic acids and monomeric polyphenols; dimeric and trimeric procyanidins; tetrameric up to hexameric procyanidins; and higher oligomeric compounds).
The latter of these fractions inhibited the enzyme's activity by 94 per cent.
"The results obtained assign a novel, local effect to oligomeric procyanidins and contribute to the explanation of glucose-lowering effects of Pycnogenol observed in clinical trials with diabetic patients," wrote the researchers.
The actual mechanism by which these oligomeric procyanidins inhibit alpha-glucosidase is not clear, and more research is needed to elucidate these effects. Additional in vivo studies are needed to support these effects.
Horphag Research, manufacturer of Pycnogenol, has been very active in sponsoring and supporting studies into the potential health benefits of the pine bark extract and was the funding source behind this latest study.
The first research was conducted on the ingredient 35 years ago. Victor Ferrari, research chief operating officer and executive vice president of Horphag Research, told NutraIngredients recently that the company ploughs $1.5m - "most of its profits" - into research each year.
The product is extracted from the bark of the Maritime pine that grows on the southern coast of France, and is currently used in over 400 dietary supplements, multi-vitamins and health products.
Source: Diabetes Research and Clinical PracticePublished on-line ahead of print, doi: 10.1016/j.diabres.2006.10.011"Oligomeric procyanidins of French maritime pine bark extract (Pycnogenol) effectively inhibit alpha-glucosidase"Authors: A. Schafer, P. Hogger
2/9/2007 - Extracts from French maritime pine bark may inhibit an enzyme linked to glucose absorption 190 times more than a synthetic medication, says new research from Germany that could offer significant benefits for diabetics if the results can be translated from the lab to humans.The results of the new study, published on-line in the Elsevier journal Diabetes Research and Clinical Practice, add to a growing body of research reporting anti-diabetic effects of the pine bark extract, Pycnogenol.
"Diabetes mellitus type II is a serious disease with rising prevalence," said lead researcher Dr. Petra Hogger. "This study is crucial for those suffering with the disease because it affirms that Pycnogenol is more effective than [a] prescription medication and supports the abundance of other research done on Pycnogenol and diabetes."
An estimated 19 million people are affected by diabetes in the EU 25, equal to four per cent of the total population. This figure is projected to increase to 26 million by 2030.
In the US, there are over 20 million people with diabetes, equal to seven per cent of the population. The total costs are thought to be as much as $132 bn, with $92 bn being direct costs from medication, according to 2002 American Diabetes Association figures.
Hogger and co-researcher Angelika Schafer from Wurzburg University tested Pycnogenol, a green tea extract (Emil Flachsmann) and the synthetic compound acabrose (Glucobay, Bayer Vital) for their ability to inhibit alpha-glucosidase, an enzyme found in the large intestine that is involved in the metabolism of carbohydrates and the production of glucose.
By inhibiting the activity of the enzyme it could be possible to prevent typical high-glucose peaks in the blood stream after a meal.
The in vitro study used an assay of alpha-glucosidase activity with equal concentrations of each sample and report that the most potent inhibition of the alpha-glucosidase was achieved by the pine bark extract (quantity required 50 per cent inhibition five micrograms per millilitre), followed by the green tea extract (20 micrograms per millilitre) and finally the acarbose (one milligram per millilitre).
"Since the alpha-glucosidase enzymes are located in the duodenum the intact pine bark extract constituents could exert inhibitory effects on alpha-glucosidase before a secondary metabolism of the procyanidin oligomers by bacteria occurs of the lower intestinal tract," wrote the researchers.
"Our results contribute to the explanation of clinical anti-diabetic effects of Pycnogenol," they said.
To identify which compounds in Pycnogenol may be behind the inhibiting effects, the researchers tested four different fractions (phenol carbonic acids and monomeric polyphenols; dimeric and trimeric procyanidins; tetrameric up to hexameric procyanidins; and higher oligomeric compounds).
The latter of these fractions inhibited the enzyme's activity by 94 per cent.
"The results obtained assign a novel, local effect to oligomeric procyanidins and contribute to the explanation of glucose-lowering effects of Pycnogenol observed in clinical trials with diabetic patients," wrote the researchers.
The actual mechanism by which these oligomeric procyanidins inhibit alpha-glucosidase is not clear, and more research is needed to elucidate these effects. Additional in vivo studies are needed to support these effects.
Horphag Research, manufacturer of Pycnogenol, has been very active in sponsoring and supporting studies into the potential health benefits of the pine bark extract and was the funding source behind this latest study.
The first research was conducted on the ingredient 35 years ago. Victor Ferrari, research chief operating officer and executive vice president of Horphag Research, told NutraIngredients recently that the company ploughs $1.5m - "most of its profits" - into research each year.
The product is extracted from the bark of the Maritime pine that grows on the southern coast of France, and is currently used in over 400 dietary supplements, multi-vitamins and health products.
Source: Diabetes Research and Clinical PracticePublished on-line ahead of print, doi: 10.1016/j.diabres.2006.10.011"Oligomeric procyanidins of French maritime pine bark extract (Pycnogenol) effectively inhibit alpha-glucosidase"Authors: A. Schafer, P. Hogger
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