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Diabetes Type 2 Diabetes and Glycemic Response to Grapes or Grape Products.
Specialty: Emergency Medicine
Posted Mar 03 2012 12:00am
Unable to locate my source for the comparison of varietals with regard to the US Davis piece. But this may be of interest:
David M. Goldberg,
Eleftherios P. Diamandis,
and Andrew L. Waterhouse
A Global Survey of Trans-Resveratrol Concentrations in Commercial Wines Am. J. Enol. Vitic. 1995 46:159-165
Abstract:Using a solid-phase extraction followed by direct-injection gas chromatography-mass spectrometry, the concentration of trans-resveratrol was measured in a representative selection of wines from most of the prominent wine-producing countries and regions of the world. With the exception of Swiss and German wines, virtually all of the white wines tested had trans-resveratrol concentrations <0.1 mg/L. Consistently high concentrations were measured in wines from Pinot noir, irrespective of origin. On the other hand, Cabernet Sauvignon wines covered a wide range of concentrations, with relatively high values in those from cool-climate countries such as Ontario and the Bordeaux region of France, whereas such wines from warmer climates such as California, South America, and Australia tended to have much lower concentrations. Differences between the communes of Bordeaux and Burgundy were noted, with Cotes de Nuits wines having higher concentrations than those of Cotes de Beaune, and in Bordeaux, wines of the Medoc, St. Emilion, and Pomerol had lower concentrations than those found in wines from other communes. Among the other prominent wine-producing regions, wines from Italy, Spain and Portugal tended to have low concentrations in line with their relatively warm and dry climatic conditions, but those of the Rhone Valley where the climate is similar had relatively high trans-resveratrol concentrations. The higher concentrations reported in this study compared with three earlier reports could be due to the quantitative recovery inherent in the solid-phase extraction used in the present assay, and/ or losses occurring during organic phase extraction in the latter.
“Resveratrol improves health and survival of mice on a highcalorie diet”By: J. Baur and 26 other authors (UC Davis)In: Nature. 444:337-342. 2006
Here are the highlights of the original “Resveratrol paper”, the one that shook the wine industry last December and got everyone talking about the health benefits of wine. So, judge for yourself! You can also choose to skip this one, as it deals with health -not winemaking or grapegrowing- even if this type of publicized research does impact consumers’ attitudes towards wine. · How to eat more healthily is a “hot topic” for medical science these days. Researchers have discovered a category of proteins, called sirtuins, that seem to regulate the physiological adaptations of mammals to a low-calorie diet (caloric restriction). When they screened a large amount of compounds in search for molecules able to enhance sirtuin production, they stumbled upon one particular molecule , produced by a variety of plants in response to stress, which was particularly potent: resveratrol. [Editor’s note: In fact, the authors pulled two enhancing molecules out of some 20,000 tested. The fact that, out of such a vast variety of chemical structures, these two molecules happened to be in the same compound category- polyphenolswas what triggered the authors to expand their health research in the direction of phenolic comopunds].· Since experiments with simple organisms ( yeast, fruit flies and fish) showed that resveratrol was effective in extending their lifespan and health, researchers asked whether it could have similar effects in mice. Could resveratrol shift the physiology of mice on a high-calorie diet to that of a standard diet and provide the associated health benefits without the mice having to reduce calorie intake?· To find out, 1 year-old mice were provided a standard diet (SD), or a high-calorie diet of which at least 60% of calories came from fat (HC). To each of the diets, they added resveratrol: standard diet + resveratrol (SDR) and high-calorie diet + resveratrol (HCR). The researchers tested two concentrations of resveratrol, but because the effects were more prominent in the higher dose (22 mg/kg/day), the results presented here refer to this high dose.· 1) Increased survival. At 15 months of age, the survival curves of the HC (high-calorie diet) and HCR (high-calorie diet + resveratrol) groups began to diverge. At 2 years of age, resveratrol had reduced death from the HC diet mice by a statistically significant 30%. In addition to lifespan, researchers wondered whether “quality of life” was maintained as well. In mice, you do that by measuring balance and motor coordination. So they tested the ability of mice to perform on a rotarod (those rods you see hanging from the cage where mice run endlessly without going anywhere). Surprisingly, resveratrol-fed mice improved their motor skills as they aged, to the point of being undistinguishable from the SD group. Researchers made sure this was not just due to the fact that resveratrol-fed mice weighed less, as they found no correlation between rotarod performance and body weight.· 2) Decreased diabetes. In humans, high-calorie diets cause increased glucose and increased insulin, leading to diabetes. The HC mice had increased plasma levels of both glucose and insulin, as well as other markers that predict the onset of diabetes. In contrast, the HCR group had much lower levels, paralleling the SD group. Also, we know that when mice are fed high doses of glucose, blood glucose levels do not Summary 74remain high for more than 60 minutes in young mice, even though a longer persistence is typical in older mice. The persistence of glucose and insulin in blood was significantly decreased in the resveratrol-fed HC mice. The authors go on next about the potential mechanism involved.· 3) Decreased organ pathology. At 18 months of age, the high-calorie diet greatly increased the size and weight of the mice livers, and resveratrol prevented these changes. Histological examination revealed loss of cellular integrity and accumulation of large lipid droplets (“fatty liver”) in the HC but not the HCR groups. Pancreas damage was also elevated in the high calorie group but not the resveratrol-fed group. Other organs studied did not show differences.· 4) Increased mitochondria number. Mitochondria are particles within the cells (organelles) where food molecules are converted into energy; they are the “cellular power plants”. There is evidence that exercise and reduced caloric intake increase hepatic mitochondrial number, so the authors wondered whether resveratrol might produce the same effect. The answer is yes: the livers of resveratrol-fed mice had considerably more mitrochondria than those of HC controls. To their surprise, they also noticed less (not more) mitochondrial genes being activated. So, even though mitochondria l numbers are higher in a resveratrol-rich diet, their turnover is less.· 5) Me tabolic pathway analysis. Through RNA hybridization experiments, the researchers looked at what genes had the highest levels of expression in the mice liver cells. They found that resveratrol caused a significant alteration of 127 pathways! These included the well-known TCA (tri-carboxylic acid) cycle, glycolysis and sterol biosynthesis pathways. With the help of databases, the authors went on to compare the pathway changes common to a caloric -reduced diet and a resveratrol diet. Could this reveal those pathways common to the enhancement of health and longevity? Based on their results, the authors encourage further studies in this direction. In conclusion, resveratrol was able to shift the physiology of mice consuming excess calories towards that of mice on a standard diet, improving their health, as indicated by longer survival, better motor function, reduced diabetes, decreased organ pathology, and higher mitochondrial number. The 27 authors end their article with the following quote: “Resveratrol - and molecules with similar properties- might be valuable tools in the search for key regulators of energy balance, health and longevity […] This study shows that a small molecule that can be administered orally at doses achievable in humans can safely reduce many of the negative consequences of excess caloric intake, with an overall improvement in health and survival”. As we know, red wine is a source of resveratrol. In the next summary, we will look at levels of resveratrol in wines.Author: Bibiana Guerra, Editor: Kay Bogart. This summary series funded by J. Lohr Vineyards & Wines.
Polyphenols - thought to be good guys
Polyphenols are anti-oxidants. The category includes tannins and are thus generally higher in red wines than in white. All the reds tested are high in polyphenols, with Rodney Strong, Beringer Founders, and BV Coastal standing out from the rest. All the whites are low in polyphenols, although Lindemans, Kendall Jackson, and Duboeuf have more than the others.
Catechins - thought to be good guys
Catechins, anti-oxidants that are a sub-class of polyphenols, are also more prevalent in red wines than whites. Blackstone, Yellow Tail, Columbia Crest, and Clos du Bois have the highest levels among the reds. Lindemans and Woodbridge have relatively high levels for white wines.
Resveratrol - clearly a good guy Resveratrol is another important anti-oxidant. Several studies show that it reduces “bad” cholesterol and increases “good” cholesterol. Resveratrol is generally higher in red wines than in whites. Among the reds, Concha y Toro is by far the highest. Clos du Bois, Rosemount, and Yellow Tail are also high. BV Coastal and Beringer Founders are very low. Among the whites, Bella Sera is surprisingly high, surpassing many of the red wines.
see ranking (Res) below:
| ||Actual %||Labeled||%||ppm.||mg/gram||mg/175g||mg/liter|
|RED WINES TESTED|| || || || || || || |
|Yellow Tail Merlot||11.1||13.5||0.5||103||3.26||102.4||2.00|
|Rosemount Shiraz||10.9||14||0.2||104||3.22|| 84.7||2.01|
|Columbia Crest Merlot/Cab||10.8||13||0|| 99||3.20|| 93.6||0.60|
|Clos du Bois Merlot||10.8||13||0||140||3.24|| 93.1||2.28|
|Beringer Founders Cab||10.5||13.3||0||198||3.62|| 83.6||0.39|
|BV Coastal Cab||10.5||13||0||122||3.40|| 69.5||0.43|
|Rodney Strong Cabernet||10.5||13.8||0||140||3.76|| 77.3||1.19|
|Concha y Toro Merlot||10.3||13||0.4||231||2.77|| 78.4||5.95|
| ||Actual %||Labeled||%||ppm.||mg/gram||mg/175g||mg/liter|
|WHITE WINES TESTED|| || || || || || || |
|Kendall Jackson VR Chard||11.0||13.5||0.6||201||0.48||26.4||0.22|
|Ch. St. Michelle Chard||10.8||13||0.1||208||0.40||39.5||0.09|
|Lindemans Bin 65 Chard||10.7||13.5||0.3||241||0.52||58.9||0.34|
|Corbett Canyon Chard||10.7||13||0.6||174||0.36||27.9||0.09|
|Glen Ellen Chard||10.6||13||0.5||154||0.30||27.9||0.09|
|E & J Gallo Chard||10.6||13.5||0.7||153||0.27||15.4||0.09|
|Duboueuf Francais Blanc||10.4||12||0||287||0.47||28.5||0.29|
|Sutter Home Chard||10.0||13||0.9||205||0.42||36.1||0.09|
|Bella Serra Pinot Grigio|| 9.7||12||0.3||308||0.34||13.5||1.66|
|Bolla Soave|| 9.7||12||0.2||199||0.30||9.8||0.16|
|Cavit Pinot Grigio|| 9.6||12||0.4||276||0.35||14.4||0.09|
|Almaden Mt. Chablis|| 9.4||11.5||0.8||233||0.33||7.3||0.09|
|Franzia Chablis (5L box)|| 8.8||11||1.1||212||0.35||10.2||0.09|
|Livingston Cellars Chablis|| 8.4||10.5||1.1||240||0.33||10.7||0.09|
|Carlo Rossi Chablis|| 8.2||10.5||1.6||172||0.32||15.2||0.09|
and this from Dr. Sahelian's site:
Grape health benefit Information, juice content of resveratrol and nutritional composition by Ray Sahelian, M.D.
Grapes are one of the most valued conventional fruits, worldwide. The flesh of grapes may be just as heart healthy as the skin. Does this mean that white wine offers as good cardiovascular protection as red wine? Researchers prepared grape skin and grape flesh extracts from four varieties of red grape and tested their cardioprotective effects in rats. They found that the flesh extract was just as protective as the skin extract. The skin of red grapes is a rich source of anthocyanins, potent antioxidants that contribute to the red color of the fruit. Red grapes are usually crushed whole, meaning the anthocyanins are transferred to resulting wine and juice. To make most white wine or white grape juices however the skins are separated from the flesh. That situation led to the conventional belief that red wines and red grape juice are healthier for the heart than white. It's possible that the antioxidant potential of skin and flesh of grapes are comparable with each other despite of the fact that flesh does not possess any anthocyanin activities. While grape skin has anthocyanin concentrations of about 128 milligrams per 100 grams, the flesh contains no such compounds. However, the radical scavenging abilities of both the flesh and skin extracts appear to be the same. The flesh of grapes contain polyphenols, but not of the anthocyanin type. Significant concentrations of caffeic acid, caftaric acid, and coutaric acid have been reported. Such compounds are also present in white grape varieties. Several organic acids and polyphenols possessing potent antioxidant activities present in the flesh of grapes are also found in white wines.
Grapes have a very important compound called resveratrol which has shown anti-aging benefit in rodent studies.
Grape juice benefit for heart
Grape juice seems to have the same protective effect against heart disease as red wine does. Researchers at the Universite Louis Pasteur de Strasbourg examined the effect on the heart of Concord grape juice. Dr. Valerie Schini-Kerth and her team found that polyphenols in Concord grape juice activate endothelial cells to produce nitric oxide, which helps to protect against cardiovascular disease and to maintain healthy blood vessels and blood pressure.
Red wine and certain types of grape juice have high levels of polyphenols, which block the production of a protein linked to cardiovascular disease -- the number one killer in many Western countries. Heart and vascular problems develop when endothelial cells that make up blood vessels do not work properly. Polyphenols work the same way in red wine and in grape juice. The amount of polyphenols in grape juice, as in red wine, depends on the type of grape used and how it is processed. This research was partly funded by Welch Foods Inc., a leading producer of grape juice.
April 2009 - E. Mitchell Seymour, at Michigan State University, studied the effect of regular table grapes -- a blend of green, red, and black grapes -- that were mixed into the rat diet in a powdered form, as part of either a high- or low-salt diet. Comparisons were made between rats consuming the grape powder and rats that received a mild dose of the common blood pressure drug hydrazine. After 18 weeks, the rats that received the grape-enriched diet powder had lower blood pressure, better heart function and fewer signs of heart muscle damage than rats that ate the same salty diet but didn't receive grapes. Rats that received the blood pressure medicine, hydrazine, along with a salty diet also had lower blood pressure, but their hearts were not protected from damage as they were in the grape-fed group. The study was presented at the 2009 Experimental Biology convention in New Orleans.
Grape Juice Benefit
Concentrated red grape juice exerts antioxidant, hypolipidemic, and antiinflammatory effects in both hemodialysis patients and healthy subjects.
Am J Clin Nutr. 2006. Servicio de Bioquimica-Investigacion, Hospital Ramon y Cajal, Madrid, Spain.
Patients treated with hemodialysis frequently experience cardiovascular complications attributed, among other causes, to dyslipidemia, increased oxidative stress, and inflammation. The aim of the study was to study the effects of dietary supplementation with concentrated red grape juice, a source of polyphenols, on lipoprotein profile, antioxidant capacity, LDL oxidation, and inflammatory biomarkers. Twenty-six patients receiving hemodialysis and 15 healthy subjects were instructed to drink 100 mL concentrated red grape juice /d for 14 d. Blood was drawn at baseline, twice during concentrated red grape juice supplementation, and twice during the 6-mo follow-up period. As a control, 12 other randomly recruited hemodialysis patients not receiving concentrated red grape juice were studied. Lipids, apolipoproteins, oxidized LDL, and antioxidant vitamins were measured in plasma. The bioavailability of concentrated red grape juice polyphenols was assessed in healthy subjects. RESULTS: The maximum plasma concentration of quercetin was achieved 3 h after concentrated red grape juice ingestion, which indicates that supplement-derived polyphenols are rapidly absorbed. In both healthy subjects and hemodialysis patients, concentrated red grape juice consumption increased the antioxidant capacity of plasma without affecting concentrations of uric acid or ascorbic acid; reduced the concentration of oxidized LDL; and increased the concentration of cholesterol-standardized alpha-tocopherol. concentrated red grape juice supplementation also caused a significant decrease in LDL-cholesterol and apolipoprotein B-100 concentrations, while increasing the concentrations of HDL cholesterol and apolipoprotein A-I. In a further study in hemodialysis patients, concentrated red grape juice supplementation for 3 wk significantly reduced plasma monocyte chemoattractant protein 1, an inflammatory biomarker associated with cardiovascular disease risk. Dietary supplementation with concentrated concentrated red grape juice improves the lipoprotein profile, reduces plasma concentrations of inflammatory biomarkers and oxidized LDL, and may favor a reduction in cardiovascular disease risk.
Dear Mr. Saleeby,