Health Benefit of Grapes : by Ray Sahelian, M.D. Health benefit of grape juice

Grape Information by Ray Sahelian, M.D. Grape Juice

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.

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 Jul;84(1):252-62. 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. CONCLUSION: 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.

Grape Research
Comparison of Cardioprotective Abilities between the Flesh and Skin of Grapes.
J Agric Food Chem. 2006 Sep 6;54(18):6613-6622. Department of Medical Pharmacology, Chemotherapy and Toxicology, Faculty of Medicine, University of Milan, Milan, Italy; C.R.A., I.V.T.P.A. (Institute of Technological Development of Agricultural Products), Milan, Italy; C.R.A., I.S.E. (Enology Experimental Institute), Velletri, Italy; C.N.R. (National Council of Research), Institute of Molecular Science and Technology, Milan, Italy; and Cardiovascular Research Center, University of Connecticut School of Medicine, Farmington, Connecticut 06030.
Recent studies have documented that grapes and grape juices are equally cardioprotective as red wine. The existing reports implicate that the skin and seeds of the grapes containing polyphenolic antioxidants are instrumental for the cardioprotective properties of grapes. The present study examines if the flesh of grapes also possesses any cardioprotective abilities. Three groups of randomly selected rats were fed, water only (control), flesh of the grapes (2.5 mg/kg b. wt.) or the skins (2.5 mg/kg b. wt.) for 30 days. The results indicate for the first time that the flesh of grapes are equally cardioprotective as skin, and 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.

Grape questions
Q. I am very interested in doing the Grape Cure for Cancer. It involves a 12 hour water fast followed by a 12 hour grape fast for six weeks. No other food in consumed. Because of the resveratrol it is supposed to be very effective in the process of cancer. I would very much like to hear your opinion.
A. We have no experience with such a grape cure for cancer fast. There are potential dangers to fasting.

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