Grape Juice, Purple

Scientific Name(s): Vitis vinifera L., V. labrusca L., V. rotundifolia Michx. Family: Vitaceae

Common Name(s): European or “Old World” grapes (most common; 95% of grapes) ( V. vinifera ); American bunch grapes ( V. labrusca ); muscadine grapes ( V. rotundifera )

Uses of Grape Juice, Purple

Flavonoids in purple grape juice possess beneficial cardiac effects. Grape juice also has antiviral and antibacterial effects and is mildly laxative.

Grape Juice, Purple Dosing

There is no clinical evidence to support specific dosage recommendations for purple grape juice.

Contraindications

Contraindications have not yet been identified.

Pregnancy/Lactation

Generally recognized as safe or used as food. Avoid dosages above those found in food because safety and efficacy are unproven.

Grape Juice, Purple Interactions

None well documented.

Grape Juice, Purple Adverse Reactions

Research reveals little or no information regarding adverse reactions with the use of purple grape juice.

Toxicology

Research reveals little or no information regarding toxicology with the use of purple grape juice.

Botany

Grapes grow in bunches (from 6 to 300) on woody, climbing vines. These fruits come in a variety of colors, including black, blue, golden, green, red, white, and purple. Certain flavonoids present in the purple grape varieties possess beneficial actions not seen in the others (see Wine monograph). V. vinifera is a deciduous climber with several stems, tendrils, clusters of pale, green flowers, and palm-shaped leaves. In addition to the kinds of grapes listed above, French hybrid varieties of grapes exist that were developed mainly for wine making. Grapes are native to southern Europe and western Asia but are cultivated in warm temperate regions throughout the world. 1 , 2 Grape juice is the fluid expressed from ripened grapes. They are passed through a separator, which removes the skins, stems, seeds, and pulp. The juice then is treated and pasteurized. 1

History

Grape leaves have been seen in fossils dating back to prehistoric times. Grapes were domesticated in western Asia before 5000 BC and have been mentioned in biblical writings and depicted in tomb paintings dating back to 2375 BC. Circa 1635, Jesuit fathers brought Spanish grapes to Mexico, establishing vineyards in what is now Socorro, New Mexico, the area of the earliest planting of grapes in the United States. 1 In 1652, Nicholas Culpeper recommended grapes as a mouthwash. 2 In the 1850s, California became involved in grape culture. 1 In 1927, physician A.M. Liebstein mentioned grapes as being beneficial for dyspeptic and febrile conditions, liver and kidney ailments, tuberculosis, hemorrhoids, varicose veins, osteomyelitis, gangrene, and cancer. The Grape Cure (1928, Johanna Brandt) claimed that grapes had cured the author's abdominal cancer. 3 Modern scientific studies demonstrate a variety of beneficial effects from grapes.

Chemistry

Grapes are ≈ 80% water and contain 70 calories/100 g. The sugar (carbohydrate) content is ≈ 16%. 1 Commercial grape juice is lower in sucrose than other fruit juices. 4 Other sugars, amino acids, and organic acids in grape juice and wines have been detected. 5 The amino acid arginine has been separated from grape juice. 6 Grapes contain tartaric and carboxylic acids, including malic, citric, lactic, succinic, and shikimic acids. 2 , 7 Vitamins A, B ₁ , B ₂ , and C also are present in grapes, as are minerals including chromium and potassium. 1 , 2 Anthocyanins are found in grapes with red pigments, 2 as well as in other pigmented fruits such as the blackberry, strawberry, and blueberry. 8 A review discussing anthocyanins in grapes, juices, and wines is available. 9 Flavonoids including quercetin, catechins, myricetin, and kaempferol are the more important constituents in purple grape juice and red wine. 10 Catechin concentrations are substantial in red wine (27 to 96 mg/L) but low to negligible in white wine and commercially available grape juices tested in another report. 11 Other constituents found in grapes include tannins, inositol, choline, and pectin. 2 Glutathione and thiol-containing compounds have been found in the juice. 12 Isomers of resveratrol in grape juice and wine also are present, 13 as are antioxidants. 14

Grape Juice, Purple Uses and Pharmacology

In general, grapes are nourishing and mildly laxative, offering support in the GI tract and liver. Red grape leaves are known to be astringent and anti-inflammatory. Red leaves and grapes are used in the treatment of varicose veins, hemorrhoids, and capillary fragility. 2 Grape juice is high in chromium, a mineral that is part of the glucose tolerance factor, which works with insulin to promote utilization of sugar. 1

Cardiovascular function

Attention has focused on purple grape juice and its beneficial effects in heart health. Certain flavonoids in purple grape juice and red wines may be responsible for keeping heart-damaging blood clots from forming. Aspirin is used for this purpose as well, but its effects against platelet aggregation are negated by adrenaline, which is released under stressful situations. Flavonoids are not affected by adrenaline, and thus are still available to prevent clot formation. 15

Pure grape juice's ability to slow onset of oxidation, reduce platelet activity, and increase nitric oxide production collectively may contribute to healthy cardiovascular function. 16

Animal data

Research reveals no animal data in regards to the use of purple grape juice for cardiovascular activity.

Clinical data

An older report demonstrates anti-platelet aggregation and thrombin production to be reduced by grape juice and red wine. However, the study suggests that the ethanol contained in the wine is the dominant anti-aggregatory component because of its greater ability to prevent platelet aggregation as compared with grape juice. 17 In a randomized, crossover study involving 10 patients, purple grape juice consumption for 1 week reduced the whole blood platelet aggregation response by 77% vs orange and grapefruit juices, confirming purple grape juice's effects in decreasing risk of coronary thrombosis and MI because of increased polyphenolic concentration present (≈ 3 times more than the other juices). 17 Another report in 15 coronary artery disease (CAD) patients concluded that short-term ingestion of purple grape juice improved endothelium-dependent vasodilation and prevented LDL oxidation, reducing negative cardiovascular outcomes. This was shown to be caused by flavonoid components present. 10 Compared with controls, 14 patients with CAD, consuming 7 to 10 mL/kg/day of purple grape juice for 14 days, demonstrated increased lag time measurements, which determine cholesterol oxidation time. (The longer the lag time, the slower the onset of oxidation.) It was concluded that this delay in oxidation of LDL cholesterol is beneficial because it is usually a key contributor to the development of atherosclerosis.

Other uses

Grape juice possesses marked antiviral properties in vitro against such viruses as poliovirus and herpes simplex virus. Tannins may be responsible for these effects. Studies also have demonstrated grape juice as being antibacterial, drastically reducing tooth decay in animals. The caffeic acid constituent prevents cancer in animals. Raisins are linked to lower rates of cancer deaths in elderly patients. 3

Dosage

There is no clinical evidence to support specific dosage recommendations for purple grape juice.

Pregnancy/Lactation

Generally recognized as safe or used as food. Avoid dosages above those found in food because safety and efficacy are unproven.

Interactions

None well documented.

Adverse Reactions

Research reveals little or no information regarding adverse reactions with the use of purple grape juice.

Toxicology

Research reveals little or no information regarding toxicology with the use of purple grape juice.

Bibliography

1. Ensminger A, et al. Foods & Nutrition Encyclopedia, 2nd ed. (Vol.1). Boca Raton, FL: CRC Press;1994:1093-99.
2. Chevallier A. The Encyclopedia of Medicinal Plants . New York, NY: DK Publishing;1996:281.
3. Carper J. The Food Pharmacy . New York, NY: Bantam Books;1988:211-12.
4. Yoon J, et al. Chemometric aspects of sugar profiles in fruit juices using HPLC and GC. Bull Korean Chem Soc 1997;18(7):695-702.
5. Linget C, et al. Online dialysis with HPLC for the automated preparation and analysis of amino acids, sugars, and organic acids in grape juice and wines. Analusius 1998;26(1):35-39.
6. Austin K, et al. Spectrophotometric assay for arginine in grape juice and must. Am J Enol Vitic 2000;51(3):227-232.
7. Fuleki T, et al. Carboxylic acid composition of authentic varietal and commercial grape juice. J AOAC Int 1993;76(3):591-600.
8. Koswig S, et al. HPLC method for determination of anthocyanins in colored juices and other pigmented foods. Fluess Obst 1995;62(4):125,128-30.
9. Mazza G. Anthocyanins in grapes and grape products. Crit Rev Food Sci Nutr 1995;35(4):341-71.
10. Stein J, et al. Purple grape juice improves endothelial function and reduces the susceptibility of LDL cholesterol to oxidation in patients with coronary artery disease. Circulation 1999;100(10):1050-55.
11. Arts I, et al. Catechin contents of foods commonly consumed in the Netherlands. Part 2. Tea, wine, fruit juices, and chocolate milk. J Agric Food Chem 2000;48(5):1752-57.
12. Park S, et al. Automated HPLC analysis of glutathione and thiol-containing compounds in grape juice and wine using pre-column derivatization with fluorescence detection. Food Chem 2000;68(4):475-80.
13. Soleas G, et al. A derivatized gas chromatographic-mass spectrometric method for the analysis of both isomers of resveratrol in juice and wine. Am J Enol Vitic 1995;46(3):346-52.
14. Wang H, et al. Total antioxidant capacity of fruits. J Agric Food Chem 1996;44(3):701-05.
15. http://www.lifeplusvitamins.com/heart.htm .
16. http://www.bevnetmarketplace.com/news/99/03-11-1999-welchs.asp .
17. Pace-Asciak C, et al. Wines and grape juices as modulators of platelet aggregation in healthy human subjects. Clin Chim Acta 1996;246(1,2):163-82.
18. Keevil J, et al. Grape juice, but not orange juice or grapefruit juice, inhibits human platelet aggregation. J Nutr 2000;130(1):53-56.

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