Osman HE. Maalej N. Shanmuganayagam D. Folts JD. Institution
University of Wisconsin Medical School Madison, WI, 53792, USA. Title
Grape juice but not orange or grapefruit juice inhibits platelet activity in dogs and monkeys.
Journal of Nutrition. 128(12):2307-12, 1998 Dec. Abstract
Platelet aggregation (PA) contributes to both the development of atherosclerosis and acute platelet thrombus formation (APTF) followed by embolization producing cyclic flow reductions (CFR) in stenosed and damaged dog and human coronary arteries. In seven anesthetized dogs with coronary stenosis and medial damage, CFR occurred at 7 +/- 3/30 min and were abolished 127 +/- 18 min after gastric administration of 10 mL of purple grape juice/kg. Collagen-induced ex vivo whole blood PA decreased by 49 +/- 9% after the abolishment of CFR with grape juice. Ten mL of orange juice/kg (n = 5) and 10 mL of grapefruit juice/kg (n = 5) had no significant effect on the frequency of the CFR or on ex vivo PA. In vitro studies have suggested that flavonoids bind to platelet cell membranes and thus may have an accumulative or tissue-loading effect over time. To test this we fed 5 mL of grape juice/kg to 5 cynomologous monkeys for 7 d. Collagen-induced ex vivo PA decreased by 41 +/- 17% compared to control (pre-reatment) after 7 d of feeding. In the same 5 monkeys, neither 5 mL of orange juice/kg nor 5 mL of grapefruit juice/kg given orally for 7 d produced any significant change in PA. Grape juice contains the flavonoids quercetin, kaempferol and myricetin, which are known inhibitors of PA in vitro. Orange juice and grapefruit juice, while containing less quercetin than grape juice, primarily contain the flavonoids naringin, luteolin and apigenin glucoside. The flavonoids in grapes were shown in vitro to be good inhibitors of PA, whereas the flavonoids in oranges and grapefruit to be poor inhibitors of PA. The consumption of grape juice, containing these inhibitors of PA, may have some of the protection offered by red wine against the development of coronary artery disease (CAD) and acute occlusive thrombosis, whereas orange juice or grapefruit juice may be ineffective. Thus, grape juice may be a useful alternative dietary supplement to red wine without the concomitant alcohol intake.
Boss PK. Davies C. Robinson SP.
Cooperative Research Centre for Viticulture, Glen Osmond, Australia. Title
Expression of anthocyanin biosynthesis pathway genes in red and white grapes.
Plant Molecular Biology. 32(3):565-9, 1996 Nov. Abstract
The expression of seven genes from the anthocyanin biosynthesis pathway was determined in different tissues of Shiraz grapevines. All of the tissues contained proanthocyanidins, but only the berry skin accumulated anthocyanins. In most tissues, all of the flavonoid genes except UDP glucose-flavonoid 3-o-glucosyl transferase (UFGT) were expressed, but UFGT expression was only detected in berry skin. Similar patterns of expression were observed in the skin of other red grapes. In white grapes, UFGT expression was not detected. White grape cultivars appear to lack anthocyanins because they lack UFGT, although they also had decreased expression of other flavonoid pathway genes.
Zheng T. Boyle P. Willett WC. Hu H. Dan J. Evstifeeva TV. Niu S. MacMahon B.
Division of Epidemiology and Biostatistics, European Institute of Oncology, Milan, Italy.
A case-control study of oral cancer in Beijing, People's Republic of China. Associations with nutrient intakes, foods and food groups. Source
European Journal of Cancer. Part B, Oral Oncology. 29B(1):45-55, 1993 Jan. Abstract
A case-control study of oral cancer was conducted in Beijing, People's Republic of China to examine the association between dietary nutrient intake and risk of oral cancer, both in terms of estimated intake of nutrients and micro-nutrients, and in terms of specific foods and food groups. The study was hospital-based and controls were hospital in-patients matched for age and sex with the cases. The response rate for cases and controls was 100% and 404 case/control pairs were interviewed. The results suggest that increased protein and fat intake are related to a decreased risk of oral cancer. Carbohydrate intake, however, showed a moderate increased risk for oral cancer. Total carotene intake and carotene intake from fruits and vegetables are inversely associated with risk of oral cancer. A similar pattern was observed for dietary vitamin C intake. Dietary fibre derived from fruits and vegetables showed a strong negative association with oral cancer risk, but fibre derived from other sources did not exhibit any protective effect. At the level of foods and food groups, increased consumption of fresh meat, chicken and liver was significantly associated with a reduction in oral cancer risk: the tests for trend were all statistically significant at the P < 0.01 level. Consumption of common carp, hairtail, shrimp and lobster were also associated with decreased risk. Risk was found to increase with increasing consumption of millet and corn bread (P < 0.01) but to decrease with increasing consumption of rice (P < 0.01). Increased consumption of grapes, bananas, oranges, tangerines, peaches and pears were associated with reduced risk.(ABSTRACT TRUNCATED AT 250 WORDS)
Bolton RP. Heaton KW. Burroughs LF.
The role of dietary fiber in satiety, glucose, and insulin: studies with fruit and fruit juice.
American Journal of Clinical Nutrition. 34(2):211-7, 1981 Feb. Abstract
Healthy volunteers ingested sugar-equivalent meals of oranges and orange juice and of grapes and grape juice. Satiety, assessed by two subjective scoring systems, was greater after whole fruit than after juice and the return of appetite was delayed. With oranges, as previously reported with apples, there was a significantly smaller insulin response to fruit than to juice and less postabsorptive fall in plasma glucose. With grapes, the insulin response to the whole fruit was, paradoxically, more than that to the juice, while postabsorptive glucose values were similar. The glucose in grapes appeared to be more insulinogenic than that in oranges and apples. Conversely, grape juice evoked less insulin than expected, possibly because its high osmolality delayed gastric emptying. However, diluting it did not increase its insulinogenicity. The plasma insulin and glucose responses to fruit appear to depend on the fiber as well as the glucose content of the fruit.