Intake Of Grape Juice Research Articles

Intake of Purple Grape Juice as a Hepatoprotective Agent in Wistar Rats

Grape juice is a source of polyphenols, as catechin, anthocyanidins, resveratrol, and others. Some health benefits have been attributed to these compounds (e.g., antioxidant and antitumorigenic properties). In this study, we investigated the possible antioxidant activity of two different grape juices: organic purple grape juice and conventional purple grape juice. The antioxidant activity of both grape juices was evaluated by an animal model of three groups: control and organic and conventional juices. After 30 days, all animals were sacrificed, and blood and liver were collected to evaluate lipid peroxidation level (thiobarbituric acid-reactive substances [TBARS] assay), protein oxidative level (carbonyl assay), and catalase (CAT) and superoxide dismutase (SOD) activities. The group treated with organic grape juice showed the highest SOD and CAT activities in both plasma and liver when compared with the conventional and control groups (P < .05). In plasma, we observed a positive correlation among SOD and CAT activities, resveratrol, and all anthocyanin contents, suggesting that these polyphenols may be, at least in part, responsible for this increased antioxidant defense. The grape juices were capable of reducing carbonyl and lipid peroxidation levels in plasma and liver. However, in plasma, the organic group showed lower carbonyl and TBARS levels when compared to the conventional grape juice group (P < .05). Our findings suggest that the intake of purple grape juice, especially of organic juice, induces a better antioxidant capacity when compared to conventional juice and that this may be an important issue for further investigations in the area of biochemical functional foods.

Concord grape juice attenuates platelet aggregation, serum cholesterol and development of atheroma in hypercholesterolemic rabbits

Intake of Concord grape juice (CGJ), rich in polyphenolics, inhibits platelet aggregation (PA), a risk factor for cardiovascular disease (CVD), in normocholesterolemic animals and humans. It is unclear whether CGJ can attenuate hypercholesterolemia-enhanced PA. The effects of daily CGJ consumption on hypercholesterolemia-enhanced PA and the development of atherosclerosis were investigated. Two groups of rabbits (Control and Treated; n = 10 each) were fed a hypercholesterolemic diet for 48 days. Treated group then received supplemental CGJ (225 mL/day) while Control group received supplemental iso-caloric sugar water for 48 days. Collagen-, collagen + epinephrine- and phorbol-12-myristate-13-acetate-induced whole blood PA responses were measured on Days 0, 48 and 96; total serum cholesterol and blood pressure were also measured. The development of aortic atheroma was quantified at the end. Both groups showed significant increases in PA and serum cholesterol at Day 48. However, at Day 96, Treated group showed significantly lower PA and development of atheroma (30.7 ± 3.9% lower ( p < 0.001)) than Control group; Treated group also had significantly lower total serum cholesterol and blood pressure than Control group. In conclusion, daily consumption of CGJ attenuates hypercholesterolemia-enhanced PA, blood pressure, total serum cholesterol and development of atheroma in rabbits.

Purple grape juice inhibits 7,12-dimethylbenz[a]anthracene (DMBA)-induced rat mammary tumorigenesis and in vivo DMBA-DNA adduct formation

There has been considerable interest in identifying specific foods and phytochemicals that may have breast cancer preventive properties. Concord grapes are rich in polyphenolic chemicals and anthocyanin pigments that may have biological properties which could suppress cancer such as having antioxidant, antiproliferative, and proapoptotic actions. To determine the potential breast cancer protective action of purple grape juice, we examined the effect of grape juice consumption on the initiation stage of 7,12-dimethylbenz[a]anthracene (DMBA)-induced rat mammary tumorigenesis and on the in vivo formation of rat mammary DNA adducts in female Sprague–Dawley rats. Consumption of grape juice significantly inhibited mammary tumor mass at termination and the growth of tumors for the first 5 weeks of detectable tumor development. Consumption of grape juice phenolics by rats also significantly inhibited in vivo mammary DMBA-DNA adduct formation by 34 and 56% for animals fed phenolics at 346 and 692 mg/dL, respectively, compared to controls. Mammary 8-oxo-deoxyguanosine (8-oxo-dG) levels decreased by 25 and 37%, respectively, but the differences were not statistically significant. Liver DMBA-DNA adducts decreased by 10–30%, while 8-oxo-dG adducts remained unchanged, following grape juice intake. Liver glutathione S-transferase activity was significantly increased following grape juice consumption, but only at the highest level of intake. In addition, liver activities of catalase increased and xanthine oxidase decreased significantly, but only at the highest grape juice dose. Thus, these studies indicate that specific constituents or combinations of phytochemicals in purple grape juice can block the initiation stage of DMBA-induced rat mammary tumorigenesis. This tumor inhibitory effect was associated with a suppression of mammary DMBA-DNA adduct formation, which in part may be explained by increased liver activity of the phase II metabolizing enzyme, glutathione S-transferase. Mammary and liver 8-oxo-dG levels were not significantly altered by grape juice consumption. Thus, grape juice constituents appear to have benefit in decreasing susceptibility of the rat mammary gland to the tumor-initiating action of DMBA.

Children’s Growth Parameters Vary by Type of Fruit Juice Consumed

Background: Excessive fruit juice consumption in young children has been associated with nonorganic failure to thrive and short stature in some children and with obesity in others.Objective: To evaluate, in a sample of healthy young children, whether the associations between fruit juice intakes and growth parameters differ by the type of fruit juice consumed.Design: Cross-sectional study.Setting: General primary care health center in upstate New York.Participants: One hundred sixteen two-year-old children and one hundred seven five-year-old children, who were scheduled for a nonacute visit, and their primary care-takers or parents were recruited over a two-year period.Methods: For 163 children (73% of total), 14 days of dietary records were available. The dietary records were entered and analyzed using the Nutrition Data System (NDS). Type of fruit juice was classified according to Nutrition Coordinating Center food codes. Height was measured using a Harpenden Stadiometer. Weight was measured using a standard balance beam scale.Results: The children consumed, on average, 5.5 fluid oz/day of fruit juices, which were classified by the NDS software as 35% apple juice, 31% orange juice, 25% grape juice and 9% other types and/or mixtures of fruit juice. Children with higher fruit juice intakes had lower total fat, saturated fat and cholesterol intakes. Child height was inversely related to apple juice intake (p=0.007) and grape juice intake (p=0.02), after adjustment for child age, gender and energy intake (excluding fruit juice) and maternal height. Apple juice intake was correlated with child body mass index (p<0.05) and ponderal index (p<0.005), after adjustment for the above covariates. Total cholesterol, LDL-cholesterol, triglyceride and lipoprotein(a) levels were not related to intakes of any of the fruit juices examined. The children’s ratios of total cholesterol to HDL cholesterol were correlated with grape juice intakes, while HDL-cholesterol levels were inversely related to grape juice intakes. There were no significant relationships between fruit juice intake and measures of anemia (hematocrit or mean corpuscular volume).Conclusions: The previously reported associations between short stature and high intakes of fruit juice were observed for intakes of both apple juice and grape juice. The associations between high fruit juice intakes and obesity were observed with apple juice intakes only. Because most of the fruit juice mixtures were classified as single fruit juices, the findings, especially those with grape juice, need to be cautiously interpreted. High intakes of fruit juice, however, appear to be associated with growth extremes in young children. Thus, it would seem prudent for parents and caretakers to moderate the fruit juice intakes of their young children.