Concord grape Juice, cognitive function and driving performance: a 12 week, placebo controlled, randomised, crossover trial in mothers of pre-teen children

Background: Daily consumption of Concord grape juice (CGJ) over three to four months has been shown to improve memory function in adults with mild cognitive impairment, and reduce blood pressure in hypertensive adults. These benefits are likely due to the high concentration of polyphenols in CGJ. Increased stress can impair cognitive function and elevate blood pressure. Thus we examined the potential beneficial effect of CGJ in individuals experiencing somewhat stressful demanding lifestyles. Objective: To examine the effects of twelve weeks’ daily consumption of CGJ on cognitive function, driving performance, and blood pressure in healthy, middle-aged working mothers. Design: Twenty five healthy mothers of pre-teen children, aged 40-50 years, who were employed for > 30 hours/week consumed 12oz (355ml) CGJ (containing 777mg total polyphenols) or an energy, taste and appearance matched placebo daily for twelve weeks according to a randomised, crossover design with a four week washout. Verbal and spatial memory, executive function, attention, blood pressure and mood were assessed at baseline, six weeks and twelve weeks. Immediately following the cognitive battery, a subsample of seventeen females completed a driving performance assessment in the University of Leeds Driving Simulator. The twenty five minute driving task required participants to match the speed and direction of a lead vehicle. Results: Significant improvements in immediate spatial memory and driving performance were observed following CGJ relative to placebo. There was evidence of an enduring effect of CGJ such that participants who received CGJ in arm 1 maintained better performance in the placebo arm. Conclusions: Cognitive benefits associated with chronic consumption of flavonoid-rich grape juice are not exclusive to adults with mild cognitive impairment. Moreover, these cognitive benefits are apparent in complex everyday tasks such as driving. Effects may persist beyond cessation of flavonoid consumption and future studies should carefully consider the length of washout within crossover designs

Comparative assessment of phenolic bioaccessibility from 100% grape juice and whole grapes

Concord and Niagara grape juice have comparable or greater absolute bioaccessibility of major classes of phenolic compounds compared to masticated whole grapes.</p

The effects of flavonoid and other polyphenol consumption on cognitive performance: A systematic research review of human experimental and epidemiological studies

Literature reviews suggest flavonoids, a sub-class of polyphenols, are beneficial for cognition. This is the first review examining the effect of consumption of all polyphenol groups on cognitive function. Inclusion criteria were polyphenol vs. control interventions and epidemiological studies with an objective measure of cognitive function. Participants were healthy or mildly cognitively impaired adults. Studies were excluded if clinical assessment or diagnosis of Alzheimer’s disease, dementia, or cognitive impairment was the sole measure of cognitive function, or if the polyphenol was present with potentially confounding compounds such as caffeine (e.g. tea studies) or Ginkgo Biloba. 28 studies were identified; 4 berry juice studies, 4 cocoa studies, 13 isoflavone supplement studies, 3 other supplement studies, and 4 epidemiological surveys. Overall, 16 studies reported cognitive benefits following polyphenol consumption. Evidence suggests that consuming additional polyphenols in the diet can lead to cognitive benefits, however, the observed effects were small. Declarative memory and particularly spatial memory appear most sensitive to polyphenol consumption and effects may differ depending on polyphenol source. Polyphenol berry fruit juice consumption was most beneficial for immediate verbal memory, whereas isoflavone based interventions were associated with significant improvements for delayed spatial memory and executive function. Comparison between studies was hampered by methodological inconsistencies. Hence, there was no clear evidence for an association between cognitive outcomes and polyphenol dose response, duration of intervention, or population studied. In conclusion, however, the findings do imply that polyphenol consumption has potential to benefit cognition both acutely and chronically

Consumption of Purple/Blue Produce Is Associated With Increased Nutrient Intake and Reduced Risk for Metabolic Syndrome: Results From the National Health and Nutrition Examination Survey 1999-2002

To determine the effect of consuming purple/blue fruit and vegetables (P/B) on nutrient intakes and physiological parameters, a secondary analysis of National Health and Nutrition Examination Survey (NHANES) 1999-2002 data for children aged 5 to 18 years (n = 6345) and adults 19+ years (n = 8827) was conducted. Compared with nonconsumers (n = 13 304), P/B consumers (n = 1559) had increased intakes of total fruit (P &lt; .0001), dietary fiber (P ≤ .0001), vitamin C (P &lt; .001), and potassium (P &lt; .0001) and decreased intakes of added sugar (P &lt; .0001). P/B consumers had higher energy intakes (P &lt; .001), but among children, there were no differences in weight or body mass index (BMI) for age between groups; among adults, lower weight and BMI (P &lt; .0001) were found as compared with nonconsumers. Adult P/B consumers had significantly reduced risk for 3 of the 5 risk factors that define the metabolic syndrome (MetS): elevated blood pressure, low HDL cholesterol, and increased waist circumference. An additional analysis for the subgroup of 100% grape juice (GJ) consumers was conducted. GJ consumers (n = 270) also had higher intakes of fruit (P &lt; .001), vitamin C (P &lt; .001), and potassium (P &lt; .005) and lower intakes of added sugar (P &lt; .01) compared with GJ nonconsumers (n = 14 902), with no differences in weight, BMI, or waist circumference. Consumption of P/B produce was associated with increased fruit and nutrient intakes and with reduced risk for MetS. GJ consumption was also associated with increased nutrient intake.</jats:p

Effects of Concord grape juice flavor intensity and phenolic compound content on glycemia, appetite and cognitive function in adults with excess body weight: a randomized double-blind crossover trial

Concord grape juice phenolics and flavor intensity moderate appetite and glycemia in adults with excess body weight, depending on the dietary context in which the juice is consumed.</jats:p