Improved mood and sustained attention following acute consumption of Concord grape juice in young, healthy adults: a randomised, placebo-controlled, double-blind, cross-over study

Abstract

Berry-derived polyphenols found in purple grape juice have been associated with a number of health benefits in humans, including better episodic memory (1) and improved endothelial function (see 2 for review) . Previous intervention studies of Concord grape juice have demonstrated improvement to memory in age-associated mild cognitive impairment following at least 12 weeks supplementation, as well as increased brain activation (assessed with fMRI) following 16 weeks intervention. Anthocyanin-rich berry extracts have also been observed to improve sustained attention when measured acutely in healthy young adults (3) but no studies to date have demonstrated acute cognitive effects of grape juice. This randomised, placebo-controlled, double-blind, balanced-crossover study, assessed the effects of a single dose of 200 ml Concord purple grape juice or sugar and flavour-matched placebo in 20 healthy young adults. Computerised measures of cognition and mood were completed at baseline and following a 20-min absorption period, chosen due to a peak in native anthocyanins at 30 minutes post-ingestion. Speed of Attention Placebo Grape -40 -20 0 20 40 60 80 100 Calm Placebo Grape -15 -10 -5 0 5 10 15 msecs x3 mm Change from baseline Following a single serve of Concord purple grape juice, a significant increase in calm ratings (p < 0.05) and an improvement in speed of attention (p < 0.05) were observed. There were no effects on memory. This supports a previous demonstration of improved sustained attention following berry fruit, possibly implicating this as an anthocyanin effect, which account for 46 % of the polyphenolic content of the grape juice administered. However, the phenolic acids, flavanols and flavonols also present are liable to play a role in any neuro-cognitive effect. These findings in a small sample of healthy young adults suggest that further investigation of the efficacy of purple grape juice in preventing age-associated cognitive decline is warranted to ascertain peak dose effects as well as exploring the active com-pound(s) responsible for such effects. A double blind placebo controlled study measuring the effect of two berry fruit extracts on mood, cognition and monoamine oxidase B inhibition in healthy young adults. Appetite 59, 636.