title: Concord grape juice, cognitive function, and driving performance: a 12-wk, placebo-controlled, randomized crossover trial in mothers of preteen children.
abstract: BACKGROUND
  Daily consumption of Concord grape juice (CGJ) over 3-4 mo has been shown to improve memory function in adults with mild cognitive impairment and reduce blood pressure in hypertensive adults. These benefits likely result from 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 with somewhat stressful and demanding lifestyles.
  
  
  OBJECTIVE
  We sought to examine the effects of the daily consumption of CGJ for 12 wk on cognitive function, driving performance, and blood pressure in healthy, middle-aged working mothers.
  
  
  METHODS
  Twenty-five healthy mothers (aged 40-50 y) of preteen children who were employed for ≥30 h/wk consumed 12 ounces (355 mL) of either CGJ (containing 777 mg total polyphenols) or an energy-, taste-, and appearance-matched placebo daily for 12 wk according to a randomized crossover design with a 4-wk washout. Verbal and spatial memory, executive function, attention, blood pressure, and mood were assessed at baseline and at 6 and 12 wk. Immediately after the cognitive battery, a subsample of 17 women completed a driving performance assessment at the University of Leeds Driving Simulator. The 25-min 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 after 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 the long-term 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 the cessation of flavonoid consumption, and future studies should carefully consider the length of washout within crossover designs. This trial was registered at clinicaltrials.gov as NCT01411631.
authors: School of Psychology and.
authors: Daniel J
authors: http://orcid.org/0000-0002-4592-0439
authors: DJ
authors: Lamport
authors: School of Psychology and.
authors: Clare L
authors: http://orcid.org/0000-0003-2341-0793
authors: CL
authors: Lawton
authors: Institute for Transport Studies, University of Leeds, Leeds, United Kingdom;
authors: Natasha
authors: http://orcid.org/0000-0003-4140-9948
authors: N
authors: Merat
authors: Institute for Transport Studies, University of Leeds, Leeds, United Kingdom;
authors: Hamish
authors: H
authors: Jamson
authors: School of Psychology and.
authors: Kyriaki
authors: K
authors: Myrissa
authors: School of Psychology and.
authors: Denise
authors: http://orcid.org/0000-0003-0994-3630
authors: D
authors: Hofman
authors: School of Psychology and.
authors: Helen K
authors: http://orcid.org/0000-0002-8022-5490
authors: HK
authors: Chadwick
authors: Quadt Consultancy BV, Schiedam, Netherlands; and.
authors: Frits
authors: F
authors: Quadt
authors: Welch Foods Inc., Concord, MA.
authors: JoLynne D
authors: http://orcid.org/0000-0002-3653-1714
authors: JD
authors: Wightman
authors: School of Psychology and l.dye@leeds.ac.uk.
authors: Louise
authors: http://orcid.org/0000-0002-2331-4227
authors: L
authors: Dye
mesh_terms: D000328:Adult; D001334:Automobile Driving; D001794:Blood Pressure; D003071:Cognition / Q000187:drug effects*; D018592:Cross-Over Studies; D004032:Diet; D005247:Feeding Behavior; D005260:Female; D005419:Flavonoids / Q000494:pharmacology; D005638:Fruit / Q000737:chemistry; D000067030:Fruit and Vegetable Juices; D006801:Humans; D008019:Life Style; D009035:Mothers / Q000523:psychology*; D028321:Plant Preparations / Q000494:pharmacology; D011597:Psychomotor Performance / Q000187:drug effects*; D065852:Spatial Memory / Q000187:drug effects; D013315:Stress, Psychological / Q000150:complications / Q000523:psychology; D027843:Vitis / Q000737:chemistry*; D014937:Work
chemical_list: D005419:Flavonoids; D028321:Plant Preparations
keywords: anthocyanins; cognition; cognitive function; driving; flavonoids; grape juice; memory; polyphenols