title: Blueberry effects on dark vision and recovery after photobleaching: placebo-controlled crossover studies.
abstract: Clinical evidence for anthocyanin benefits in night vision is controversial. This paper presents two human trials investigating blueberry anthocyanin effects on dark adaptation, functional night vision, and vision recovery after retinal photobleaching. One trial, S2 (n = 72), employed a 3 week intervention and a 3 week washout, two anthocyanin doses (271 and 7.11 mg cyanidin 3-glucoside equivalents (C3g eq)), and placebo. The other trial, L1 (n = 59), employed a 12 week intervention and an 8 week washout and tested one dose (346 mg C3g eq) and placebo. In both S2 and L1 neither dark adaptation nor night vision was improved by anthocyanin intake. However, in both trials anthocyanin consumption hastened the recovery of visual acuity after photobleaching. In S2 both anthocyanin doses were effective (P = 0.014), and in L1 recovery was improved at 8 weeks (P = 0.027) and 12 weeks (P = 0.030). Although photobleaching recovery was hastened by anthocyanins, it is not known whether this improvement would have an impact on everyday vision.
authors.affiliation: Agriculture and Agri-Food Canada, Atlantic Food and Horticulture Research Centre, 32 Main Street, Kentville, Nova Scotia B4N 1J5, Canada.
authors.forename: Wilhelmina
authors.initials: W
authors.lastname: Kalt
authors.forename: Jane E
authors.initials: JE
authors.lastname: McDonald
authors.forename: Sherry A E
authors.initials: SA
authors.lastname: Fillmore
authors.forename: Francois
authors.initials: F
authors.lastname: Tremblay
mesh_terms: D000328:Adult; D000368:Aged; D029798:Blueberry Plants / Q000378:metabolism*; D018592:Cross-Over Studies; D003623:Dark Adaptation; D005260:Female; D005638:Fruit / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D038761:Photobleaching; D011446:Prospective Studies; D012160:Retina / Q000502:physiology* / Q000528:radiation effects; D014785:Vision, Ocular
keywords: anthocyanin; blueberry; clinical; night vision; retina