Purchase this article with an account.
Jeff C Rabin, Korey Patrizi, Nirmani Karunathilake; Acute Consumption of Dark Chocolate Improves Detection of Low Contrast Targets. Invest. Ophthalmol. Vis. Sci. 2018;59(9):1087.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Dark chocolate from favanol-rich cacao beans can retard memory loss and symptoms of senescent disease, improve cardiovascular function and enhance blood flow to central and peripheral nervous system. Our purpose was to determine if consumption of a commerically available, single dark chocolate bar improves visual acuity, large letter contrast sensitivity and/or small letter contrast sensitivity.
A single group of 30 healthy, visually normal, adult subjects (mean age ± SD = 26 years ± 5, 21 females, 9 males) participated in a randomized, masked crossover study to assess visual performance after acute consumption of a dark or a milk chocolate bar. High contrast visual acuity and small letter contrast sensitivity (20/25 letters) were measured binocularly with the retro-illuminated Precision Vision® Super Vision Test and large letter contrast sensitivity (20/700 letter size) measured with the wall mounted Pelli-Robson chart. LogMAR and logCS scoring were based on letters correct (0.02 logMAR, 0.05 logCS per letter). Each subject was tested 1.75 hours after dark (47g, 34g cacao, total flavanols: 316.3 mg) and milk chocolate bar consumption (40g, 12.4g milk chocolate cocoa; total flavanols: 40 mg) in separate sessions separated by at least 72 hours.
Overall performance improved after dark chocolate (F = 4.22, p < 0.05) with modest improvements in VA and large letter CS and a significant improvement in small letter contrast sensitivity (t = 4.91, p < 0.0005). Since 80% improved after dark chocolate (Wilcoxon signed-rank test, p < 0.00006), logMAR and logCS scores were added to form a composite spatial vision score for each subject encompassing contrast and spatial frequency. Bland-Altman analyses showed a significant improvement in composite score after acute consumption of dark chocolate (t = 4.18, p < 0.0003).
Acute consumption of a commercially available, highly palatable dark chocolate bar improves high and low contrast vision, likely due to flavanol-induced increases in retinal and/or cortical blood flow. Visual enhancement afforded by dark chocolate, particularly detection of small, low contrast targets, is important for everyday vision (e.g., driving) and critical task performance in law enforcement, military, and sports vision.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.
This PDF is available to Subscribers Only