The commercially available dark chocolate bar can improve high and low-contrast vision within 2 hours after consumption, according to a study published in JAMA
Jeff C. Rabin, OD, MS, Ph.D., University of the Incarnate Word Rosenberg School of Optometry, and his associates conducted a study to compare the short-term effects of consumption of dark chocolate with those of milk chocolate on visual acuity and large and small-letter contrast sensitivity.
The earlier study reveals that consumption of dark chocolate can improve blood flow, mood, and cognition in the short term, but little is known about the possible effects of dark chocolate on visual performance.
Thirty adults with no history of ocular, systemic, or neurologic disease were included in the study and were randomly assigned to the group that began testing after dark chocolate consumption or the group that began testing after milk chocolate consumption.Testing was conducted at the Rosenberg School of Optometry from June 25 to August 15, 2017
All participants underwent binocular testing with high contrast visual acuity and small-letter contrast sensitivity.
Among the 30 participants (9 men and 21 women; mean [SD] age, 26  years), small-letter contrast sensitivity was significantly higher after consumption of dark chocolate (mean [SE], 1.45 [0.04] logCS) vs milk chocolate (mean [SE], 1.30 [0.05] logCS; mean improvement, 0.15 logCS [95% CI, 0.08-0.22 logCS]; P < .001). Large-letter contrast sensitivity was slightly higher after consumption of dark chocolate (mean [SE], 2.05 [0.02] logCS) vs milk chocolate (mean [SE], 2.00 [0.02] logCS; mean improvement, 0.05 logCS [95% CI, 0.00-0.10 logCS]; P = .07). Visual acuity improved slightly after consumption of dark chocolate (mean [SE], −0.22 [0.01] logMAR; visual acuity, approximately 20/12) and milk chocolate (mean [SE], −0.18 [0.01] logMAR; visual acuity, approximately 20/15; mean improvement, 0.04 logMAR [95% CI, 0.02-0.06 logMAR]; P = .05). Composite scores combining results from all tests showed significant improvement after consumption of dark compared with milk chocolate (mean improvement, 0.20 log U [95% CI, 0.10-0.30 log U]; P < .001).
The study reports that a single dose of dark chocolate improves the visibility of small, low-contrast targets within 2 hours compared with milk chocolate, but the duration of this difference and clinical relevance remains uncertain.
The study was published in the journal JAMA
For more reference log on to: http://10.1001/jamaophthalmol.2018.0978