Good news for chocolate lovers.
Eating a lot of chocolate may have some drawbacks in terms of calorie intake, but positive effects on blood pressure, mood and cognitive ability have long been known in the short term. Little was known, however, about the effects of chocolate intake on visual performance.
The good news comes from a study published in April 2018 in JAMA Ophthalmology, in which Dr Jeff Rabin and his team of researchers from the 'Rosenberg School of Optometry' in San Antonio, Texas (USA), compared the effects on visual acuity and contrast sensitivity of consuming dark chocolate versus milk chocolate.
The cross-sectional, randomised clinical trial involved 30 adults with no previous eye disease and focused on short-term effects: two hours after intake.
The overall result was that, after two hours, the intake of a bar of dark chocolate resulted in slight improvements in visual acuity compared to the intake of the same amount of milk chocolate: in detail: 0.22 logMAR, approx. 20/12, in the group that had eaten dark chocolate vs. 0.18 logMAR, approx. 20/15, in the group that had eaten milk chocolate.
There was also a greater increase in contrast sensitivity with dark chocolate. Interestingly, the effect was more pronounced for contrast sensitivity for small characters, while it was less pronounced in the case of large characters.
Further studies will be needed for the long-term effects on both visual parameters.
References
Rabin JC, et al. Effects of Milk vs Dark Chocolate Consumption on Visual Acuity and Contrast Sensitivity Within 2 Hours. A Randomized Clinical Trial. JAMA Ophthalmol. 2018; doi:10.1001/jamaophthalmol.2018.0978.
Dr. Carmelo Chines
Direttore responsabile
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