Did Eating Dark Chocolate Improve Vision?

Apr 28, 2018
Did Eating Dark Chocolate Improve Vision?

Bottom Line: A small study found slight improvement in vision after eating dark chocolate.

Why The Research Is Interesting: Eating dark chocolate has been associated with better blood flow, mood and cognition in the short term but little is known about its possible effects on vision.

Who and When: 30 participants; testing was conducted from June to August 2017

What (Study Interventions and Outcomes): Eating a dark or milk chocolate bar (intervention); visual acuity and the ability to read letters of different sizes and contrast (lighter vs. darker letters) were measured about two hours after eating chocolate (outcomes)

How (Study Design): This was a randomized clinical trial (RCT). RCTs allow for the strongest inferences to be made about the true effect of an intervention such as a medication or a procedure. However, not all RCT results can be replicated in real-world settings because patient characteristics or other variables may differ from those that were studied in the RCT.

Authors: Jeff C. Rabin, O.D., M.S., Ph.D., University of the Incarnate Word Rosenberg School of Optometry, San Antonio, and coauthors


Meaning: Consumption of commercially-available dark chocolate bar improves the ability to see low-and high-contrast targets, possibly owing to increased blood flow, but the functional relevance of these slight improvements remains to be determined.

Study Limitations: How long the effect on vision might last is unknown.

Study Conclusions: Real-world effects on vision of eating chocolate need to be tested.

For more details and to read the full study, please visit the For The Media website.