A new study has suggested that heart-healthy compounds in dark chocolate might offer a slight and temporary improvement in vision quality.
The study, published April 26 in JAMA Opthalmology, involved a group of 30 healthy young adults, and found that flavanols appeared to sharpen eyesight. Although the observed change in vision was small, researchers called it significant. Even so, they noted that further testing is required before ophthalmologists begin to recommend chocolate as medicine for the eyes.
According to a team led by Dr. Jeff Rabin of the University of the Incarnate Word in San Antonio, Texas, “The duration of these effects and their influence in real-world performance await further testing.”
Web MD reported, “There’s been evidence in prior studies that the antioxidant flavanols in dark chocolate might help boost blood flow to the nervous system, boost heart function and even help preserve the aging brain. So, the investigators wondered if the eyes might reap some sort of benefit from chocolate, too.”
To answer that question, the researchers required 30 healthy adults, averaging 26 years of age, to eat either a 1.5-ounce Trader Joe’s 72 percent Cacao Dark Chocolate bar or a similar-sized Trader Joe’s Crispy Rice Milk Chocolate bar.
Approximately two hours later, each participant underwent vision testing using standard letter-based eye charts.
The researchers found “small enhancements in visual acuity and large-letter contrast” in those who had eaten the dark chocolate, compared to participants who had consumed milk chocolate.
Dr. Mark Fromer, an ophthalmologist at Lenox Hill Hospital in New York City, described visual acuity as a key component in the standard eye examination, where patients “specifically identify the letters on the eye chart.” Fromer, who was not involved in the study, noted that contrast sensitivity is “the ability to distinguish an object as the lighting is altered in intensity.”
Researchers stressed that the vision improvements experienced by the participants who ate dark chocolate “were small, and the [real life] functional relevance is unclear.”
According to Fromer, “The [study] authors suggest that this [improvement] may be a result of increased blood flow to the retina, visual pathways or [the brain’s] cerebral cortex, but there is currently no direct evidence to substantiate this claim.”
Fromer noted that it is too early for doctors to prescribe a dose of dark chocolate to help preserve good eyesight. “Further investigation will be necessary,” he said.