Indulging in a little dark chocolate might be good for your eyes, according to a recent study.
Researchers from Italy found that eating just a few squares of dark chocolate—around three from a standard bar—could improve how well the blood vessels in your eyes work. These vessels are essential for maintaining clear and healthy vision.
“The most surprising aspect was that a relatively small dose of dark chocolate is able to modify the motility and dilation of retinal vessels,” lead author Giuseppe Querques told The Epoch Times in an email.
Motility and dilation refer to the ability of blood vessels in the retina to move and expand.
Querques, who is also a professor of ophthalmology at the Università Vita-Salute San Raffaele in Milan, said that this suggests that dark chocolate might help prevent eye diseases and could have broader health benefits, as the effects seen in the eye’s blood vessels might reflect how cocoa affects the rest of the body.
“This opens an important scenario in the possible use of cocoa in the prevention of retinal diseases and potentially its systemic effects” in the rest of the body, Querques added.
Dark Chocolate Boosts Retinal Vessels
Published in
Nature, the study found that dark chocolate may improve blood circulation in the retinas.
It found that consuming dark chocolate significantly widened the blood vessels in the retina when exposed to flickering light. This widening improves blood flow, allowing the retina to receive more oxygen and nutrients, which helps it function properly.
The retina is responsible for turning light into signals that the brain interprets as images. Problems with the retina can lead to issues such as blurred vision, dark spots, or even loss of vision in certain areas.
Querques and the team compared the effects of dark chocolate with milk chocolate on retinal blood vessels. They tested 20 healthy adults, averaging 24 years old, who ate either 20 grams of dark or 7.5 grams of milk chocolate on separate days.
The dark chocolate contained 400 milligrams of flavanols—plants compounds known for their antioxidant and anti-inflammatory effects—while the milk chocolate contained fewer flavanols.
Two hours after eating the chocolate, the team found that dark chocolate led to a 4 percent expansion of the blood vessels, compared to a 2.75 percent expansion after eating milk chocolate. This represents a 45 percent greater increase.
The researchers attribute this positive effect to the flavanols in dark chocolate, suggesting that consuming dark chocolate might help improve the health and function of the blood vessels in the eyes.
According to Queques, dark chocolate helps increase the production of nitric oxide, which makes blood vessels in the eyes widen more. The plant compounds in dark chocolate boost the amount of nitric oxide in the body, leading to greater dilation of retinal vessels.
Building on Previous Studies
This finding adds to
earlier research from 2018, which showed that eating a bar of dark chocolate improved visual clarity and the ability to see differences between light and dark areas within a few hours. The researchers from that study proposed that this improvement might be due to increased blood flow to the retina, which helps deliver more oxygen and nutrients.
However, the new study didn’t find significant differences in overall blood flow or the structure of the retinal vessels between dark and milk chocolate. While dark chocolate seems to enhance the function of the blood vessels, it does not appear to affect their overall structure or blood flow, according to the study.
“Our study is only the first study demonstrating the effect of cocoa on retinal vessels,” Querques wrote, adding that further studies are needed to understand how regular dark chocolate consumption could impact the retinal blood vessels over time.
Diet and Retinal Health
Healthy retinal blood vessels are essential for clear vision and preventing serious eye conditions. According to the NIH’s National Eye Institute, damaged retinal blood vessels can lead to conditions such as diabetic retinopathy, caused by high blood sugar damage, and age-related macular degeneration, which affects vision.
In addition, the health of the retina is closely linked to overall cardiovascular health. Dark chocolate, rich in cocoa flavanols—found in cacao beans—has been found to offer some benefits. These flavanols, which make up between 50 to 90 percent of dark chocolate, improve blood flow and reduce inflammation. This means that maintaining a healthy heart can also positively affect your eyes.
Querques added that if further studies confirm that regular dark chocolate consumption plays a favorable role in preventing or managing retinal diseases, “daily cocoa intake could be used as a therapy or prevention not only of retinal but also of systemic diseases.”
