Latest Research Shows Dark Chocolate May Improve Eyesight


Much to the delight of choco-holics everywhere, researchers continue to investigate the potential health benefits of the tasty elixir of the cocoa bean. The health benefits of chocolate are thought to originate with flavanols – potent antioxidant compounds – found naturally in significant concentrations in the cocoa bean. The latest research, published in the current issue of JAMA Ophthalmology, compared the impact on visual acuity and contrast sensitivity of both milk chocolate and dark chocolate.


But – if you like chocolate as much as we like chocolate – you’ll want specifics:


  • Dark chocolate was represented by a 47 g 72% Cacao Dark Chocolate bar (containing 34 g of cacao with a total flavanols amount of 316.3 mg)

  • Milk chocolate was represented by a 40 g Crispy Rice Milk Chocolate bar (containing 12.4 g of milk chocolate cocoa with a total flavanols amount of 40 mg [8 times less than dark chocolate bar])


Thirty fortunate adults participated in the study that required them to eat chocolate and then have their vision checked within 2 hours. Dark chocolate contains higher amounts of the flavanol compounds and the study showed dark chocolate conferred more benefits than milk chocolate. Specifically, those who ate dark chocolate before having their vision evaluated:


  • Had significantly higher small-letter contrast sensitivity than those who consumed the milk chocolate bar

  • Had higher large-letter contrast sensitivity measurements, but not significantly more than the milk chocolate cohort

  • Had slight improvement in high-contrast visual acuity and standard visual acuity over those who had milk chocolate


There may be a common pathway between the visual perception improvements and the cardiovascular protective effect, namely the effect of plant molecules called polyphenols. The polyphenols found in cocoa are called flavanols. These have a positive effect on our blood vessels, by healing damage to the lining, relaxing the muscle and improving blood flow. Studies show that cocoa flavanols also improve blood sugar metabolism and reduce the risk of developing diabetes, as well as reduce risk for heart and vascular disease in patients who have diabetes.


The authors of the visual study hypothesize that cocoa flavanols enhance availability of oxygen and nutrients to the blood vessels of the eye and brain. The retina in particular, they point out, is very highly vascularized and may be the area of interest in these study findings.


This post originally appeared on American Refractive Surgery Council.