“We previously published work suggesting that high caffeine intake increased the risk of high-tension open angle glaucoma among people with a family history of disease,” said Dr. Louis R. Pasquale. “In this study we show that an adverse relation between high caffeine intake and glaucoma was evident only among those with the highest genetic risk score for elevated eye pressure.”
The link between caffeine and eye health
The researchers analyzed data from more than 120,000 participants enrolled in the U.K. Biobank. Participants were between the ages of 39 and 73, and they all completed questionnaires about their vision histories and overall diets, including their caffeine intake. The researchers also analyzed DNA samples to understand their genetic likelihood of developing glaucoma and administered vision exams three years into the study.
The study showed that high caffeine consumption was most harmful to the participants’ vision when they were genetically predisposed to glaucoma. The researchers found that a family history of glaucoma was associated with higher intraocular pressure (IOP). IOP scores were lower among those with no genetic association to the eye disease, and high caffeine consumption wasn’t associated with vision changes.
Those who drank four cups of coffee per day -- or the caffeine equivalent -- and had a family history of glaucoma were at the highest risk of developing glaucoma themselves. Drinking three cups of coffee per day increased the risk of glaucoma by nearly four times for those with the highest IOP levels and family ties to the disease.
The researchers hope that these findings can be helpful to those with a genetic predisposition to glaucoma. They believe these consumers can have better long-term vision health by reducing caffeine consumption.
“Glaucoma patients often ask if they can help protect their sight through lifestyle changes, however this has been a relatively understudied area until now,” said researcher Dr. Anthony Khawaja. “This study suggested that those with the highest genetic risk for glaucoma may benefit from moderating their caffeine intake."