A study has found that daily high caffeine consumption may increase the risk of glaucoma more than three-fold in people who are genetically predisposed to developing the disease. 

Results of the international study, led by the Icahn School of Medicine at Mount Sinai and published in the June issue of Ophthalmology, are the first to illustrate that an interaction between diet and genetics could be integral to the development of glaucoma, the leading cause of blindness in the United States.

What They Did

The research team analyzed the health records and DNA samples of more than 120,000 people between 39 and 73 years old. Over the course of the four-year study, participants also filled out periodic questionnaires concerning:

• How many caffeinated beverages they drank daily 
• How much caffeine-containing food they ate, including types and portion sizes 
• Their vision, current glaucoma, and family history of glaucoma 

In year three of the study, participants’ eye measurements were taken and their intraocular pressure (IOP) was checked. The team evaluated the relationship(s) between:

• Caffeine intake
• IOP
• Self-reported glaucoma

What They Found

The data revealed that:

• High caffeine intake was not linked to higher risk for either elevated IOP or glaucoma overall. 
• High caffeine intake was associated with both elevated IOP and glaucoma in participants with the strongest genetic predisposition for elevated IOP (top 25th percentile).
• Those who consumed more than 480 mg of caffeine daily (approximately four cups of coffee) had higher IOP.  
• Those in the highest genetic risk score category who consumed more than 321 mg of caffeine daily (approximately three cups of coffee) had a 3.9-fold higher glaucoma prevalence than those who consumed little caffeine and had low genetic risk. 

What it Means

The findings indicate that people with a family history of either glaucoma or elevated IOP may benefit from keeping their caffeine intake to a minimum. “We previously published work suggesting that high caffeine intake increased the risk of the high-tension open angle glaucoma among people with a family history of disease,” added lead author Louis R. Pasquale, MD, Deputy Chair for Ophthalmology Research for the Mount Sinai Health System. 

“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.” 

*Mount Sinai. (2021, June 7). High Caffeine Consumption may be Associated with Increased Risk of Blinding Eye Disease [Press Release]. https://www.mountsinai.org/about/newsroom/2021/high-caffeine-consumption-may-be-associated-with-increased-risk-of-blinding-eye-disease