WASHINGTON (Dispatches) --- Consuming large amounts of daily caffeine may increase the risk of glaucoma more than three-fold for those with a genetic predisposition to higher eye pressure according to an international, multi-center study.
The research led by the Icahn School of Medicine at Mount Sinai is the first to demonstrate a dietary -- genetic interaction in glaucoma. It looks at the impact of caffeine intake on glaucoma, and intraocular pressure (IOP) which is pressure inside the eye. Elevated IOP is an integral risk factor for glaucoma, although other factors do contribute to this condition. With glaucoma, patients typically experience few or no symptoms until the disease progresses and they have vision loss.
The investigators found high caffeine intake was not associated with increased risk for higher IOP or glaucoma overall; however, among participants with the strongest genetic predisposition to elevated IOP -- in the top 25 percentile -- greater caffeine consumption was associated with higher IOP and higher glaucoma prevalence. More specifically, those who consumed the highest amount of daily caffeine- more than 480 milligrams which is roughly four cups of coffee -- had a 0.35 mmHg higher IOP. Additionally, those in the highest genetic risk score category who consumed more than 321 milligrams of daily caffeine -- roughly three cups of coffee -- had a 3.9-fold higher glaucoma prevalence when compared to those who drink no or minimal caffeine and in lowest genetic risk score group.