BOSTON, Oct. 5 (UPI) -- Heavy consumption of caffeinated coffee -- three cups or more daily -- is associated with an increased risk of developing glaucoma, U.S. researchers say.
Study author Jae Hee Kang of Channing Division of Network Medicine at Brigham and Women's Hospital in Boston said the study involved 78,977 women from the Nurses' Health Study and 41,202 men from the Health Professionals Follow-up Study. Study participants were at least 40 years of age, did not have glaucoma and reported undergoing eye examinations from 1980 on for the nurses and from 1986 for the health professionals to 2008.
Researchers questioned study participants about the beverages they drank and reviewed medical records to determine cases of exfoliation glaucoma, or glaucoma suspect, which contributes to elevated pressure sufficient to damage the optic nerve, causing glaucoma. Patients with exfoliation glaucoma are believed to have optic nerve damage, but not enough for a diagnosis, Kang said.
A meta-analysis of the two groups showed participants who drank three cups or more of caffeinated coffee daily were at an increased risk of developing exfoliation glaucoma, compared to abstainers of coffee.
"Because this is the first study to evaluate the association between caffeinated coffee and exfoliation glaucoma in a U.S. population, confirmation of these results in other populations would be needed to lend more credence to the possibility that caffeinated coffee might be a modifiable risk factor for glaucoma," said Kang.