October 4, 2012
For All Its Goodness, New Report Says Coffee Can Cause Blindness
Michael Harper for redOrbit.com — Your Universe Online
Like any addictive substance, coffee has a knack of drawing a distinct line in the sand between those in favor of the beverage and those who whine and complain during every family holiday when someone begins to brew a pot.
Medical science also seems evenly split on the effects of coffee, with some reports calling it a detriment and others calling it delight. For instance, a May report in the New England Journal of Medicine claims those who drink 2 or 3 cups of joe a day have a better chance at outliving their anti-coffee peers.
However, according to a new paper published in Investigative Ophthalmology & Visual Science, coffee drinkers could have an increased risk of developing exfoliation glaucoma. So, heavy coffee drinkers might very well live longer, but they might also spend the last years of their lives blind.
This study, entitled: “The Relation between Caffeine and Coffee Consumption and Exfoliation Glaucoma or Glaucoma Suspect: A Prospective Study in Two Cohorts," is the first of its kind to draw a link between caffeinated coffee and exfoliation glaucoma in American coffee fans. According to the study´s author, Jae Hee Kang, the high levels of this coffee consumption in other countries spurred their desire to study these effects on Americans.
“Scandinavian populations have the highest frequencies of exfoliation syndrome and glaucoma,” said Kang, ScD, of Channing Division of Network Medicine at Brigham and Women´s Hospital in Boston, Mass.
“Because Scandinavian populations also have the highest consumption of caffeinated coffee in the world, and our research group has previously found that greater caffeinated coffee intake was associated with increased risk of primary open-angle glaucoma, we conducted this study to evaluate whether the risk of exfoliation glaucoma or glaucoma suspect may be different by coffee consumption.”
Kang and team had to cull together 2 different data sets in order to conduct their research; Data from nearly 79,000 women from the Nurses´ Health Study (NHS) and data from just over 41,000 men from the Health Professionals Follow-up Study (HPFS). Each of these participants were at least 40 years old, without glaucoma and had reported going to regular eye exams from either 1980 or 1986 to 2008, depending on the data set used. Kang and team then crafted a questionnaire to determine how much coffee and other caffeinated beverages these participants consumed in a day, balancing this data with the reviewed medical records to determine cases of exfoliation of glaucoma. This type of glaucoma raises the pressure on the optic nerve, damaging it.
After extrapolating the data, the researchers found that the same coffee drinkers who enjoy 3 or more cups of the fully loaded stuff a day have an increased risk of exfoliation glaucoma or glaucoma suspect. This risk only seems to accompany coffee drinking, however, as the researchers were not able to find the same link to other caffeinated beverages, such as soda or tea. Women with a family history or glaucoma were also at an increased risk when they enjoyed a few cups of coffee a day.
“Because this is the first study to evaluate the association between caffeinated coffee and exfoliation glaucoma in a US 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 in the press statement.
“It may also lead to research into other dietary or lifestyle factors as risk factors.”