Caffeine increases POAG risk

High caffeine intake is associated with an increased risk of high-tension primary open angle glaucoma (POAG) in subjects with a positive family history of glaucoma, according to a study published in the May 2008 issue of Investigative Ophthalmology & Visual Science.

Jae Hee Kang, ScD of Harvard Medical School, US and colleagues observed subjects aged ≥40 years without POAG to determine if caffeine, which raises intraocular pressure (IOP), is also associated with an increased risk of POAG.

Of the 121,172 subjects monitored and followed-up with questionnaires between 1980 and 2004, 1011 POAG cases were confirmed. The researchers found that higher levels of caffeinated coffee intake correlated with increased risk of POAG, particularly POAG with elevated IOP, in those with a family history of glaucoma.

Compared with an intake of ≤150 mg/day, consumption of 150–299 mg/d was associated with a 1.05 increased risk; for 300–449 mg/d, risk increased 1.19 times; consuming 450–599 mg/d carried a 1.13 greater risk; for ≥600 mg/d, risk increased 1.17 times. Where ≥5 cups of caffeinated coffee were consumed daily, the risk was 1.61 times greater. Consumption of tea and caffeinated cola did not correlate with an increased risk.

Greater caffeine intake was associated with elevated POAG risk only in those with positive family histories of glaucoma. The researchers concluded that these results warrant further study, as the apparent increased risk may be an accident of chance rather than a concrete correlation.