In the United Kingdom, drinking a cup of hot tea at least once a day may be linked to a significantly lower risk of developing glaucoma, but drinking decaffeinated and caffeinated coffee, decaffeinated tea, iced tea and soft drinks doesn’t make any difference to glaucoma risk.
One of the leading causes of blindness worldwide, glaucoma causes fluid pressure to build up inside the eye, damaging the optic nerve. It currently affects 57.5 million people and could affect as many as 65.5 million by 2020.
Previous research suggests that caffeine can alter intraocular pressure, but no study so far has compared the potential impact of decaffeinated and caffeinated drinks on glaucoma risk. So the researchers looked at data from the 2005-2006 National Health and Nutrition Examination Survey in the US. Compared with those who didn’t drink hot tea every day, those who did, had a lower glaucoma risk, the data showed.