A recent study published in the British Journal of Opthalmology indicates that drinking at least one cup of hot tea a day is linked to a significantly lower risk of developing glaucoma.
After taking into account potentially influential factors , such as diabetes and smoking, hot tea drinkers were 74 per cent less likely to have glaucoma.
Various forms of glaucoma cause fluid pressure to build up inside the eye ( intraocular pressure) damaging the optic nerve. It is one of the leading causes of blindness in the world and affects 400,000 Canadians.
Previous research has indicated that caffeine can alter intraocular pressure but no study had compared the potential impact of decaffeinated and caffeinated drinks and glaucoma risk. However, in this study interestingly drinking decaffeinated and decaffeinated coffee, decaffeinated tea, iced tea, and soft drinks didn’t seem to make any difference to glaucoma risk.
Teas do contain antioxidants and anti-inflammatory and neuroprotective chemicals which have been associated with a lowered risk of serious conditions including heart disease, cancer, and diabetes.
The study was an observational study of 1,678 participants in the US so no firm conclusions can be drawn about cause and effect. As well the absolute numbers of those with glaucoma in the study was small.
Glaucoma can be treated if detected early but the only way to detect it early is through regular comprehensive eye exams.
An abstract of the study can be found at: