Drinking hot tea linked to lower risk of glaucoma

A new study released in the British Journal of Ophthalmology is showing a strong link between drinking hot tea with a lower risk of glaucoma.  The researchers found that those who drank daily caffeinated hot tea were 74 percent less likely to be diagnosed with glaucoma compared to those who drank no tea. 

What is glaucoma?

Glaucoma is a condition resulting in progressive damage to the optic nerve due to high pressure in the eye (intraocular pressure).  Normally we have a clear fluid flowing in and out of the space in front of the eye that brings nutrients to nearby tissue.  Glaucoma causes this fluid to pass too slowly or stops it altogether.  When this occurs, fluid builds up causing pressure inside the eye damaging the optic nerve with possible vision loss.

In time, glaucoma can lead to loss of peripheral or side vision and eventually total loss of vision or blindness.  In the United States, glaucoma affects around 3 million Americans and it is the leading cause of blindness.   It is considered the second leading cause of blindness worldwide affecting up to 2% of the population.

Results from study

For the study, researchers from UCLA analyzed health and diet questionnaires from 1,678 men and women who participated in the National Health and Nutrition Examination Survey.  The purpose was to evaluate the association between consumption of coffee, tea, or soft drinks and glaucoma among the study participants.  Results showed a connection between those who daily drank at least one cup of hot tea had lower odds of developing glaucoma than those who drank little to no hot tea.  The findings also showed no statistically significant association that existed for decaffeinated hot tea. 

It should be noted that the study did not differentiate between what type of tea the study participants were drinking (i.e., black, green, white), or the amount of tea consumed daily.  All that it did state was that at least one cup or 8 ounces a day had a connection with lowering glaucoma. 

Past research has already shown a link between consuming hot tea with lowered risks of heart disease and possibly cancer.  With this new finding, it adds to the growing list of improved health benefits hot tea has to offer.

In regards to whether coffee drinkers had the same advantage as tea drinkers in lowering their risk of developing glaucoma, this recent study showed no links observed between coffee consumption and glaucoma – this was also true for iced tea, decaffeinated tea, and any kind of soda. 

Researchers with the study pointed out that even though the study shows an association between tea drinking and a lower risk of glaucoma, it does not prove that drinking hot tea will necessarily prevent the condition. They stated that you have to look at the entire picture of what other lifestyle habits hot tea drinkers do that could also be contributing to reducing their risk of glaucoma. 

One thing known for sure is that tea contains polyphenols which are antioxidants that help protect against and repair cell damage.  It is these polyphenols that are believed to contribute to the other health benefits associated with tea. 

Polyphenols are also found in coffee but are not the same as those found in tea.  This could be the reason why coffee did not offer the same benefits on glaucoma as apparently tea does.