A daily cup of hot tea may help protect against glaucoma—a leading cause of blindness—according to a study published in the British Journal of Ophthalmology. The study looked at information gathered from about 10,000 participants in the 2005–2006 National Health and Nutrition Examination Survey. In the annual survey, participants answered questions about dietary habits, including how often they drank caffeinated and decaf coffee, hot and iced tea, and soft drinks over the past 12 months. They also underwent blood tests and physical examinations. Researchers found that complete eye exam results were available for 1,678 participants, and within this subgroup, 5.1% had developed glaucoma. After analyzing all the data from this subgroup and adjusting for the effects of smoking habits, diabetes, and other factors that could alter glaucoma risk, they noted that:
Drinking at least one cup of caffeinated hot tea daily was associated with a 74% lower likelihood of developing glaucoma compared with drinking less or none.
Drinking decaf hot tea, caffeinated or decaf coffee, iced tea, and soft drinks did not affect glaucoma risk.
As you toast to your eye health with a cuppa, just remember that, while this study observed a correlation, its findings do not establish a cause and effect relationship between drinking hot tea and glaucoma. The study also didn’t include potentially significant details such as type of tea, cup size, or brewing time. But if you love tea, drink up! Tea is brimming with antioxidants and has been associated with a host of other health benefits, including boosted immunity, heart health, and a reduced risk of some cancers in women.
Source: British Journal of Ophthalmology