Dipan Mondal, B.Optom

Fellow Optometrist, Dr shroff’s Charity Eye Hospital , New Delhi, India

What do you prefer Tea or Coffee? Which drink do you like to start the day with?

Let me know because you might want to put your focus on this. According to a study published in the British journal of ophthalmology , drinking a cup of hot tea once daily may reduce the risk of developing glaucoma in comparison with coffee, iced tea, and soft drinks.⁽¹⁾

Glaucoma is a group of diseases clinically characterized by damage of optic nerve mostly associated with raised ocular pressure.⁽²⁾ It is the leading cause of blindness worldwide and the world health organization ranks it as the most common cause of blindness worldwide after cataract. ⁽³⁾ In India, based on the available data, there are approximately 12.2 million people aged 40 years and older have been diagnosed with glaucoma. Primary open angle glaucoma affects nearly 6.48 million people and primary closer angle glaucoma affects 2.54 million people.

Tea contains various components such as Polyphenols, Caffeine, Amino acids, Vitamins, Flavonoids, Polysaccharides, and fluorine but tea’s most important health boosting chemicals called “Polyphenols”. Coffee also contains polyphenols, but they are different from the types found in tea. “We know that tea contains antioxidants and chemicals that help fight inflammation while protecting the brain”, said the lead study author Dr. Anne Coleman, a professor of ophthalmology at David Geffen school of medicine at the University of California, Los Angeles. ⁽¹⁾

According to study published in British Journal of Ophthalmology⁽¹⁾, researchers from Medical university of California, Los angles aimed to evaluate the association between consumption of coffee, tea or soft drinks and glaucoma. The result showed that who consumed at least one cup of tea daily had a 74% lower risk of having glaucoma compared with those who did not.⁽¹⁾ Since the study was observational, no firm associations could be drawn about the cause and effect. The study group was relatively small and the information on when glaucoma had been diagnosed was also unavailable. In this study, limited number of participants had glaucoma and research team was unaware of information. Also, the survey did not record details like cup size, tea type (i.e., black, white) and the amount of tea consumption per day, which could have been the influential factors .

The researchers found no links between glaucoma and consumption of hot tea. Thus, they concluded “Further research is needed to establish the importance of these findings and whether hot tea consumption may play a role in the prevention of glaucoma”. A previous study has reported tea to lower the risk of serious health condition including heart diseases, cancer, and diabetes⁽⁴⁾ whereas the prevention of glaucoma is still a mystery.

Reference:

1. Wu CM, Wu AM, Tseng VL, et al. Frequency of a diagnosis of glaucoma in individuals who consume coffee, tea and/or soft drinks .British Journal of Ophthalmology 2018;102:1127-1133.
2. George, Ronnie MS; Ve, Ramesh S. MPhil; Vijaya, Lingam MS Glaucoma in India: Estimated Burden of Disease, Journal of Glaucoma: August 2010 – Volume 19 – Issue 6 – p 391-397.
3. Resnikoff S, Pascolini D, Etya’ D, Kocur I, Pararajasegaram R, Pokharel GP, et al. Global data on visual impairment in the year 2002. Vol. 82, Bulletin of the World Health Organization. 2004.
4. Khan, N., & Mukhtar, H. (2013). Tea and health: studies in humans. Current pharmaceutical design, 19(34), 6141–6147.