- Drinking a cup of hot tea everyday can lower the risk of glaucoma
- No link was found between glaucoma and caffeinated or decaffeinated coffee or decaffeinated tea, iced tea or soft drinks
- Oxidation and neurodegeneration could be involved in the development of glaucoma
Drinking a cup of hot tea once a day can lower the risk of developing glaucoma. However, drinking caffeinated or decaffeinated coffee, iced or decaffeinated tea, and soft drinks did not reduce the glaucoma risk, reveals a new study.
The study was published online in the British Journal of Ophthalmology.
‘Antioxidants and anti-inflammatory and neuroprotective chemicals present in tea help in lowering the risk of severe conditions like heart disease, diabetes, and cancer.’
a severe eye condition causes fluid pressure to build up inside the eye, which damages the optic nerve.
Glaucoma, one of the leading causes of blindness affects about 57.5 million people currently and is expected to increase by 2020 to 65.5 million.
Previous studies revealed that caffeine could alter intraocular pressure. However, there are no studies that compare the potential effects of decaffeinated and caffeinated drinks on the risk of glaucoma.
Impact of Decaffeinated and Caffeinated Drinks on the Risk of Glaucoma
The research team investigated data collected from the 2005-2006 National Health and Nutrition Examination Survey (NHANES), U.S.
The data collected is a nationally representative annual survey including about 10,000 people and their interviews, physical examinations and blood samples. All these were obtained from the US adults and children to track their health and nutritional status.
During this year, the research team has also included eye tests to check the presence of glaucoma. Out of 1678 participants who had a full eye test, including photos, about 84 participants (5%) were found to develop the condition.
The participants were given a validated questionnaire (Food Frequency) to know about their consumption of caffeinated and decaffeinated drinks, including soft drinks and iced tea in the preceding 12 months.
Findings of this Study
The results obtained were compared, and they found that those who had tea on a daily basis had lower glaucoma risk than those who didn't drink hot tea.
The research team had also taken other influential factors into account like diabetes and smoking. They found that hot tea-drinkers were 74 percent less likely to develop glaucoma. However, there was no link found for caffeinated or decaffeinated coffee and decaffeinated tea, iced tea or soft drinks.
This is an observational study. Therefore, no definite conclusions were made of their cause and effect, as the absolute numbers of the participants who developed glaucoma were small.
The research team was unaware of the information as to when glaucoma was diagnosed. The questionnaire did not have factors such cup size, tea type, or the length of brewing time, which could have been the influential factors.
Tea contains antioxidants and anti-inflammatory and neuroprotective chemicals that aids in reducing the risk of severe conditions like heart disease, diabetes, and cancer,
reveals the research team.
Previous studies have revealed that oxidation and neurodegeneration could be involved in the development of glaucoma.
The research team 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."
What is Glaucoma?
A glaucoma is a group of disorders involving the optic nerve, often associated with a rise in intraocular pressure. Uncontrolled glaucoma can lead to blindness.
This optic nerve and visual field changes occur when there is a sustained rise in intraocular pressure. A sudden surge which is regulated very soon does not give rise to these changes unless repeated episodes occur.
Primary open angle glaucoma is more common and accounts for almost three-quarters of glaucoma cases.
Treatment of glaucoma depends upon the type and stage of glaucoma. It is important to realize that treatment does not reverse the damage to the optic nerve. It only prevents further damage and subsequent blindness.
- Connie M Wu, Annie M Wu, Victoria L Tseng, Fei Yu, Anne L Coleman. Frequency of a diagnosis of glaucoma in individuals who consume coffee, tea and/or soft drinks. British Journal of Ophthalmology (2017). DOI: 10.1136/bjophthalmol-2017-310924