Getty Images
This Reuters story reports on an observational study showing a possible association between drinking caffeinated hot tea and lowering the risk of glaucoma.
The story does a good job describing the study design and the lack of treatment options for glaucoma. It also included comments from two independent sources. However, it fell short by not providing enough perspective on how many limitations can occur with this kind of research.
Glaucoma is one of the leading causes of blindness in the world and affects over 55 million people globally. Because vision lost to glaucoma can’t be recovered, much of the research focuses on either slowing progression once it is diagnosed, or preventing the disease by identifying and modifying risk factors. Given that the role of caffeine as a risk factor is controversial, well-conducted research that suggests a protective effect of caffeinated tea is newsworthy, though news stories need to be cautious not to overstate the measured benefits.
Tea is widely available and relatively affordable compared to other prepared drinks.
The story mentions that study participants who drank one cup or more of hot caffeinated tea daily “had 74 percent lower odds of having glaucoma” compared to those who don’t drink hot tea.
Our standard response to a statement like this is to ask, “74% lower than what”? A 74% reduction from an already-small number might not be very meaningful. Absolute numbers would have helped–here’s more about how to provide them and why this is important.
Only potential harm to be considered would be those people who respond to this study by abusing caffeinated tea thinking that more consumption might offer more protection from glaucoma. Excess caffeine can have deleterious health effects. Not including this unlikely scenario in the story seems reasonable.
This was a tough call, as the story does a good job explaining how the research was designed. But it should have been more clear that this was an observational study that can not establish cause and effect. Self-reported dietary information is also notoriously unreliable.
Two opthalmologists who weren’t involved in the study were interviewed, and we could detect no conflicts of interest.
The story does make brief mention of lifestyle, environmental and diet interventions that may influence glaucoma, but could have made it more clear that none of these have been proven to prevent glaucoma.
Other than water, tea is the most widely consumed beverage in the world.
Although there is existing research investigating the role of caffeine in glaucoma, this study specifically compared the effects of caffeinated and decaffeinated coffee, tea, and soft drinks on glaucoma. The story makes that clear.
The story does not appear to rely solely on the news release. It quotes two independent sources not affiliated with the study.
Systematic, Criteria-Driven
@chrishendel @HealthNewsRevu I believe that "What Would Gary Think?" should be a kneejerk response to any 'junk food causes blindness'-type single case.... 🥴
Comments
Please note, comments are no longer published through this website. All previously made comments are still archived and available for viewing through select posts.
Our Comments Policy
But before leaving a comment, please review these notes about our policy.
You are responsible for any comments you leave on this site.
This site is primarily a forum for discussion about the quality (or lack thereof) in journalism or other media messages (advertising, marketing, public relations, medical journals, etc.) It is not intended to be a forum for definitive discussions about medicine or science.
We will delete comments that include personal attacks, unfounded allegations, unverified claims, product pitches, profanity or any from anyone who does not list a full name and a functioning email address. We will also end any thread of repetitive comments. We don”t give medical advice so we won”t respond to questions asking for it.
We don”t have sufficient staffing to contact each commenter who left such a message. If you have a question about why your comment was edited or removed, you can email us at feedback@healthnewsreview.org.
There has been a recent burst of attention to troubles with many comments left on science and science news/communication websites. Read “Online science comments: trolls, trash and treasure.”
The authors of the Retraction Watch comments policy urge commenters:
We”re also concerned about anonymous comments. We ask that all commenters leave their full name and provide an actual email address in case we feel we need to contact them. We may delete any comment left by someone who does not leave their name and a legitimate email address.
And, as noted, product pitches of any sort – pushing treatments, tests, products, procedures, physicians, medical centers, books, websites – are likely to be deleted. We don”t accept advertising on this site and are not going to give it away free.
The ability to leave comments expires after a certain period of time. So you may find that you’re unable to leave a comment on an article that is more than a few months old.
You might also like