Is coffee HARMING your vision? Latest research

is your daily coffee habit making you slowly go blind in this video I'm going to review the latest research to figure out if drinking coffee is harming Your Eyes by the way I'm Dr Michael Chua I'm a board certified opthalmologist with poy Hills Eye Care and I make videos to help you see better look better and feel better too coffee which is a daily ritual for some of us contains caffeine the world's most commonly consumed psychoactive substance how does it work caffeine acts by blocking adenosine an inhibitory brain neurotransmitter leading to increased brain activity alertness and the release of neurotrans miners like neopine phrine and dopamine we've all experienced that morning jolt it's the caffeine at play numerous Studies have highlighted caffeine's short-term cognitive benefits including improved mood metabolism vigilance and cognitive function but excessive caffeine intake can result in issues like jitteriness anxiety heart palpitations and worsen padic attacks the connection between coffee consumption and your eyesight is complex with individual responses varying research from 2012 has shown that excessive coffee intake particularly in individuals with a family history May raise the risk of glaucoma it's a clear reminder that when it comes to Coffee moderation and personalized approaches are key especially if you have a family history of certain eye conditions your unique genetic background can play a role in how coffee affects your eye Health let's first quickly review what glaucoma is glaucoma is an eye condition characterized by damage to the optic nerve and it's usually associated with high eye pressure it can result in vision loss and even blindness roughly 3 million Americans live with glaucoma making it a significant Health concern worldwide it ranks as one of the leading causes of blindness at least half of those affected by glaucoma remain unaware of their condition as the early stages often exhibit no symptoms vision loss from glaucoma usually starts in the peripheral vision affecting our ability to see what's on the sides when we're looking ahead as the condition progresses the vision loss can spread to our central vision which is crucial for a task like reading driving and looking at our loved ones faces the good news is that through regular eye and vision screenings glycom can be detected while treatment cannot fully restore lost eyesight it does hold the potential to slow the disease's progression and prevent further vision loss okay let's bridge the gap between coffee and glaucoma in this 2012 study researchers from Harvard Medical School wanted to investigate whether there was any association between coffee consumption and the risk of having a particular subtype of glaucoma called exfoliation glaucoma I also want to give a quick shout out to Dr Pasqual he was the lead author of the study and one of my professors in residency he actually taught me how to perform laser treatments for glaucoma so why did these researchers decide to investigate coffee and this particular subtype of glaucoma called exfoliation glaucoma well exfoliation glaucoma is a type of glaucoma that's characterized by the accumulation of microscopic flaky material on the ey's internal structures and this material clogs up and blocks the normal drainage of fluid from the eye this obstruction leads to elevated intraocular or eye pressure causing optic nerve damage glaucoma and resulting in vision loss exfoliation glaucoma is most commonly found in northern European countries like Iceland and Sweden and research has shown us that changes in a specific Gene called the lock L1 Gene strongly increases the risk of developing exfoliation glaucoma but stud Studies have found that these locks L1 Gene variants are not only found in people from those northern European countries like Iceland but also in places like China Saudi Arabia South Africa and Latin America the interesting thing is that even though these particular genetic alterations are found all over the world for whatever reason the disease just happens to be more prevalent in those Northern countries like Sweden for example a study found that the prevalence of exfoliation syndrome in Iceland Finland and Sweden is in the range of 20% or greater while in a place like Sri Lanka the prevalence is 1% so scientists like Dr Pasqual have been working to understand if there are any other factors at play things like environment or lifestyle factors that are also pulling the strings and increasing someone's risk of developing exfoliation glaucoma and if you look at a map of coffee consumption per capita it's interesting because the countries that have the highest coffee consumption also happen to be the countries with the highest prevalence of exfoliation glaucoma in this map Darkly shaded countries are the countries with the highest coffee consumption and so you see places like Iceland Finland and Sweden where coffee consumption is among the highest in the world are also the places where exfoliation glaucoma rates happen to be the highest in the world okay that's fine there may be an association there but just because a Swedish person likes to drink more coffee doesn't mean that the coffee is causally increasing the risk of glaucoma what if the connection is actually more related to their different genes or the colder temperature of their environment or their diet well first you need to at least establish some sort of biological explanation some mechanism that could even make it theoretically possible that coffee Kickstart some sort of biological process that can increase someone's risk of getting glaucoma well multiple randomized control TRS have shown that coffee increases levels of an amino acid called homosysteine throughout the body and increased homosysteine levels have been found in the bloodstream and in the eyes and tears of patients with exfoliation syndrome the theory is that elevated levels of homoy have been shown to cause stress and damage to cells in tracular mesor which is the structure that allows fluid to drain out of the eye so if these cells are injured and fluid can't flow out of the eye properly pressure can build up and cause glaucoma elevated levels of homocysteine in the eye have also been shown to impair metabolism and retinal cells and causes them to be more vulnerable to cell damage okay so we understand what exfoliation glaucoma is and that there's some sort of biological possibility that coffee can cause increased risk of glaucoma now let's look at what the study showed the study examined the relationship between coffee consumption and the risk of having either exfoliation syndrome or you have that white flaky material inside the eye seen on exam or exfoliation glaucoma where you now have demonstrable damage to the nerve researchers completed a rigorous analysis of 78977 female and 41,42 male US registered nurses and health professionals they examine each subject's coffee consumption habits as well as the results of their eye examinations from 1980 all the way through 2008 so this is over a 28-year period so in order to quantify patient coffee consumption all these subjects completed dietary intake questionaires every four years so researchers can get a snapshot of the typical things people ate and drank such as how how much coffee or tea they drank in order to measure how many of these people had glaucoma each person filled out a question here asking them whether they had been diagnosed with glaucoma if a research subject answered yes then the researchers would contact the patient's eye care provider and obtain all of their records and review them to confirm whether they truly did have exfoliation glaucoma a key strength of this finding was that they followed many people we're talking over 110,000 people over nearly 30-year time period a very long time it's quite rare to have studies done on this big of a scale both in terms of the number of subjects as well as the length of followup when they crunch the numbers they found that people who drank three or more cups of caffeinated coffee per day had a 66% increase risk of having either exfoliation glaucoma or being an exfoliation glaucoma suspect and the difference was statistically significant in a subgroup analysis they found that there was an even stronger association between coffee consumption and risk of having exfoliation glaucoma in women and also in people who had a family history of glaucoma and lastly they only found this Association of increased risk with caffeinated coffee consumption they did not find any significant association between consumption of caffeinated soda caffeinated tea decaffeinated coffee or chocolate with an increased risk of having exfoliation glaucoma now before you go and spit out the coffee you're drinking let's remember that there are some key limitations to the study as well first they based their measurements of coffee consumption on questionnaires of patients done once every four years you can imagine how difficult and inaccurate it can be for you to try to remember all the things you ate and drank over the last few days or weeks ideally the researchers would be directly observing and recording how much coffee a person drinks every day but doing this for over 100,000 people for over 30 years would become very challenging and expensive very quickly another limitation of this study and all Association studies really is that you can't draw a causal relationship between coffee and gloma just because they're strongly associated with each other it's possible that maybe the coffee drinkers happen to smoke more or drink more alcohol or maybe they tend to have higher rates of high blood pressure or maybe they're usually a little bit older so it's possible that it's not coffee drinking per se but maybe another variable that tends to be found in coffee drinkers that is actually moving the needle in terms of glaucoma risk these other variables are what we call confounding variables the researchers try to account for these confounding variables using statistical analysis called multivariant analysis for example the researchers in the coffee study reported that they accounted for other variables like family history of glaucoma age history of hypertension diabetes cholesterol heart attack weight smoking and alcohol this is actually a pretty good and extensive list of possible founding variables that they were able to account for but still it's impossible to account for every single other variable in someone's life in an ideal hypothetical World they would set up a randomized control trial they would take many patients and randomly split them into groups they would have one group drink no coffee per day one group drink one cup per day and another group drink let's say three cups of coffee per day then they would directly observe these people to make sure they were drinking the prescribed amount of coffee per day then they would follow these people for many years and check their eye exams to see if coffee did in fact affect ffect the patient's risk of developing glaucoma you can see how logistically difficult this would be it would be hard to basically force people to drink a certain amount of coffee every day and it would be difficult to directly observe them for so many years so scientists just do the best they can with the resources they have to try to design experiments that can help us get closer to the truth one last point about this study is that they were looking at a particular subtype of glaucoma called exfoliation glaucoma by far the most common type of glaucoma we eye doctors see in the office is called primary open angle glaucoma which is characterized by an open drainage angle and damage to the optic nerve but remember this study investigated a rarer subtype of glaucoma called exfoliation glaucoma Which is less common than primary open angle glaucoma so you can't use the results from the study to make any conclusions about risk of coffee consumption on developing primary open angle glaucoma and again the reason why they chose to investigate exfoliation glaucoma was because of the biological mechanism that increased coffee consumption may increase homoy levels in the body and these elevated homocysteine levels are theorized to to possibly increase the risk of developing exfoliation glaucoma but even with these limitations these large scale Association studies are very useful starting point when trying to identify what lifestyle habits actually move the needle in terms of affecting your risk of developing glaucoma for example these researchers found a positive association with caffeinated coffee but didn't see an association with tea chocolate or decaf coffee with increasing glaucoma risk now that they have this starting point though scientists can go on to develop more rigorous clinical trials to investigate this relationship further one interesting find they noted in the study was that positive family history made the association between coffee consumption and glaucoma risk even stronger making them question whether there was also a genetic component to someone's vulnerability to Coffee increasing the risk of developing glaucoma so in 2020 many of the same researchers from this study including my professor Dr lisis Pasqual published a follow-up study in the journal Opthalmology before we dive into the details of our second study I wanted to tell you about my optimized newsletter if you want science back tips on how to protect your vision and health delivered straight to your inbox you can sign up for my optimized newsletter at Michael Chu md.com okay back to the research in this 2020 study researchers wanted to investigate whether coffee consumption affected average eye pressures and whether it had any effect on developing glaucoma not just exfoliation glaucoma but glaucoma in general they looked at 12137 4 people who were registered in the UK biobank the UK biobank is an incredibly valuable database of patients that researchers have access to again huge numbers in the study as well they're looking at over 120,000 people the subjects in the study all filled out questionnaires answering how much coffee and tea they drank daily these subjects also answered whether they had been diagnosed with glaucoma and all of them received an eye pressure check the other key thing was that all the research subjects donated blood urine and saliva samples so researchers had access to their DNA so after putting all the data together here are the key results they found they actually saw that greater caffeine consumption whether through coffee or tea was associated with lower intraocular eye pressures they also didn't find any relationship between caffeine intake and glaucoma risk but they they also did some interesting analysis with all the DNA information they had from research subjects previous Studies have identified specific Gene variants that are associated with increased eye pressure and increased risk of glaucoma when the researchers looked specifically at people who had the particular genes which increased their risk of glaucoma the researchers found that those with a genetic vulnerability who drank the top 25% of caffeine had a 3.9 times increased odds of having glaucoma compared to patients who did not have the genetic predisposition and consume the least amount of caffeine and when the researchers compared only the patients with the glycom wrist genes they found that people who had the glycom wrist genes and drank the top quarti of caffeine had a 30% increase in the odds of having glaucoma compared to people who also had the glaucoma rist jein but consume the least amount of coffee so when we put all the results together it looks like generally caffeine consumption doesn't seem to significantly affect eye pressures but in some people who have a certain genetic makeup that makes them particularly vulnerable to glaucoma and in those people increasing the amount of caffeine they drink does seem to be associated with an increased risk of having glaucoma now bear in mind that this second study has many similar limitations to the first one it's an association study based on diet questionaries so you have to remember that some people may have difficulty remembering exactly what they drink and how much they drink on a daily basis and there's always a possibility of confounding variables but the study does still raise an interesting possibility that patients with particular sets of glaucoma genes may want to avoid drinking too much caffeinated beverages because it can raise the risk of developing glaucoma the problem though is that there are no publicly available genetic test kits or panels that allow you to know whether you have these particular glaucoma genes or not so none of us really know whether we're in that high-risk glaucoma group but one key piece of information that we can use to help guide our diet and lifestyle decisions is our family history remember in the first study we discussed from 2012 one of the findings that researchers reported was that when they analyzed the patients with the family history of glaucoma they found that there was an even stronger Association between coffee consumption and glaucoma risk so it's possible that in those patients with a family history of glaucoma those patients have the genetic predisposition to developing glaucoma which may make them more susceptible to an increase in glaucoma risk from coffee consumption this data implies that we may need to also incorporate genetic data from patients in order to provide useful precise nutrition recommendations this is because our genes affect how what we drink or what we eat will affect our risk of developing certain conditions like glaucoma so if you do have a family history of glaucoma maybe you should spit out your cof after all if you find the information of this video helpful don't forget to subscribe to the channel for future updates and if you live in the Los Angeles Orange County or Inland Empire area and want to get your eyes checked feel free to visit our website or give our phone number call to make an appointment today by the way if you made it this far into the video that probably means that you're really interested in protecting your vision and health check out the best ways to prevent glaucoma by watching my video here I'm Dr Michael Chua with pente hills iare see you next time

Channel: Michael Chua, MD

Views: 12,313

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Id: 2Ctz9gUGtuQ

Length: 14min 54sec (894 seconds)

Published: Fri Dec 15 2023