Coffee and Kidney Stones: What's the link and how to prevent kidney stones!

Welcome everyone to own principles. This week I wanted to address a question I get asked a lot and it has to do with

kidney

stones

and

coffee

. As you know, I have done several podcasts and videos about the benefits of

coffee

, but many people with

kidney

disease ask well,

what

about kidney

stones

? Let's look at the evidence and see if we can't answer that question. With that, let's dive a little into the background so you know

what

kidney stones are all about first. It is important to understand the kidneys. Stones are actually quite common, about 15 percent of about one in seven people have kidney stones, some have recurring kidney stones, and some have so many kidney stones that they simply cannot get rid of them and can have serious complications, including kidney damage and even in rare cases dialysis now common symptoms of kidney stones are things like pain in the side or pain right in the back some people notice blood in their urine some people have vague symptoms like a little nausea, a little urgency. when they urinate, they have an infection due to the stone, they may feel pain when urinating, so stones in the urine can have very large symptoms and often, and sometimes even smaller symptoms, which you may miss.

In terms of stone types, there are about five main types that you want to understand with the most common being calcium oxalate, which accounts for about 70 to 80 percent of people who have stones. It's usually calcium oxalate, then there's calcium phosphate, which is 15. Now calcium phosphate is very unique compared to calcium oxalate because it requires a very different pH. Calcium oxalate likes an acidic environment, but the Calcium phosphalate actually likes an alkaline environment. The third type of stone is uric acid, which represents approximately eight percent of the stones that exist and occurs in people who have a high consumption of purines.

Purines are generally found in viscera similar to shellfish and what happens when a high content of purines is ingested is converted into monosodium uric acid and monosodium urad is converted into uric acid and that is the element that causes stones. The fourth type is struvite and are generally related to upper urinary tract infections. It happens and many times there are common bacteria that produce urease and that bacteria is a species like proteus klebsiella pneumonia corny bacteria urea plasma uraliticum and what happens with struvite stones are sometimes associated with what is called triple phosphate, so they have calcium, magnesium and ammonium and lastly there is Cysteine ​​and cysteine ​​are quite rare stones so there is not much to worry about but they can occur and there are the same type of treatment options that we have discussed in the past.

Now the evidence on caffeine and stones is conflicting. There are positive and negative investigations. research let's get to the positive research so there is a study in 2021 that is a systematic review of 13 studies and what they said was that moderate coffee consumption does not increase the risk of having kidney stones in another study with ferraro and colleagues in 2014, what they looked at was the health professionals follow-up study, the nurses' health study 1 and 2 and they found that caffeine was independently

link

ed to a lower risk of kidney stones and then another study in 2013 showed that more than or equal to one serving per day of caffeinated coffee compared to less than one serving per week had a 26 lower risk of kidney stones, okay, that's the positive research so far, very good, But what about some negative research?

Well, Massey and his colleagues did a study where they looked at 39 patients with calcium oxalate stones. and what they did was they basically looked at urinalysis two hours before and two hours after caffeine consumption and what they said was that caffeine slightly increased the risk of calcium oxalate stone formation. Now remember these were people who already had calcium oxalate stones, so what that means was that you were seeing more calcium and oxalate getting into the urine, so there's another study with Sun and his colleagues and it was an improved survey from 2007 to 2014. and what they said was that there was a linear relationship between caffeine intake and your risk of kidney stone recurrence, so now you have positive studies, you have negative studies and the question is what is true, to really get an answer, what is What happens is that you have to understand the problem with all these studies, they have recall bias, there can be confounding factors. and if they really wanted to understand, they would have to do a randomized control study, which is difficult, takes an enormous amount of time and is extremely expensive and therefore it is very difficult to do randomized control studies, so the question is If we have something that can give you a better answer the answer is yes, then there is a study published in the American Journal of Kidney Disease in October 2021 that looks at this exact question regarding coffee and caffeine consumption.

It uses a method called a Mendelian randomization study. So what is this Mendelian randomization method? Basically, the idea is that by using certain genes, you can basically say that if that marker is strongly associated with what you're testing, then you can create a causal inference. In other words, in this study they analyzed 14 single nucleotide polymorphisms and each one of these polymorphisms is associated with coffee consumption. They now used a very large database: 375,833 individuals of European ancestry. It's called the UK Biobank study. They also use the Fingen study, which has 176,613 individuals. The idea was to use these unique ones. nucleotide polymorphisms that are related to coffee consumption, you could make a causal inference and the concept here is that because these single nucleotide polymorphisms are random in themselves, you get that randomization effect that you would get in a study of randomized control, that's a lot. complicated stuff, but it's good to understand a little bit about the Mendelian randomization strategy and how it can help, but remember that for this to work you have three key assumptions, those assumptions are, firstly, that whatever variable you're looking for for that marker genetic is genetics. snip has to be strongly associated with exposure, in this case coffee consumption, which is why using something like the UK biobank study is so important.

Assumption number two is that it cannot be associated with something else that is happening and the third assumption is that the generic variable that affects the risk of the outcome has to affect the outcome through the risk factor which is a complicated way of saying that basically If you're saying that stone formation is what you're looking for, then stone formation has to occur through caffeine consumption. and that caffeine consumption is related to the specific nucleotide polymorphism. Okay, science is too complex, you don't need to know too many details, but you can always look at it for reference.

So what did they find in this? In one particular study, what they found was that increasing coffee from one cup a day to one and a half cups a day reduced the risk of kidney stones by 40, from one cup to one and a half cups, that's it. what was needed and looking at it slightly differently. An 80 milligram increase in caffeine, which is roughly equivalent to one additional cup of caffeinated coffee, had a 19-fold lower risk of kidney stone formation, so in other words, very small increases in coffee were associated with a lower risk of kidney stone formation. risk of stones and what is the mechanism, so if you want to know.

The reason coffee is

link

ed to a lower risk of stones is because of a few things: First, caffeine has diuretic properties and by causing urine to flow, it

prevent

s waste from sticking together and forming stones, so The key here is if you drink coffee and make sure you stay hydrated you can reduce stone formation, of course if you are dehydrated then that's a different story. The second is that caffeine actually reduces the adhesion of calcium oxalate crystals to the cells that line the tubules of the kidney and, as a result of that. By

prevent

ing those crystals from sticking together, they can't stick there and form stones, they just come out of the urine.

Another thing is that coffee is rich in citric acid and citric acid is a very powerful stone preventative and lastly when it comes to something else. The factor that is also present in decaffeinated coffee is trigonalene. Trigonalene is basically an alkaloid found in coffee and has similar protective benefits against kidney stones as caffeine. As a result, both caffeinated and decaffeinated coffee can be considered to reduce the risk of kidney disease. Stones, now remember if you think about this study and say, "Well, what's the conclusion?" What I can take home is that this Mendelian randomized study which, if the assumptions are correct, gives a causal inference and that causal inference is that increased consumption of caffeinated or decaffeinated coffee is related to a lower risk of formation of calculations.

Thank you so much for watching and as always, please, I would really appreciate it if you hit the like button, hit the subscribe button, give us a review, we would really appreciate it, and as always, make sure you follow the proper principle of getting more sleep. , move more, practice gratitude and kindness, and eat a whole plant-based diet for optimal health. Thank you so much.