High coffee consumption, brain volume and risk of dementia and stroke | Hacker News Reader

High coffee consumption, brain volume and risk of dementia and stroke

tandfonline.com

109 pointsrobg128 comments

The article is not claiming causal link, but this is still interesting.

>After full covariate adjustment, consumption of >6 cups/day was associated with 53% higher odds of dementia compared to consumption of 1–2 cups/day

Coffee is stimulant just like some Alzheimer medications used to treat symptoms. It would be interesting to see if people increase coffee consumption with cognitive decline.

Considering the very early effects of dementia start to impact people sometimes decades before it becomes bad enough that they are diagnosed, it's certainly possible that extreme coffee consumption is some kind of self-medication mechanism.

Anecdotally, I've seen this a lot with adults with undiagnosed ADHD (including myself until 26). Caffeine can be a (very shitty) alternative to proper stimulant medication that people don't realise they actually need because of a medical issue. So the end up drinking 4-5 coffees a day instead.

I've been accused of self medicating with coffee before by a guy who was diagnosed with ADHD in his 40s.

It was funny at first, but then he started pointing things out. Want to ride bikes? We can get coffee on our travels.

I jest, kind of.

Not far fetched at all, seems there's been studies showing a correlation between ADHD and Dementia between genrations. A big question for me is if the ADHD was always even in the older generations there but was non-diagnosed?

https://news.ki.se/link-between-adhd-and-dementia-across-gen...

> A big question for me is if the ADHD was always even in the older generations there but was non-diagnosed?

Also could the absence of treatment be causal?

Undiagnosed people suffer immensely trying to cope and adapt to a neurotypical life. Depression and anxiety disorders are commonly found as comorbidities. The above-normal stress default by itself could probably explain all sorts of aging associated disease and symptoms, I presume.

Then you typically find issues with sleep, regular food and water intake ...

And yeah, in context, people with undiagnosed ADHD are much, much more likely to abuse drugs, or "self-medicate". Especially smoking and coffee.

Everything was diagnosed far less often in older generations, right?

Not so!

https://en.m.wikipedia.org/wiki/Female_hysteria

Wasnt this study made in the UK where most people lack vitamin D, which is also associated with dementia and depression?

It's 20% incidence in general, highest in Asian (Indian etc) communities - not completely correlated with melanin.

A bit of a sidenote, but I find it fascinating how little vitamin deficiencies are accounted for in allopathic medical contexts.

Deficiencies seem like such a frequent occurrence but most patients end up needing to self-medicate.

What are you talking about? Especially vitamin D is researched to death. You think scientists are stupid? If there is a incidence difference along the north-south axis, it's the first hypothesis investigated.

Thing is, intervention usually doesn't prove very effective. That's why doctors aren't that hysterical about it.

Then some vitamin supplement studies have shown actually harmful, eg. vitamin A as antioxidant. Vitamin D is a hormone and regulates many processes in the body, e.g. a large dose suppresses the immune system similar to steroids... caution is definitely warranted, instead of blanket recommendations of the "Just take 5000IU/d! #YOLO" you find online frequently.

I didn't say researchers, I said in a medical context. If you do a search on pubmed or Google Scholar, you can find a lot of research on how vitamin D supplementation proved beneficial for patients in different contexts.

Also, I found your reply really jarring. Perhaps it's the immediate ad-hominem attack, but I just wanted to note that for your reference, it really didn't motivate me to want to engage any further with you.

Good thing I also mentioned doctors, who are, of course, applying the concluded result of research. But maybe you are talking about another "medical context".

I threw your "vitamin D supplementation proved beneficial" into Google and this Nature review article on vitamin D supplementation was the first result:

* https://www.nature.com/articles/s41574-021-00593-z

Here is some additional reading you may find interesting:

* https://en.wikipedia.org/wiki/Ad_hominem

>alternative to proper stimulant medication

Nicotine will do it too.

Nicotine is a lot harder to stop though.

I drink two cups a day, but I must have them. Self medication. I can't imagine five cups, I wouldn't have time to fit them in. Perhaps I'm a lite-weight.

Make stronger coffee

extreme coffee consumption is used to self-medicate ADHD symptoms as well.

> Anecdotally, I've seen this a lot with adults with undiagnosed ADHD (including myself until 26). Caffeine can be a (very shitty) alternative to proper stimulant medication that people don't realise they actually need because of a medical issue. So the end up drinking 4-5 coffees a day instead.

ADHD medication is among the hardest to get in the first place, and to maintain in many places.

I was diagnosed as a child, and still couldn't get regular medication until 3 years ago (I'm 37 now). Doctors will try to push off-label treatments, often SSRIs, which do nothing for ADHD. They will push people to try ineffective talk therapy and describe actual medication as "only a last resort".

My cousin can't get it because his insurance says you only have ADHD if you were diagnosed as a child, and he spent his childhood in another country where the roads were barely maintained.

ADHD meds reduce the chances someone will abuse drugs according to research, but many docs will cancel prescriptions if you are honest about cannabis use.

In the wake of the opiate scandal new restrictions also place limits on how much a pharmacy can dispense, even if everyone has a valid prescription. That's part of the reason for the medication shortages in some areas.

It's been a miracle medication for me, but if you don't have money and luck it can be next to impossible to find someone to help you. Those that do often require thousands in fees.

To add: At least for methylphenidate, there are several studies showing neuronal long term improvements, "brain normalisation", in people with ADHD. That's rare in psychopharmacology...

I do understand hesitation about immediate release amphetamine, but the retarded formulations are also quite hard to abuse. If you do more than prescribed, you won't get high, you will have a bad time. "Getting high", requires a sudden onset, rush, and sharp peak, which retarded meds won't induce.

Denying people with ADHD to try stims, is really, really unethical considering our knowledge on their effectiveness treating the condition.

Especially considering how difficult it often is for ADHD people to follow through on subsequent visits.

True. That's a whole nother can of worms. You often only get something like 30 days worth of pills per prescription before you have to visit your doctor again. For someone with poor time and tasks management, those 2-3 hours lost (and adding the "resources" spent on mental overhead/stress/anxiety), are actually a significant burden.

ADHD is also very strongly linked to cigarette smoking, by the way. What I mean is that nicotine is a form of self-medication

I'm wagering that these people are just chronically under-slept, using higher amounts of coffee to compensate. The link between chronic poor sleep and dementia is well established.

Doesn't coffee impact sleep quality as well? At 6 cups a day, I'd expect some caffeine left in the body when sleeping.

Twelve hours to metabolize. The six cup people are totally jacked.

Half-life of six hours, so after twelve hours, one quarter of the caffiene will still be in the blood.

Tolerance kicks in. I can drink a double espresso after a dinner and still sleep like an angel.

Perhaps, but do you really know if and how much REM sleep you are getting? I've seen some things that link dementia more specifically to quality of sleep and REM time.

Caffeine consumption does lead to poor sleep.

Makes sense then that lots of coffee would lead to many nights of low quality sleep thereby increasing the risk of all sorts of bad health outcomes

I suspect it's the other way around, or a cyclical effect. Plenty of people simply do not allow themselves a full night of sleep, or feel that they cannot afford a full night of sleep (e.g. working 2 jobs & raising kids), leading to dependence on caffeine for functioning.

Yeah it’s probably some kind of feedback loop. Over time the loop leads to more and more caffeine consumption and worse and worse sleep.

I can tell you from personal experience it’s not a good thing to have happen to you. Once I reduced my coffee intake to 0 cups a day my sleep became so happy and blissful.

Alas I’m back to drinking 1-2 cups a day. I hope I never go back to that feedback loop so I make sure to only drink coffee in the morning or early afternoon. Never later on in the day.

The problem with caffeine is not only the length of sleep but also that it negatively effects the quality of sleep.

So you not only sleep less hours but those hours won’t be as effective for the body and brain.

That is interesting. I wonder if it's simply the cadmium and lead found in coffee concentrate in heavy users.

Another potential causal mechanism might be that people in cognitive decline have their "daily cup of coffee", forget they've already had it, and then have another.

I was thinking the same, it's very interesting which way the arrow points.

Am I saying that because I drink an enormous amount of coffee and really don't want to stop? Yes.

But also.. because I hope my high coffee drinking is because of my vanishing brain, rather than the cause of it ;)

I've also read, several places, that sleep deprivation correlates very highly with alzheimers.

People with trouble sleeping tend to be people with trouble staying awake.

And those people generally reach for coffee.

there's also the reverse, coffee interfering with sleep as well.

EDIT: add a link:

https://www.health.harvard.edu/blog/sleep-well-and-reduce-yo...

Fun aside note: To read their privacy policy, you have to agree to their privacy policy.

The anger caused by such idiocy incrases the risk of headaches and strokes.

for the sake of health i recommend browsing the interweb not without ublock origin and annoyances filterlists enabled.

Not exactly.

To read their Privacy Policy, you need to agree to their Cookie Policy. To read their Cookie Policy, you don't need to agree to anything.

They drunk too much coffee apparently.

Coffee and tobacco consumption is a known correlation (one of many refs https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4158991/). Curious to see if authors considered that, as tobacco is one of the main aggressors of vascular tissue, which causes dementia in the long run.

EDIT 1: Just in time, UK Biobank (almost 500.000 people) study pointing to increased longevity with coffee consumers, an interesting controversy that just doesn't fit with their smaller study conclusion (although overall longevity is a different outcome, you would expect to find more dementia in older people) https://www.hsph.harvard.edu/news/hsph-in-the-news/coffee-lo...

Is it to tobacco because of nicotine? Or would things like nicotine gum and lozenges not count. I thought I recalled nicotine potentially being neuroprotective wrt dementia.

> consumption of >6 cups/day was associated with 53% higher odds of dementia compared to consumption of 1–2 cups/day (fully adjusted OR 1.53, 95% CI 1.28, 1.83)

6+ cups! That’s a cranial marinade.

My mom, both of my sisters and I drink it by the pot. Each of us, every day.

6 cups? That doesn't sound like enough coffee to me.

I can’t even drink a single cup of coffee without shaking and getting intense anxiety.

Perhaps someday we'll discover a coffee tolerance gene.

The gene is called CYP1A2 with two variants. One variant is a rapid caffeine metabolizer. The other is a slow caffeine metabolizer. https://www.geneticlifehacks.com/liver-detox-genes-cyp1a2/

I have the rapid variant but could not sleep well on 6 cups.

That is interesting information. I note that the same enzyme breaks down melatonin. If a variant that is particularly efficient at caffeine is also particularly efficient at breaking down melatonin, the symptom would be difficulty getting to sleep independent of amount of caffeine, which is totally fixed by taking melatonin tablets.

Slow metaboliser here. If I drink a coffee at 11am my heart rate rises and doesn't return to normal until the following morning.

There are other genes for it too, like one that affects the degree to which coffee causes anxiety. And plenty of others that we haven't found, presumably.

I love love love love coffee. It took me years to realize that my high blood pressure was controlled almost immediately by cutting out a high-test canned “Draft Latte” drink. I can drink a single 8oz cup every few days. Decaf is fine.

6 cups are scrub numbers, if you haven't done that by 10am you're behind the curve :P

>My mom, both of my sisters and I drink it by the pot. Each of us, every day.

Can I ask how's your sleep?

Sleep was fine. I used to drink it by the pot but I cut back mainly because I'd have to piss too much.

Yes, this is my main motivator when I cut back.

If I have to drive a long drive, as an example, I’ll skip coffee that day. I’d rather save stops.

I seem to sleep as well as I always have.

I go to bed when I am tired. Usually 11pm-1am. I fall asleep in a few minutes. Then I wake up about 7am, feeling OK. Closer to 6 hours is more normal for me.

I’ve been like that since I was a teenager and I didn't drink coffee then.

That’s like a little more than 2 venti Starbucks.

> more than 2 venti

Americans will do anything to not use the metric system :)

Venti is the Starbucks name for their largest size cup, which holds 20 ounces.

Most people don't really care about the exact, specific volume of fluid, they just go by whatever the cup size happens to be called.

At least it is more descriptive than the grande or short cups, or the small / medium / large at other places (even if you have to know that venti is 20 in Italian to make the connection).

I doubt I'm the only obnoxious country dude who rolls into Starbucks and orders a "large". You can ignore their pretentious names, they're very accommodating.

Too insecure to use the size names. That's how it plays...fyi

It's probably more that you don't want a corporation to dictate how you describe (brand) the sizes of a drink where we have near universal language for that purpose already.

Too much experience with cattle and thus not longing to resemble them. One of 'm says 'moo' and soon the rest follows. Now just imagine a ${city_equivalent_of_field} full of city folk where one of 'm says 'venti' and you understand what I mean.

They don't usually advertise it, but you can get a smaller cups than on the menu too. I prefer an 8oz size.

I order from the app, I think both the barista and I prefer to reduce talking. :)

Hell Yeah!!

Haha! I was just thinking that I see people drink like 3-4 of those huge coffees a day. I am a true American Metric Patriot.

The scientific definition of a 'cup' of coffee is important. Usually this is defined as 4 ounces of brewed coffee, which means a normal mug of coffee (which can fit something like 10 oz) would be 2.5 cups!

So, for most people's definition of a 'cup' of coffee, they really only mean 2.5 'mugs' of coffee.

And surely the amount of water is inconsequential, why can't we just use grams of actual coffee? Then we don't have to worry about how many espressos are in a 10oz mug. (Nevermind what that person's considering a standard dose for the espresso!)

Measuring extraction ratio on coffee is difficult and wildly varies based on preparation method. The standard “cup” assumes 4oz of coffee, using 5oz of brew water (so, 1oz stays in the coffee grounds as waste). I believe there’s also a standard amount of coffee grounds used as well, though.

Different brew methods extract differing amounts from the coffee, so the amount of water is indeed consequential. Same grams of coffee in to a pour-over vs espresso would result in different amounts of extracted coffee material consumed.

True. I'm inclined to think it would be closer than 'do whatever you want in order to end up with an Xoz drink' though!

Prep method matters so much though. For comparison, a standard double shot of espresso is typically 18g of coffee. This would yield approximately 110mg of caffeine.

By comparison, the same 18g brewed using a pour over method should yield an 8oz cup of coffee with … likely around 170mg of caffeine.

Check out this James Hoffmann video specifically on this topic: https://youtube.com/watch?v=etnMr8oUSDo

I remember reading somewhere that the amount of caffeine in the cup is also proportional to the brewing time, therefore an espresso may not actually contain that much caffeine in the end (for the same initial amount of ground coffee, of course)

When I was in Organic Chemistry in College we demonstrated this experimentally. A cup of drip coffee had more caffeine than a shot of espresso. We were college kids so I'm not sure how consistent our how methodology was but the result was pretty consistent across all of us.

True but I think the coffee machine definition of 4-5oz per coffee “cup” usually also assumes a stronger European strength of coffee which is quite concentrated. Most Americans seem to make coffee larger but more watered down, so it could be back to a 10oz mug is 1 or 1.5 cup equivalents.

Americans drink very watered coffee though compared to most of the rest of the world. For us that came from abroad, it is basically tea.

This survey is using self-assessed cups - without providing a cup size or any guidance. Specifically, a survey asks users "How many cups of coffee do you drink a day?" with no other context.

So, "cups" for this study is whatever the respondent considers a cup. For most people, that's going to be at least 8 ounces and probably 8-12 oz.

From the full text (https://ore.exeter.ac.uk/repository/bitstream/handle/10871/1...), here's how the intake is described:

> Habitual coffee intake was self-reported as cups per day, as part of the touchscreen questionnaire at baseline with the question “How many cups of coffee do you drink a day?” (38). Participants were asked to include decaffeinated (decaf) coffee intake in their response. Decaffeinated consumers were identified from response to the question “What type of coffee do you usually drink?”. Coffee consumption was grouped in seven categories, including non- drinkers, decaffeinated coffee drinkers, and caffeinated coffee drinkers consuming <1 cup/day, 1-2 cups/day, 3-4 cups/day, 5-6 cups/day and >6 cups/day. “Coffee drinkers” in the text refer to participants who report intake of caffeinated coffee. For sensitivity analyses we constructed separate indicators restricting the data to decaffeinated coffee drinkers and according to tea consumption, using intake categories as above"

I used to drink one liter of coffee a day, and I would prepare it in a measured cup by the way so it's not an exaggeration.

I used to drink along the lines of this much coffee or more. I was travelling very often and often working 12+ hour days for weeks on end. I look back on those days and just thinking about it reminds me of my constantly tweaking eyes, lack of sleep, constant hyperactivity, anxiousness, stress etc.

I stopped cold turkey for a while but nowadays have settled on more like 1-2 a day and never after a specific time of day (for me I hard stop at 3pm). Having any more than this or after this time kills my sleep immediately.

Decaf is something I’ve really started to enjoy over the last couple of years. I’ll have one mug of actual coffee in the morning to start my day and then anywhere from 1-3 mugs of decaf. Back in the day it was not an equivalent option due to the chemical extraction process making it taste inferior. Now with water processed beans being offered with my local roaster it’s just about the same level of taste

Great album title, Cranial Marinade.

Coffee & Tea are both stimulants. So I wouldn't be wrong by coming to the same conclusion about tea drinkers. Guess my cranium has been marinated real good.

I can't access the article. Can somebody tell me what is "a cup" mentioned in the article? How much water and how much caffeine is in one "cup" in this article?

All the comments here mentions different number of "cups", but I'm very worried that all are different "cups"

I've looked for this, the BioBank screen is this: https://biobank.ndph.ox.ac.uk/showcase/refer.cgi?id=100319 There is literally no guidance AFAICT. My best estimate is 8 US fl oz as per ChatGPT British still use cups to refer to that sometimes. And caffeine... it varies even from cup to cup, the estimate of 91mg per 8 oz cup is what I use.

Per the article, "Habitual coffee intake was self-reported as cups per day, as part of the touchscreen questionnaire at base line with the question ‘How many cups of coffee do you drink a day?’ "

Sounds like it's based on the colloquial definition, which means... who knows! Self-reported values are very non-specific, since my definition of a 'cup' could mean a 24oz with an added triple shot... or it could mean a weakly brewed cup of instant coffee.

It will average out, so we will need to ask a British person what size an average cup of coffee is.

Brit here, an average cup of coffee would be around 1 heaped tsp of instant coffee in a 300ml mug with a bit of breathing room, say 275ml? But that would include the milk, so maybe around 200ml water and 75ml of milk. Would vary quite a lot from person to person though.

That'd be around 57 mg caffeine. On the weak side, compared to espresso or drip coffee. You think the most common preparation is instant coffee? Kind of surprising.

In the UK? Yes. I think in the UK, most people drink most of their coffee at home rather than out at a Starbucks or similar.

Some folks have a percolator or a cafetière or a fully automatic, especially younger people, but if I were to be invited round to meet someone’s parents, I’d expect instant.

To be fair, I haven’t lived in the UK for over ten years now, I can imagine Nespresso type machines may have taken the lead.

Not necessarily. If people are differentially biased to report higher cup counts when their actual caffeine strength is lower (because, for instance, they drink 6 cups of instant coffee), then that will have large implications on the study. Controlling for caffeine content is extremely important.

Sci-Hub link[1] to the paper.

I think it's safe to conclude that a cup here is in UK terms:

> Individuals aged 37–73 years were recruited in 22 assessment centres across the United Kingdom, between 13 March 2006 and 1 October 2010.

[1] https://sci-hub.se/10.1080/1028415X.2021.1945858

A cup of coffee can be something very different from person to person and situation to situation.

Espresso? Weak americano? Strong? And then even: there is often more caffeine in a cup of filter coffee than in an espresso. Weird but true. So it differs quite a lot what you drink.

I know someone who drinks 15 cups a day, but they are very very weak. And another drank 20 stong ones a day. Myself I used to drink 10 easily, not anymore

Even the same volume(cup) of coffee brewed the exact same way will vary in caffeine content based on whether it's a light or a dark roast. I wish more studies like this would just list mg of caffeine for comparison instead.

Caffeine does raise blood pressure. You also drink more of you don't sleep enough. Who knows.

And, it significantly disrupts sleep if you drink it 6 hours before bedtime [1]. Poor sleep is linked to dementia [2] risk.

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3805807/#:~:tex....

[2] https://www.harvardpilgrim.org/hapiguide/understanding-the-c....

The lack of a result for stroke tells me that this is just a fishing expedition.

I drink about 8-10 cups of black coffee a day, which is what my brewer makes.

I don’t have any issues with sleep but I don’t feel any sort of boost from it, I just enjoy the way it tastes.

I’m curious how consistent this can be seeing as coffee can be made so differently. I know the coffee I make at home is incredibly weak compared to what you’d get at a cafe. I use about 2-3 tablespoons of freshly ground beans for those 10 cups. Starbucks tastes like they use double that for a cup.

I can’t imagine I consumed that much coffee despite the large number of “cups”.

Sorry, I have to get clarification - do you use 2-3 tbsp per cup, as in 20-30 tbsp for the pot, or 2-3 tbsp for the whole pot? The one sounds like normal coffee, while the other would almost be water in my books.

I use 2-3, maybe 4 for the 8 cup brewer. I drink it weak. lol

“Cups” as in “coffee maker cups”, ~4oz per “cup”, vs cups as in measuring cups (8 oz)

1.3 Liters, so I guess they’re considering a cup in my 8 cup brewer as 5oz.

So my habit of putting in a lot of effort to prepare 1 or 2 cups of coffee per day puts me at the local minima for risk of dementia and stroke?

Excellent.

Now, while gloating about how this study matches up with my own biases, I would like to take a moment to remind everyone:

This is a single study, ignore it, wait for a meta analysis and then ask your local expert in that specific field to interpret it for you. Or, better yet, wait for a book covering a number of meta-analyses.

Single studies are not helpful for general consumption!!!

Should I consume 1-2 meta-analyses per day, and is there any risk associated if that number increases to 5+?

Could coffee be a proxy for a high-stress, mentally-taxing, low-sleep-quality lifestyle? How did they take their coffee? With lots of sugar?

Full text: https://ore.exeter.ac.uk/repository/bitstream/handle/10871/1...

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--- About the subject, could be indeed that people with early dementia, have sleep deprivation so they need more coffee...

It would be interesting to see comparisons to tea and decaf coffee, correcting for the amount of caffeine in those beverages. They seem to be assuming caffeine is the causal agent here, in which case there should be detectable parallels with other caffeinated beverages.

I switched over to fully decaf coffee earlier this year.

One of the coffee roasters nearby me highlighted their decaf single origin and thought to try it on a whim one day. It was so good, I stopped drinking decaf coffee that day and bought three bags of the stuff.

It's been two months since I did this. The biggest benefit I've noticed was feeling how insanely tired I am. Fortunately, I've been working on that problem, but damn, coffee really covers up sleep deprivation well.

> I switched over to fully decaf coffee earlier this year.

You may want to rethink.

>The association between coffee consumption and dementia was..

> with evidence for higher odds for non-coffee and decaffeinated coffee drinkers and those drinking >6 cups/day, compared to light coffee drinkers.

Still experimenting with about ~20mg of coffee every other day. Great as part of my pre-workout (as indicated by Huberman's podcast) especially with fats. If I don't add the fats, I definitely feel the edginess and jitteriness...

I don't really need it though, wondering if I'm better off just avoiding it? Heard of many other longevity and neural benefits... something I was expecting in this pretty empty study. Self-experimenting continues...

Well even this study shows reduced risk with moderate consumption compared to the 0 or the 6+ group.

Stupid publishing model from the dark ages https://ore.exeter.ac.uk/repository/bitstream/handle/10871/1...

More and more of these "studies" are popping up, using the UK health database to make hypothesis to what we eat or drink, without really diving into the "why".

I know it's a nice first step for more thorough research proposals, but I think they tend to freak people out.

So the takeaway is that more than zero but fewer than six cups is better than none or greater than six cups?

We need to know whether this means real cups for the bullshit "cups" commonly used to measure coffee were used in the study.

Is this just related to caffeine, or coffee in general? I drink a LOT of decaf, which probably ends up being 2-4 cups of "real" coffee.

Decaf has less than 10% the caffeine of regular coffee, if I recall correctly. Are you drinking 20 cups of decaf a day?

I'm not sure. I have 2-4 of those standard re-usable "to-go" mugs day. Which is probably (hopefully) less than 20!

Not controlled for: Heavy caffeine consumption affects sleep, and sleep quality is correlated with cognitive declines.

Did a Find on the word "exercise" in the article and comments. Result: Not Found.

Just had Death Wish coffee for the first time. This is gonna be interesting.

Just had another coffee...darn, forgot what I wanted to write ;-)

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