5 ms·

Many forms of dementia destroy dopaminergic neurons, and this process begins much earlier than symptoms of dementia itself manifest. From what I’ve gathered fro

Many forms of dementia destroy dopaminergic neurons, and this process begins much earlier than symptoms of dementia itself manifest. From what I’ve gathered from reading studies across the years, less dopaminergic capacity seems to be associated with less restful sleep. The conclusions of this study seem to have it backwards. It’s not lack of sleep that causes dementia, it’s early dementia that causes insomnia. Edit: it’s also possible that a third factor causes both of these. For example, both people low on dopamine and the sleep-deprived are likely to turn to coffee to keep them functional. If they drink too much coffee, they might accidentally poison themselves into dementia, because some of the Harmala alkaloids in coffee are neurotoxic and like to deposit themselves in brain fatty tissues for a long time.

gundmc 6y ago
Coffee causing dementia is a pretty shocking claim that I haven't heard previously. Do you have more reading on this?
- nsxwolf 6y ago
  I've always wondered if coffee studies are just something they give bored grad students to do. I've heard about what seems like hundreds of them in my lifetime and they contradict each other in cycles over long stretches of time.
  - crocsarecool 6y ago
    Same! One week it’s terrible for you. The next week it’s curing cancer. I just try not to have any past a certain hour so as to not interrupt my sleep.
  - ineedasername 6y ago
    The behavior of drinking coffee or not is also very socially mediated-- portrayal of coffee drinkers in movies, coffee as a common activity for preliminary dates, or to meet someone new at a cafe... All of this means that coffee drinkers are going to self select for various other features that add confounding factors. Imagine you were doing a study on marriage patterns: I wouldn't be surprised if "Drinks their coffee in the cafe itself" was more highly associated with being single. And the headline will read "Dedicated coffee drinkers less likely to find a partner"
- eurasiantiger 6y ago
  There’s something in (1), but it doesn’t address the entire spectrum of Harmala alkaloid neurotoxicity (2) (3). It has been shown that heterocyclic aromatic amines (which Harmala alkaloids belong to) indeed damage dopaminergic neurons (4). (1): https://hammer.purdue.edu/articles/thesis/Identification_of_Neurotoxic_Targets_of_Diverse_Chemical_Classes_of_Dietary_Neurotoxins_Neurotoxicants/12919016/1 https://hammer.purdue.edu/articles/thesis/Identification_of_... (2): https://onlinelibrary.wiley.com/doi/pdf/10.1002/ijc.20703 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ijc.20703 (3): https://www.sciencedirect.com/science/article/pii/S1570023203008742 https://www.sciencedirect.com/science/article/pii/S157002320... (4): https://academic.oup.com/toxsci/article-abstract/173/1/171/5575765?redirectedFrom=fulltext https://academic.oup.com/toxsci/article-abstract/173/1/171/5...
JamesBarney 6y ago
https://pubmed.ncbi.nlm.nih.gov/20182054/#:~:text=In%20the%20CAIDE%20study%2C%20coffee,decreased%20risk%20of%20dementia%2FAD https://pubmed.ncbi.nlm.nih.gov/20182054/#:~:text=In%20the%2.... this says coffee is associated with a reduced risk of dementia which is pretty much what I've read over and over again
- eloff 6y ago
  Thank you! I was freaking out about my beloved coffee addiction.
  - zikzak 6y ago
    Never blame the coffee.
    - eurasiantiger 6y ago
      That seems like a cognitive bias.
- eurasiantiger 6y ago
  That study conflates caffeine and coffee from the very first word in the abstract. I wouldn’t trust it at all — it’s like an article about CPUs but the writer doesn’t understand the difference between a processor (called CPU) and the rest of the stuff in the computer case (which, as a whole, is also called CPU).
  - heavyset_go 6y ago
    So I read the whole paper, and not just the abstract. The authors do not conflate caffeine and coffee in the meta-analysis, in fact, they cite several studies that document the association between coffee consumption and the reduced risk of cognitive decline.
    - eurasiantiger 6y ago
      Did you check whether those studies do this conflation? Were they epidemiological studies (which cannot prove causality), or double-blind randomized studies (which can)?
ckosidows 6y ago
Just coffee or anything with caffeine? I'm really curious for a source on this, considering how much coffee I drink weekly.
- pvarangot 6y ago
  If caffeine does it for you and need lots of it, eating just caffeine is probably safer than drinking a lot of coffee. Coffee beans have a lot of of other stuff and it varies from bean to bean and eating a lot of some of that stuff may not be good for your gut/brain/whatever. If you are "addicted" to coffee sometimes you will crave it if you do just caffeine, but this goes away after a while. Be aware also that if you want the antioxidants and other stuff in coffee beans eating just caffeine won't give you that.
  - eurasiantiger 6y ago
    There’s really no evidence that antioxidants are categorically good for you. Studies have found that some benefits of exercise are mediated through oxidative stress, and get impaired by antioxidant intake.
- eurasiantiger 6y ago
  Just coffee. You may have a MAOA VNTR that predisposes you to like coffee.
chubot 6y ago
I agree you have to examine both directions, and a common cause, but the article somewhat addresses that under "chicken or egg?" The headline is misleading. Big idea: a common cause may be jaw development and the resulting lack of breathing (during the day and during sleep) in large parts of the population. Jaw development has a strong claim to be the fundamental, common cause of poor breathing and sleep because it's derived from 2 fundamental differences between humans and animals: agriculture and speech. It's a long chain of causation, and took me awhile to learn about, but it may be what you're looking for. Of course it could also be the case that some people are just staring at screens too much before bed and getting poor sleep. But bad sleep is an epidemic and there is evidence of this all over the world, and going back hundreds of years. The books I reference tell of orthodontists from the 1800's who noticed this problem, etc. Our diets drastically changed, which caused poor jaw development, which causes bad breathing, which causes bad sleep (I learned about this from my dentist). There are many factors that restrict airways, including weight. Remember that the average American male is about 30 pounds heavier in 2020 than in 1960 (and similarly for females). It's hard to imagine that not having an effect of breathing and sleep (and thus dementia). But I think animals can be fat and still have plenty of air for breathing; the same isn't true for humans. Previous comment I wrote on this including recent books (2018-2020): https://news.ycombinator.com/item?id=23435964 https://news.ycombinator.com/item?id=23435964 That article is "fitful nightly sleep linked to chronic inflammation and hardened arteries". That is another correlation, not a causation. So I would suggest that bad sleep, inflammation, hardened arteries, and dementia have a common cause in jaw and airway development. This is a lot harder to see because it took place over 10,000 years and it takes 30-50 years to kill you. You can have bad breathing your whole life but still be functional. It's very related to tooth grinding/bruxism, which is an epidemic as well. Other threads on Hacker News: https://news.ycombinator.com/item?id=24247066 https://news.ycombinator.com/item?id=24247066
TYPE_FASTER 6y ago
> it’s early dementia that causes insomnia > If they drink too much coffee, they might accidentally poison themselves into dementia Oh crap
- didibus 6y ago
  I wouldn't take anyone making a comment on HN a source of accurate and truthful data. The HN bias can be at play. Which is the bias that we believe and trust a random comment on Hacker News more than a linked research study, or the body of experts around a subject (who don't comment on Hacker News).
jiofih 6y ago
Please don’t upvote this nonsense. Harmala alkaloids are found in tobacco, not coffee.
- guerrilla 6y ago
  I'm pretty sure harmine and harmaline are found in coffee too. I thought it was common knowledge but all I found were two papers so maybe not. 1. https://www.sciencedirect.com/science/article/abs/pii/S0024320505007514 https://www.sciencedirect.com/science/article/abs/pii/S00243... 2. https://www.sciencedirect.com/science/article/abs/pii/S0308814609013806 https://www.sciencedirect.com/science/article/abs/pii/S03088...
- eurasiantiger 6y ago
  They are found in both, in high concentrations. Tobacco smoke and coffee are the two most significant sources of Harmala alkaloids in the human diet. (Source: T. Herraiz)
  - jiofih 6y ago
    Well, they are found in everything, meat, soy sauce, beer, right? Tobacco is a much more common source. By the logic of your previous argument, eating yakisoba could lead to dementia. Interestingly, your source’s paper on this says that coffee protects against brain disease: > epidemiological studies have consistently shown that coffee drinkers have an apparently lower incidence of Parkinson's disease (PD), suggesting that coffee might somehow act as a purported neuroprotectant https://pubmed.ncbi.nlm.nih.gov/16139309/ https://pubmed.ncbi.nlm.nih.gov/16139309/ Either way, I’m not particularly interested in this subject, the point is that making wild medical claims without sources in an online forum is best avoided.
    - eurasiantiger 6y ago
      They are indeed found in many products, but the key is the exact nature of the specific substances. Do they inhibit MAO-A, MAO-B, or both? Are they irreversible or reversible inhibitors? Do they do other things like cause neurotoxicity? The Harmala family has dozens of compounds, some good for you (for example MAO-B inhibitors indeed prevent PD, because MAO-B inhibitors are used to treat it) and some bad, like some beta-carbolines that are indeed neurotoxic. Again, the total amounts are what matters. It’s much easier to take in too much MAOIs from tobacco and coffee than by eating meat. Something seeming to protect against one specific disorder does not mean that it protects against all diseases.
ineedasername 6y ago
In fairness to the study, it's only claiming an association, not a causal link.
tartoran 6y ago
The OP doesn’t suggest that coffee may cause dementia but was a possibility for sleep deprived and low on dopamine individuals drinking too much coffee to stay functional, exacerbating their sleep deprivation thus rising the prospects of developing dementia.
- eurasiantiger 6y ago
  No, I was explicitly suggesting that neurotoxic amines in coffee may be building up in some, possibly genetically predisposed heavy coffee drinkers, causing loss of dopaminergic neurons and ultimately dementia, or other neurological disorders. This exact mechanism has been shown to be the cause of a very common neurological disorder called essential tremor. Patients have a genetic predisposition for building up tremor-inducing Harmala alkaloids due to reduced metabolism.

gundmc 6y ago

Coffee causing dementia is a pretty shocking claim that I haven't heard previously. Do you have more reading on this?

nsxwolf 6y ago
I've always wondered if coffee studies are just something they give bored grad students to do. I've heard about what seems like hundreds of them in my lifetime and they contradict each other in cycles over long stretches of time.
- crocsarecool 6y ago
  Same! One week it’s terrible for you. The next week it’s curing cancer. I just try not to have any past a certain hour so as to not interrupt my sleep.
- ineedasername 6y ago
  The behavior of drinking coffee or not is also very socially mediated-- portrayal of coffee drinkers in movies, coffee as a common activity for preliminary dates, or to meet someone new at a cafe... All of this means that coffee drinkers are going to self select for various other features that add confounding factors. Imagine you were doing a study on marriage patterns: I wouldn't be surprised if "Drinks their coffee in the cafe itself" was more highly associated with being single. And the headline will read "Dedicated coffee drinkers less likely to find a partner"
eurasiantiger 6y ago
There’s something in (1), but it doesn’t address the entire spectrum of Harmala alkaloid neurotoxicity (2) (3). It has been shown that heterocyclic aromatic amines (which Harmala alkaloids belong to) indeed damage dopaminergic neurons (4). (1): https://hammer.purdue.edu/articles/thesis/Identification_of_Neurotoxic_Targets_of_Diverse_Chemical_Classes_of_Dietary_Neurotoxins_Neurotoxicants/12919016/1 https://hammer.purdue.edu/articles/thesis/Identification_of_... (2): https://onlinelibrary.wiley.com/doi/pdf/10.1002/ijc.20703 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ijc.20703 (3): https://www.sciencedirect.com/science/article/pii/S1570023203008742 https://www.sciencedirect.com/science/article/pii/S157002320... (4): https://academic.oup.com/toxsci/article-abstract/173/1/171/5575765?redirectedFrom=fulltext https://academic.oup.com/toxsci/article-abstract/173/1/171/5...

JamesBarney 6y ago

https://pubmed.ncbi.nlm.nih.gov/20182054/#:~:text=In%20the%20CAIDE%20study%2C%20coffee,decreased%20risk%20of%20dementia%2FAD https://pubmed.ncbi.nlm.nih.gov/20182054/#:~:text=In%20the%2.... this says coffee is associated with a reduced risk of dementia which is pretty much what I've read over and over again

eloff 6y ago
Thank you! I was freaking out about my beloved coffee addiction.
- zikzak 6y ago
  Never blame the coffee.
  - eurasiantiger 6y ago
    That seems like a cognitive bias.
eurasiantiger 6y ago
That study conflates caffeine and coffee from the very first word in the abstract. I wouldn’t trust it at all — it’s like an article about CPUs but the writer doesn’t understand the difference between a processor (called CPU) and the rest of the stuff in the computer case (which, as a whole, is also called CPU).
- heavyset_go 6y ago
  So I read the whole paper, and not just the abstract. The authors do not conflate caffeine and coffee in the meta-analysis, in fact, they cite several studies that document the association between coffee consumption and the reduced risk of cognitive decline.
  - eurasiantiger 6y ago
    Did you check whether those studies do this conflation? Were they epidemiological studies (which cannot prove causality), or double-blind randomized studies (which can)?

ckosidows 6y ago

Just coffee or anything with caffeine? I'm really curious for a source on this, considering how much coffee I drink weekly.

pvarangot 6y ago
If caffeine does it for you and need lots of it, eating just caffeine is probably safer than drinking a lot of coffee. Coffee beans have a lot of of other stuff and it varies from bean to bean and eating a lot of some of that stuff may not be good for your gut/brain/whatever. If you are "addicted" to coffee sometimes you will crave it if you do just caffeine, but this goes away after a while. Be aware also that if you want the antioxidants and other stuff in coffee beans eating just caffeine won't give you that.
- eurasiantiger 6y ago
  There’s really no evidence that antioxidants are categorically good for you. Studies have found that some benefits of exercise are mediated through oxidative stress, and get impaired by antioxidant intake.
eurasiantiger 6y ago
Just coffee. You may have a MAOA VNTR that predisposes you to like coffee.

chubot 6y ago

I agree you have to examine both directions, and a common cause, but the article somewhat addresses that under "chicken or egg?" The headline is misleading. Big idea: a common cause may be jaw development and the resulting lack of breathing (during the day and during sleep) in large parts of the population. Jaw development has a strong claim to be the fundamental, common cause of poor breathing and sleep because it's derived from 2 fundamental differences between humans and animals: agriculture and speech. It's a long chain of causation, and took me awhile to learn about, but it may be what you're looking for. Of course it could also be the case that some people are just staring at screens too much before bed and getting poor sleep. But bad sleep is an epidemic and there is evidence of this all over the world, and going back hundreds of years. The books I reference tell of orthodontists from the 1800's who noticed this problem, etc. Our diets drastically changed, which caused poor jaw development, which causes bad breathing, which causes bad sleep (I learned about this from my dentist). There are many factors that restrict airways, including weight. Remember that the average American male is about 30 pounds heavier in 2020 than in 1960 (and similarly for females). It's hard to imagine that not having an effect of breathing and sleep (and thus dementia). But I think animals can be fat and still have plenty of air for breathing; the same isn't true for humans. Previous comment I wrote on this including recent books (2018-2020): https://news.ycombinator.com/item?id=23435964 https://news.ycombinator.com/item?id=23435964 That article is "fitful nightly sleep linked to chronic inflammation and hardened arteries". That is another correlation, not a causation. So I would suggest that bad sleep, inflammation, hardened arteries, and dementia have a common cause in jaw and airway development. This is a lot harder to see because it took place over 10,000 years and it takes 30-50 years to kill you. You can have bad breathing your whole life but still be functional. It's very related to tooth grinding/bruxism, which is an epidemic as well. Other threads on Hacker News: https://news.ycombinator.com/item?id=24247066 https://news.ycombinator.com/item?id=24247066

TYPE_FASTER 6y ago

> it’s early dementia that causes insomnia > If they drink too much coffee, they might accidentally poison themselves into dementia Oh crap

didibus 6y ago
I wouldn't take anyone making a comment on HN a source of accurate and truthful data. The HN bias can be at play. Which is the bias that we believe and trust a random comment on Hacker News more than a linked research study, or the body of experts around a subject (who don't comment on Hacker News).

jiofih 6y ago

Please don’t upvote this nonsense. Harmala alkaloids are found in tobacco, not coffee.

guerrilla 6y ago
I'm pretty sure harmine and harmaline are found in coffee too. I thought it was common knowledge but all I found were two papers so maybe not. 1. https://www.sciencedirect.com/science/article/abs/pii/S0024320505007514 https://www.sciencedirect.com/science/article/abs/pii/S00243... 2. https://www.sciencedirect.com/science/article/abs/pii/S0308814609013806 https://www.sciencedirect.com/science/article/abs/pii/S03088...
eurasiantiger 6y ago
They are found in both, in high concentrations. Tobacco smoke and coffee are the two most significant sources of Harmala alkaloids in the human diet. (Source: T. Herraiz)
- jiofih 6y ago
  Well, they are found in everything, meat, soy sauce, beer, right? Tobacco is a much more common source. By the logic of your previous argument, eating yakisoba could lead to dementia. Interestingly, your source’s paper on this says that coffee protects against brain disease: > epidemiological studies have consistently shown that coffee drinkers have an apparently lower incidence of Parkinson's disease (PD), suggesting that coffee might somehow act as a purported neuroprotectant https://pubmed.ncbi.nlm.nih.gov/16139309/ https://pubmed.ncbi.nlm.nih.gov/16139309/ Either way, I’m not particularly interested in this subject, the point is that making wild medical claims without sources in an online forum is best avoided.
  - eurasiantiger 6y ago
    They are indeed found in many products, but the key is the exact nature of the specific substances. Do they inhibit MAO-A, MAO-B, or both? Are they irreversible or reversible inhibitors? Do they do other things like cause neurotoxicity? The Harmala family has dozens of compounds, some good for you (for example MAO-B inhibitors indeed prevent PD, because MAO-B inhibitors are used to treat it) and some bad, like some beta-carbolines that are indeed neurotoxic. Again, the total amounts are what matters. It’s much easier to take in too much MAOIs from tobacco and coffee than by eating meat. Something seeming to protect against one specific disorder does not mean that it protects against all diseases.

ineedasername 6y ago

In fairness to the study, it's only claiming an association, not a causal link.

tartoran 6y ago

The OP doesn’t suggest that coffee may cause dementia but was a possibility for sleep deprived and low on dopamine individuals drinking too much coffee to stay functional, exacerbating their sleep deprivation thus rising the prospects of developing dementia.

eurasiantiger 6y ago
No, I was explicitly suggesting that neurotoxic amines in coffee may be building up in some, possibly genetically predisposed heavy coffee drinkers, causing loss of dopaminergic neurons and ultimately dementia, or other neurological disorders. This exact mechanism has been shown to be the cause of a very common neurological disorder called essential tremor. Patients have a genetic predisposition for building up tremor-inducing Harmala alkaloids due to reduced metabolism.