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Espresso coffee mitigates the aggregation of Alzheimer′s associated tau protein (acs.org)
145 points by bookofjoe on Aug 5, 2023 | hide | past | favorite | 107 comments



But see https://pubmed.ncbi.nlm.nih.gov/30322179/, a large meta-analysis that found no association between coffee drinking and Alzheimer's disease:

We performed a dose-response meta-analysis to summarize the prospective data on coffee consumption and associated risk of dementia and Alzheimer's disease. These studies included 7486 dementia cases diagnosed among 328,885 individuals during an average follow-up of 4.9⁻25 years. Meta-analysis of all eight studies indicated no statistically significant association between coffee consumption and the risk of dementia and no deviations from a linear trend (p = 0.08). The relative risk of dementia per 1 cup/day increment of coffee consumption was 1.01 (95% confidence interval (CI) 0.98⁻1.05; p = 0.37). Meta-analysis of five studies that focused on Alzheimer's disease revealed no association between coffee consumption and Alzheimer's disease and no deviations from a linear trend (p = 0.79). The relative risk of Alzheimer's disease per 1 cup/day increment of coffee consumption was 1.01 (95% confidence interval 0.95⁻1.07; p = 0.80). These results do not support an association between coffee consumption and an increased risk of overall dementia or Alzheimer's disease specifically, but further research on the association of coffee consumption with dementia risk is needed.


One talks about "espresso coffee" the other one just says "coffee", could that be significant?


One difference between espresso and coffee made with a paper filter is that there is more cholesterol in espresso. Espresso extracts more from the bean because it is done under pressure, and the paper filter collects some the cholesterol. There is some evidence of a connection between high cholesterol and Alzheimers, so you might expect espresso to be worse, but it doesn't seem that well understood. Maybe the cholesterols in coffee beans act differently.


Are you thinking of cafestol? Cafestol and kahweol are lipophilic terpenes that are normally lost in filtration. They are thought to be cardiotoxins that contribute to the premature deaths of elderly unfiltered coffee drinkers. [1]

[1] https://www.hcplive.com/view/filtered-unfiltered-coffee-cont...


Only animal and animal products have cholesterol. Or did you maybe mean the oils that are extracted? Cholesterol ≠ Lipids.


That's mostly true, but not entirely true.

> There is a widespread belief among the public and even among chemists that plants do not contain cholesterol.

> This error is the result (in part) of the fact that plants generally contain only small quantities of cholesterol and that analytical methods for the detection of cholesterol in this range were not well developed until recently (1).

> Another reason has to do with the legalities of food labeling that allow small quantities of cholesterol in foods to be called zero (2).

> The fact is that cholesterol is widespread in the plant kingdom although other related sterols, such as β-sitosterol (henceforth referred to as sitosterol), generally occur in larger quantities.

> No current biochemistry text that we have examined provides an accurate account of cholesterol in plants.

https://pubs.acs.org/doi/pdf/10.1021/ed082p1791 [2005]

On an unrelated note, just how horrible is this https://sci-hub.se website that gets you most scientific publications for free????


There is a potent cholesterol raising compound, cafestol, in coffee that is removed when the it is filtered with paper.


Some beans are roasted in butter.


Is this a joke?

My roast is done at 650 degrees, butter wouldn’t last 5 seconds.

I’ve seen people add butter to coffee though.


I got downvoted above, but it isn't a joke. Vietnamese coffee beans are often roasted in butter. Robusta beans aren't as common in the US, sadly. After living in Vietnam, it is my preferred bean now. I like the extra bitterness and higher caffeine content of it.

Buy some VN coffee, the beans are often shiny from the oil.

Feel free to upvote this post now that I've shown you something new. =)

https://www.google.com/search?q=butter+roasted+coffee

https://www.thecommonscafe.com/the-ultimate-guide-to-roastin...

https://nguyencoffeesupply.com/blogs/news/vietnamese-coffee-...

https://www.enjoyadaybreak.com/products/traditional-butter-r...


It's not a joke but completely besides the point. Most people aren't drinking butter-roasted coffee. Even if they did, the butter likely isn't adding any actual lipids to the final roast, just slightly altering the internal bean steam pressure, heat, and final water content. Any oils on the exterior would be vaporized at typical roasting temperatures. Also most heavily roasted beans will be shiny with oil within a few days of roasting, regardless of any added butter.


> Most people aren't drinking butter-roasted coffee.

I'm not sure how 'most people' is relevant to the discussion. Fact is that it is one of the largest GDP exports for Vietnam and 5th in the world [0]. Just because you don't drink it, doesn't mean millions of other people aren't drinking it.

"The main destination of Coffee exports from Vietnam are: Germany ($384M), United States ($257M), Italy ($230M), Japan ($186M), and Spain ($150M)."

If I take those beans "shiny with oil" (aka: butter), grind them up and make a cup of coffee with them (I personally go with an aeropress w/ steel mesh), then there is going to be oil (butter) in that coffee. In fact, I can see a slight oil (butter) sheen on the surface of the cup of coffee if I let it sit.

[0] https://oec.world/en/profile/bilateral-product/coffee/report...


I buy French or Italian roast beans which are Arabica and they are also oily. This does not mean they were roasted in butter.


I never suggested that all oily beans are roasted in butter.


Sure, but you're making the assumption that your beans are shiny because of butter, while we know all dark-roasted beans will be similarly shiny regardless. You're not providing any clear evidence that butter-roasted beans retain any oils from butter, and frankly I'm very skeptical of that being the case. Have you ever tried heating butter to 300C in a pan? (Do not actually try this, you will start an oil fire and create lots of smoke)


Since you're so tied up with not believing something:

  > Put beans roasted in butter next to beans not roasted in butter.
Spoiler: they look very different


Definitely not a joke. My friend from Singapore introduced me to butter-roasted beans. He enjoys western style roasts also but apparently craves a regular taste of home as well.

I’m not a fan. Nor was my grinder. Gummy residue.


Not a joke. It's fairly common in South East Asia and even has a name -- White Coffee.


I think you meant it has been shown to raise blood LDL cholesterol. But coffee itself doesn’t have cholesterol.


I wonder if this applies to coffee brewed with a moka pot


Yes. Espresso is extracted differently and lacks paper filtration so is known to be very different from "normal" drip coffee.


Could also just be confounding effects. Espresso machines tend to be expensive, as are cafés where people go to drink espresso. Did the study control for income?


That varies greatly depending on where you are in the world. In most of southern europe "a coffee" is an espresso, and outside of urban and/or tourist centers the normal price is less than 1€.

The study was done in Verona, where I suspect that espresso consumption isn't highly correlated with economic status.


I’m genuinely curious about the economics of the southern European coffee shop. The machines are quite expensive $20,000-$30,000+ (+- $5,000 - $10,000) and so for just 1€ plus they have to eat, potentially pay employees, etc. how viable are these shops?

On the other hand I think that the fact that such cafes exist and seem to work well speaks to walkability and proper transit as a cornerstone of entrepreneurship. In America you basically have to start a Starbucks drive through to get enough volume, or you have to charge $2.65 or something for a single because of a lack of volume.

Proper density (not Manhattan, moreso Amsterdam) and walkability seem to me to drive economic growth and encourage new businesses that don’t need to raise rounds of funding.


That would assume there is a correlation between Alzheimer's and income. In some quick googling of studies, there appears to be. However, with often differing results from US vs. European studies (and studying different things like education instead of income and vice versa, dementia vs. Alzheimers and vice versa, urban vs. macro and vice versa), there are hints that it is an accessibility of diagnosis issue.

We still don't know enough about Alzheimer's to have a definitive bullet list of healthy habits to stave it off. Sleep, exercise, dental health, all have some weak evidence behind it. It seems that Alzheimer's is still a more equal opportunity destroyer than heart disease or many cancers where there are plenty of evidence that you can mitigate risks with lifestyle changes.


In these large trials I assume they are not trying to separate someone who just drinks black coffee from someone who drinks coffee with a lot of sugar (mochas ect…). So the negative affects of daily consumption of sugar and dairy could offset whatever positive affects might have been possible.


Studies on AD and Coffee seem to be all over the place because they are just correlative. People with a genetic disposition to drink coffee (I kid you not) have higher prevalence of AD, people who drink coffee in middle age possibly less prevalence of later AD, so people who were drinking lots of coffee right before developing AD could mean a positive or negative affect.


Yay! Decaf works too:

Three instant coffee extracts (light roast, dark roast, decaffeinated dark roast) and six coffee components [caffeine (1), chlorogenic acid (2), quinic acid (3), caffeic acid (4), quercetin (5), and phenylindane (6)] were investigated for their ability to inhibit the fibrillization of Aβ and tau proteins using thioflavin T (ThT) and thioflavin S (ThS) fluorescence assays, respectively. Inhibition of Aβ and α-synuclein oligomerization was assessed using ELISA assays.

All instant coffee extracts inhibit fibrillization of Aβ and tau, and promote α-synuclein oligomerization at concentrations above 100 μg/mL. Dark roast coffee extracts are more potent inhibitors of Aβ oligomerization (IC50 ca. 10 μg/mL) than light roast coffee extract (IC50 = 40.3 μg/mL), and pure caffeine (1) has no effect on Aβ, tau or α-synuclein aggregation.


But do these things pass through the blood brain barrier?


Wait, instant coffee extract? That is...not espresso

edit: ok, they pulled espresso shots and freeze dried them in the lab (lol) - "The espresso coffee extract was obtained from 15 g of powder using a two-cups coffee machine (Gaggia espresso machine, Gaggia Milano, Italy) for a final volume of 80 mL of beverage. The extraction lasted for 30 s at 80 °C in mQ H2O. The final product was distributed in 15 mL Falcon tubes, freeze-dried, and stored at +4 °C."


80C is really low for pulling shots. Normally it's 90C:

https://bigcupofcoffee.com/espresso-brewing-water-temperatur...


Perhaps they measured the temperature of the espresso shot post extraction, in the cup (or more formal receptacle!), where it would be cooler than the water meeting the ground coffee.

Also, a Gaggia Classic (as an example - they don’t specify which model they use) does not have a PID. Temperature of the espresso leaving the group head drops during the extraction.


While we are criticising, 80ml from 15g of coffee (am I reading the right?) sounds watery.


Let's fix this title: Espresso coffee mitigates the aggregation of Alzheimer′s associated tau protein in cell cultures

Unless you actually have a port in your head to pour coffee into, this is not going to help you with preventing dementia. Also, it's an open question if Tau related are indeed the cause of AZ related dementia.

This is a very irresponsible title for this research.


>Unless you actually have a port in your head to pour coffee into

Is that a thing you can get?


Not for coffee, but for medicines yes.


Love this result, but I’m wary of drawing conclusions from single studies saying caffeinated or alcoholic beverages are good/bad for X health-related issue. Seems like conflicting results show up frequently.

But let’s hope this stands! Back to my coffee…


> alcoholic beverages

Alcoholic beverages are bad at any level, according to all the recent studies. Previous studies that found mild positive effects for small doses were confounded by uncontrolled factors that overwhelmed the (mild) negative effects of alcohol.

For coffee, we at least have pretty good data showing that even large quantities don't have seriously bad effects. So lower quantities are probably at least neutral for health.


The one thing that’s certainly anticdotal, but very easy to see, all the people I’ve ever met that make it to late 90’s or over 100, drink alcohol, albeit sensible amounts


Alcohol is the worst drug and my alcoholic Pts are the sickest people.

We can't treat the pain because the liver is fucked.

Most suffer from EtOH dementia.

Nearly all have pulmonary hypertension to go along with their regular hypertension.

With that goes along CHF and pulmonary emboli and other CVA incidents.

Many suffer agony from pancreatitis, which again we can't treat because of damage to the live.

Alcohol ages every body system rapidly and most of my EtOH Pts have the physiological response of somone 20 years older.

It literally poisons every organ system.


I totally agree with you. However, I rationalize this in my mind (in a very biased manner) with this mental gymnastics.

If there was a paper that very thoroughly proved that caffeine was detrimental, it would rocket up into a high tier journal. So I suspect many people may try to look for negative outcomes but aren't finding them. But also I haven't searched for negative chronic effects of caffeine and only hear of results like this. So maybe I'm totally wrong and there's a conspiracy against publishing results on negative effects.


I mean, at the very least caffeine is habit forming/addictive which is one downside from a physical dependence or financial perspective.


> If there was a paper that very thoroughly proved that caffeine was detrimental, it would rocket up into a high tier journal.

I find this assertion to be farcical. Follow the money - coffee is multibillion dollar market in the US alone. Also it serves the government. Many people in positions of power drink coffee and enjoy it.

Money has power and influences what gets researched.


There are a plethora of studies showing how people who drink the highest amount of caffeine have the lowest incidence of Parkinsons, another protein misfolding disease.


Feel less bad about that 5th coffee now...


It may be that people who get Parkinson's do not crave coffee as much.


Kind of weird that they keep emphasizing "espresso" seeing how an Americano/Lungo/Allongé is basically just an espresso with added water (I might've offended some Italians just now). So why not just focus on the active ingredients instead? Maybe to distinguish from all the capsule coffees most people drink?


They gave pretty decent detail for recreating the sample they analyzed. That's probably better than assuming any sample of coffee would have similar compounds and ratios.


"True" espresso is extracted at around 100PSI of water pressure, so the coffee most people drink, at least in America, may not have the relevant compounds present of they are only extracted at the higher pressure of a true espresso.


adding milk and sugar might change something about the effect of espresso. controlling for that would make the entire study much more complicated.

i'm more surprised about them not calling it simply (black) coffee. possibly because espresso preparation is quite defined versus various methods of how to brew coffee.


Espresso is very different from black filter coffee, because the filters used in other brewing methods do not allow oil and particulate to pass through, so the composition of the drink will be different.


not all brewing methods require filters that provide obstacles for oil and particulate.


What process are you thinking of?

Espresso filter too - the basket has holes small enough to keep the grounds out the cup. The only coffee drink I know that has no filtering at all is Turkish coffee.


If anything wouldn't this argument suggest you should isolate and quantify the active ingredient? Certainly there is more variation between two espressos than, say, two 80 mg caffeine capsules.


i don't think we know much about what the active ingredients are in coffee. we only know caffeine. but i'd bet this is only one among many.


But what is the impact on cognition. Are tau proteins part of the defense or part of the problem?


There have been studies showing that higher coffee consumption correlates to slower cognitive decline. This study only looks at the effects of coffee in vitro.


You are right to call this out. Tau are protective, and if you have the genetics, coffee will raise the risk of AD.

Oxidative stress is the fundamental issue causing Alzheimer's. So there are many causes with one result.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5562667/

"Oxidative stress participates in the development of AD by promoting Aβ deposition, tau hyperphosphorylation, and the subsequent loss of synapses and neurons. The relationship between oxidative stress and AD suggests that oxidative stress is an essential part of the pathological process, and antioxidants may be useful for AD treatment."


> if you have the genetics, coffee will raise the risk of AD.

Citation most definitely needed.


I’ve seen a good amount of research suggesting health benefits of coffee (and tea). I’m not sure if there’s anything definitive, but I periodically look into the topic, as I drink a lot of coffee.

Here are free access patient summaries from the Annals of Internal Medicine on the topic of coffee:

https://www.acpjournals.org/action/doSearch?AllField=coffee&...

And tea:

https://www.acpjournals.org/action/doSearch?AllField=tea&Ser...

And here are free articles about coffee from JAMA journals:

https://jamanetwork.com/searchresults?q=coffee&f_SemanticFil...



Ah yes, now I can justify spending $4000 on an espresso machine


It should be partially compensated by your health insurance.


I imagine “connoisseurs” would try to disagree, but Mr Coffee makes a legitimately decent all-in-one machine for $230 - the One Touch CoffeeHouse. I mostly drink lattes and while they are not as frothy and airy as one from an actual coffee house, for the price and ease-to-make they are astonishingly good.


> I imagine “connoisseurs” would try to disagree, but Mr Coffee makes a legitimately decent all-in-one machine for $230 - the One Touch CoffeeHouse.

The Specialty Coffee Association has a certification program and list of machines that have passed:

* https://sca.coffee/certified-home-brewer

Units by Cuisinart, GE, Oxo, and Zwilling are on the certified list and can be founded listed for US$ 230. One of the main items for certification is getting the water consistently to the correct temperature.

Or you can spend $30 on a dripper and $50 on a (simple on/off) kettle:

* https://cleverbrewing.coffee/products/clever-dripper

With the difference going to a good grinder so you're making coffee with fresh beans.


I briefly looked through the website, does the SCA have a list of "Certified" consumer-level espresso machines specifically? I was disappointed to see that they had certified home brewers for drip coffee and commercial espresso machines that cost $15k, but no espresso machines that I could afford.


> Dozens of machines are submitted for testing every year, but only those that bear the SCA Certified Espresso Machine mark have met our rigorous testing standards:

* https://sca.coffee/sca-certified/espresso-machines

Maybe there is no list of "consumer-level espresso machines" because no machines have met the certification criteria?


Freshly roasted beans are more important for flavor than the preparation method.


And a nice grinder


Burr grinder


Flat burr grinder


Conical please.


Below, what Google's Generative AI [https://www.google.com/search?q=flat+v+conical+burr+coffee+b...] says about this:

Consistency: Flat burrs are known for being more consistent and producing a more balanced extraction

Noisiness: Flat burrs can be noisy and heat up quickly without good ventilation

Price: Conical burr grinders are cheaper than flat burr grinders

Coolness: Conical burr grinders are cooler than flat burr grinders

Gentleness: Conical burrs are gentler on the coffee beans, which can result in a sweeter cup of coffee

Control: Flat burr grinders offer more control, which is good for cafes or commercial uses

Espresso brewing: Conical burr grinders are good for pulling espresso shots

Grounds: Flat burrs often retain more grounds than conical burrs


This is a bit inaccurate, and that is reflected in the top results when you google it.

Conical burrs are not cheaper. You call this when you look at them, the shape is pretty complex. They often don’t have good (low) retention as they are often on massive commercial equipment. They are consistent as all hell.


I just use a mokapot :)


Mokapots are great. We had an espresso machine, but it took more space and cleaning time than a mokapot.


Well, you can't let a cheap espresso machine touch your $25 bag of single-origin coffee beans...


It’s the grinder that gets ya.


PSA: Buy a used Bunn G1 and put SSP burrs in it. I did mine for about $600, which seems steep, but it's way cheaper than comparable grinders and will probably last me decades.


Also check out the G-IOTA, it's sold under several different names but it's the best espresso grinder you can get for the money. It has flat burrs, which are superior to conical burrs.

https://reddit.com/r/espresso/comments/lw8pbo/probarista_gio...


I don't spend that much money on coffee beans but I have the cheapest blade grinder I could buy (one day I will be able to justify replacing it, probably with a Wilfa).

The trick is to shake the grinder up and down while it is cutting. I can get a surprisingly even grind that doesn't get too hot. Good enough for a trouble-free Aeropress plunge, anyway.

These days I am all about the cheap solutions; I'll probably treat myself to a lever-press espresso machine at some point.


An even better solution is just picking up a decent hand grinder [1] especially since you’re doing work anyway.

[1] https://www.hario-usa.com/collections/grinders


If you’re relying on anything other than your own fingertips, it’s time for some grip exercises. Lovingly hand-crafting your beans to fine powder—this is the way.


don't spend more than $600 tbh


Am I only one that feels suspicious that these researcher names are Italian? Next up, Russian study suggests vodka decreases diabetes.


Only espresso? So filter coffee does nothing?


Because the authors are Italian?


Or because the funding came from espresso product manufacturers?


Filter coffee catches oils and particulates, so it's better to try using espresso in case some of those compounds are being removed.


Unless the filtered compounds are causing/preventing another deleterious effect.


Indeed, but if you have to choose a subset amongst the gigantic combinatorial space, the biggest one is probably the first you should choose without some better reason.


Likely cultural factors, but clearly this extends to other methods of processing coffee.


Another recent study found that coffee brewed with a paper filter reduced the chance of type 2 diabetes. That did not happen with espresso or other coffees brewed without paper filters. The explanation offered is that among the coffee compounds, one protects against diabetes and another counteracts the first. A paper filter seems to capture the second compound letting the first through.

Perhaps you need espresso filtered through paper to get both benefits? ;)


Don’t joke about it, it’s a real thing! You can get paper filters in espresso portafilter sizes, and some people use them under the coffee puck and some above (to distribute the water more evenly to try and reduce channeling of water through the grounds).


It's reasonably common for people to use aeropress paper filters in their portafilters. But I think more people who use a screen opt for a metal one.


Not necessarily true, espresso extracts more compounds from the coffee than other brewing methods.


Not necessarily true, filter extracts more caffeine than espresso at the same soluble extraction levels:

https://www.youtube.com/watch?v=etnMr8oUSDo

The truth is there is not enough scientific research to compare all brewing methods. Espresso uses high pressure but very short brew times, but filter uses more water and longer brew times therefore the coffee comes out totally different, and that's before we even talk about different grind sizes and roast levels.


This is nothing like "coffee precents/cures Alzheimers." This is in vitro cells, it's not clear these compounds cross the BBB, and billions of people drink lots of cofffee and tauopathies are on the rise. Tauopathies are diseases of opulence and on ccontrast to what this paper says, there are effective neutrical treatments (Bredeson protocol)


Did a Stanford professor write this?


Espresso? What about filter? Ristretto? French press? Turkish style?


Ristretto uses an espresso machine so I’d expect Simla or behaviour. The others are low pressure, so maybe not?


Any conflicts of interest with coffee companies?


I’d like to know what team will replicate this.


millennials were right actually


Mitigates how much? Please stop sharing news that make vague claims, HN is not Facebook


How could we trust this result and be sure it is not supported by the coffee industry?


Look at the institute, sponsors, the authors funding, etc…? It’s not impossible.




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