Here are more fascinating facts about caffeine and cancer.
Caffeine affects the immune system via at least two opposing mechanisms.
Mechanism 1: A2A receptor antagonism (immunostimulatory)
Tumors and damaged tissues release adenosine, which engages the A2A receptor on immune cells and signals them to stand down. Caffeine antagonizes (i.e., blocks) this receptor.
Mechanism 2: Raising intracellular cAMP (immunosuppressive)
Caffeine also inhibits phosphodiesterase, the enzyme that hydrolyzes (i.e., breaks down) cAMP. cAMP accumulates inside immune cells, which acts as a "calm down" signal.
Note: both mechanisms are dose-dependent. At dietary caffeine levels, A2A antagonism likely dominates, whereas PDE inhibition is weak and mainly relevant at higher concentrations. However, the net immune effect in the tumor microenvironment remains unproven.
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If you would like to learn more, I can outline a framework for technical folks to ease in and become more informed on cancer. Gaps abound. The more people who understand cancer, the faster we get to cures. Moreover, personalized cancer treatment is the obvious future. Knowledge acquired now may pay off later (but hopefully not needed).
On second thought, I will publish something regardless of interest.
It will be an "Cancer for Engineers" framework, delivered via free, open-source Custom GPTs and Claude Skills. (Gemini gems are less reliable in our experience.)
The goal: to ease engineers into cancer via AI personalized introductory curriculums with varying time commitments to enable deeper independent investigation or fast exits if interest wanes: 4 hours, 8 hours, 12 hours.
Basically 1-3 hours per week for a month.
The reason I think some engineers may find cancer interesting, aside from the societal impact:
The human body is like a complex operating system. Cancer is a severe runtime error. Tracing root causes -- like genetic mutations, signaling errors, or immune evasion -- has many parallels to diagnosing system failures.
BTW if anyone from Kaggle/GDM is reading this, we are having issues submitting a benchmark paper for NeurIPS based on the Kaggle Benchmark.
Google models seem to get a different scheduling priority, ironically, enough and take >20 hours to complete a benchmark task that other models like Opus 4.6 finish in <1 hour -- same code path, same task. Would love help if possible since the abstract deadline is Monday (It's last minute because we didn't originally plan to submit this, but someone suggested it.)
For people questioning why to involve GPT and AI assistants:
GPT and AI assistants cannot be fully trusted, but they can personalize learning.
The chief challenge for the framework/handbook will be resolving how to personalize guidance into cancer research while grounding knowledge in trustworthy sources.
For instance, the framework will anchor abstract, dry biological concepts in personally meaningful tracks. Imagine someone you care about is battling lung cancer — the framework may orient learning around the molecular drivers and signaling pathways at play, or perhaps how to explore the treatment landscape while respecting established practices. If you're fortunate enough to not know someone affected by cancer, GPT can help find a personal angle.
The sheer depth of information is staggering. People devote entire careers to niche specialities, and these experts still don't know everything in their niche because our understanding of human biology and disease is constantly evolving. Adapting depth should also depend on the individual and can only be achieved via AI. Static curriculums do not maximize learning in 2026.
I will aim to put together a Cancer 101 for engineers, not sure how to share. Maybe I'll post here or will post to our biomedical GitHub so it can evolve over time?
Great question. The bar for proof in biomedicine is naturally high. I only shared facts because so much is unknown.
If you can find a lab exploring the question, maybe you can support them by helping to raise money for experiments.
As a fun intellectual exercise, dive into the topic and challenge yourself to think about what kind of experiments could shed more light on the subject.
Hey, man, drink what you want. It doesn't change my life in any way, shape, or form. But I have to ask, have you seen the image describing where decaf coffee comes from?
I should hope you're not being serious! In case anyone thinks this is real, decaf is not made from the dirt. It's beans that have gone through one of a few different processes. Swiss water method is what I prefer due to the low chemical processing.
Perhaps try roasted fig coffee substitute? It's definitely not coffee but has enough of the same roasty flavor notes to be passable. With milk and sugar, I probably wouldn't notice it wasn't coffee if I wasn't paying attention.
Depends on your definition of healthy and sweet. ‘Healthy’ is vague and fairly subjective. Plenty of coffee substitutes exist, such as roasted chicory-barley mixes that taste decent and provide you with some fiber. Is it healthy?
My question is whether espresso-method coffee has all the same properties. The study itself clearly states "brewed coffee" and they brew the crap out of it ("extraction in boiling water for 8–10 min"), I can't take brewed coffee on the regular b/c it upsets my stomach.
Yes, I know the four main methods of decaffeination. The haters have gone down this road with me many times. Why can't people just let me drink my decaf? It's like they can't enjoy their caffeine unless everybody does. It's weirdly pushy.
I don't think GP was criticizing you for liking decaf. Just pointing out that the decaf process may have affects on the beneficial compounds that aren't caffeine.
I didn't even know there were 4 methods - supposedly Swiss Water Process is the best in terms of not affecting the flavor or exposing you to exotic solvents, is one of the four superior to SWP?
My initial charitable reading -- as someone who sometimes dabbles in decaf -- is that decaffeination has the bad side effect of stripping flavors, and likely many of the other biologically active chemicals. I can see from their further posts that they were more interested in unscientific fear mongering instead.
That said, I do think there is some truth that decaf is lacking (including via supercritical CO2) and I wonder how long until we could have a product like genetically engineered coffee plants that produce everything except caffeine. I'd like that, though I can immediately see an issue with growing a plant without its natural pesticide.
> likely many of the other biologically active chemicals.
Do you reckon taking green coffee beans and roasting them til they’re brown right through has any detrimental effect on the biological compounds in the beans?
There is nothing objectively wrong with drinking something you like the taste of, however, when it is coffee specifically, I believe, the utility of it is the caffeine it contains; that, and the culture around coffee-drinking makes me feel the way I described. Notice the "in my humble opinion" at the end of my message.
Exactly — I am taking caffeine pills, and when I confessed this to a normie coffee drinker, I was called an addict, even though not only is the dose mere 100 grams, half of that of a Tim Hortons medium black, the pills also have L-Theanine in them, which is supposed to reduce jitteriness or something.
By "All you haters that give me grief for drinking my daily cup of decaf can shut up now", you are implying that decaf has the same health benefits of real coffee. That's not proven. And if you weren't meaning to imply that, there was no point to that reply.
Right? All high quality coffee makers use a proper method so there is absolutely zero downside in decaf. Just make sure to check which method they use (all big ones state it on their website or else)
I love coffee, so this is a nice read. Couple years ago I switched to french press, fresh beans (grind on demand) & no milk or sugar - okay, a dash of full cream milk sometimes. Has to be strong - you can't drink weak coffee like that!
Not everything is dopamine. Maybe nitpicky on my end but it gets tiresome when everyone is just like dopamine this, dopamine that, when no one really understands neurotransmitters.
Haha, I viewed a video recently (in French) that said « dopamine is right-wing ».
It was ironic but interesting : dopamine is viewed as THE neurotransmitter of motivation while in fact it’s only one part of the mechanism. But it’s the part everyone is bragging about because it supports the idea that you can control your dopamine levels and be responsible of your own motivation.
The whole point of the argument was that your serotonin and noradrenaline levels were as much as important if not more, and, fat chance, you cannot buy serotonin or noradrenaline supplements. You have to be in mentally in a good place to get those right and that’s not something you have that much control over. Especially your noradrenaline levels are strongly tied to the quality of your environment and that’s why you should politically fight for a better life environment.
Are you saying that non-Parkinson's patients are taking L-DOPA as a supplement? If so, that's nuts.
Also dopamine is a precursor to noradrenaline, and serotonin levels are affected by numerous drugs, the most popular of which are antidepressants. That "supplements" for these neurotransmitters has more to do with how effectively they cross the blood-brain barrier and how they might disrupt the gut, since many chemicals in the brain do double duty through functions in both brain and gut.
For the health benefits, without some of the downsides, I believe it is preferable to drink coffee when you are not tired. This way you don't get a crash later, because there is no adenosine build-up (the 'tiredness' signaling molecule that caffeine blocks). I believe this also helps to prevent addiction, because there is also no up-regulation of adenosine receptors.
This works great if you drink coffee for the taste, rather than as a way to stay awake (which works in a pinch but is counter-productive over the long term).
I generally always sleep well, but enjoy a nice big cup of coffee in the morning. If I'm really sleep deprived, I switch to black tea. Seems odd because you'd think less caffeine would be worse, but the tea is easier on the stomach and somehow "evens out" the sleep deprivation better.
Not exactly, the article says that the effects aren't linked to caffeine, not that decaf has been shown to have the positive effects or still contain the necessary chemicals.
I love coffee. It's good for you, it smells and tastes so good. It wakes you up, and prevents sleepiness after meals. Its stimulant nature is a plus, but not necessarily the main thing.
I would be very cautious about any conclusions regarding its health benefits or detriments. Nutrition research is notoriously difficult to replicate or show causal links in humans engaging with the real world.
Texas A&M also has a coffee research center dedicated to promoting and protecting global coffee trade and consumption so… yeah.
Unfortunately the most flavorful methods (espresso, french press, moka) also raise your cholesterol. So sadly, no, coffee is not universally "good for you". Filtered coffee methods are though, as the filter absorbs the oils.
Always so cute how fellow coffee lovers will loudly boast the health benefits of coffee, but when you add an asterisk they will see it as a personal attack and respond strongly :)
Coffee is not what defines your identity. It's fine to admit it isn't perfect.
My point is not that unfiltered coffee is good, I’m just saying that northern italians who eat dessert for breakfast, cook everything in lard, drink unfiltered coffee and even (gasp) sometimes smoke cigarettes are significantly healthier than Americans on every metric.
Not saying those things are necessarily good for you, I’m just saying we don’t seem to understand this stuff very well
Probably because they don't consume gobs of HFCS and ultra-processed foods, don't take the car for every single thing[0], and have obesity/overweight rates that are 20-40% lower. A healthier work-life balance and concomitant lower cortisol and blood pressure also helps a lot.
If you compare Italians and Greeks to, say, Swedes and Dutchies, you'd get a much different picture.
[0] not entirely Americans their personal fault, their urban design isn't for walking around
If something has several clear positive effects, and a possible small, arguably irrelevant, negative effect, most people will agree that yes, it's good for you.
It's like trying to argue that running may have a negative effect on some people's meniscus under some specific circumstances. That doesn't negate the generalization "running is good for you".
But filtered coffee is the most flavorful! No other method extracts the subtle nuances as well!
P.s. I know it's subjective, just cringe on this claim of "the most flavorful" starting with espresso. :)
Yep, every method brings out a different nuance of coffee flavor, and any true coffee snob will likely own half a dozen or more items for brewing coffee.
Sorry brother but the worry around cholesterol - especially in the context of the US - is not stemming from people drinking too much coffee. If you have high cholesterol there are 15 other things you should probably be cutting down on. This is similar to people who tell people to watch the sugar content in their fruit intake. No ones getting obese off fruit, the benefits outweigh the negatives tenfold.
While what you say is true, people carrying extra weight are often prediabetic and should be watching sugar/carb intake in the morning when blood glucose levels are already rising without food. That also happens to be one of the most popular times of day to consume fruit, which is why choosing a fruit with a lower glycemic index (or load) at breakfast is importance.
FYI since many people don't know: Decaf isn't zero, it can still be several percentage points. In the US decaf is supposed to be under 3% of regular coffee but it's not commonly tested or enforced, so many types of decaf can be quite a bit higher. Several big cups of decaf can approach the caffeine content of one regular cup.
> Several big cups of decaf can approach the caffeine content of one regular cup
Do you have a source for this? Because it doesn't sound right to me. And also, I live in a coffee producing company, work adjacent to the coffee industry, and had a long conversation with someone planning to set up a business exporting green beans to the US, and their beans were getting tested to an extreme degree and being rejected for a few ppm over on certain things.
I have heard the 3% rule but fyi it's 1% in the EU and since there's actually not that many large scale decaffeination factories in the world, as far as I know they all target the EU level.
If you buy small batch, large batch, or somewhere in between it's probably been processed in one of these few large factories.
And that article links back to this UFL press release. I've clicked every link I can find and there's not an actual, published study to be found anywhere:
I am definitely going to do this as I age, I just don't need the stimulant effects as much anymore. That said, the ritual of getting coffee and sipping on something warm in the morning is really important to starting my day right.
Sadly, I can't. I tried all the decaf beans in my area and even some fancy online roastery specialized only in decaf beans, and they all tasted like ass, compared to their caffeinated cousins. So much money wasted trying to find good tasting decaf beans.
Not sure what the decaffeination process does, but it definitely does not preserve the taste of the "untouched" beans. Are my tastebuds too sensitive?
I was never a coffee drinker, but I became interested because what was said in Arnold Schwarzenegger‘s newsletter. ( There is a ton of medical research covered in there. )
I didn’t dig in too deeply, but started drinking a morning cup of sugar free double mocha cappuccino, to help my workouts.
If I’m fooling myself, don’t tell me. I like the cappuccino.
I did use pure nicotine and it was very bad for my health, probably due to high dosage, but still.
I've used heavy stimulants, benzos, opioids, dissociatives without an issue, but nicotine is in a class of its own in terms of how insidiously addictive it is.
But just from a health point of view: extreme arm and hand joint issues, forearm vascular issues that made my hands numb at night, palpitations/arrithmia like I was about to die when I used nicotine before sleep and I was drifting to sleep -- it really felt like I was about to die, like my heart was mangled up.
A lot of people consume nicotine. It has been isolated and used in products for a long time. There's no clear link to cancer, but it could impact cardiovascular health (like all stimulants seem to).
Some research indicates that nicotine can influence how existing cancer behaves and spreads, so that's worth considering.
He was suggesting— jokingly— that maybe coffee cancels out the deleterious effects of smoking, because indeed coffee + a cigar or pipe is truly an excellent experience.
I quit smoking a long time ago but if there's one thing I'm missing / craving is a hot cup of coffee with two cigarettes on an empty stomach during cold winter mornings... Fuuuuck.
Caffeine affects the immune system via at least two opposing mechanisms.
Mechanism 1: A2A receptor antagonism (immunostimulatory) Tumors and damaged tissues release adenosine, which engages the A2A receptor on immune cells and signals them to stand down. Caffeine antagonizes (i.e., blocks) this receptor.
Mechanism 2: Raising intracellular cAMP (immunosuppressive) Caffeine also inhibits phosphodiesterase, the enzyme that hydrolyzes (i.e., breaks down) cAMP. cAMP accumulates inside immune cells, which acts as a "calm down" signal.
Note: both mechanisms are dose-dependent. At dietary caffeine levels, A2A antagonism likely dominates, whereas PDE inhibition is weak and mainly relevant at higher concentrations. However, the net immune effect in the tumor microenvironment remains unproven.
---
If you would like to learn more, I can outline a framework for technical folks to ease in and become more informed on cancer. Gaps abound. The more people who understand cancer, the faster we get to cures. Moreover, personalized cancer treatment is the obvious future. Knowledge acquired now may pay off later (but hopefully not needed).