The Tempest in a Coffee Pot: Is Coffee Good for You?

Hi! My name is Arne. Having spent years working as a barista I'm now on a mission to bring more good coffee to the people. To that end, my team and I provide you with a broad knowledge base on the subject of coffee.

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This feels like the ideal time to dive back into a question I've wrestled with before: Is coffee healthy or unhealthy? After all, people today obssess as much over the formula for perfect health as they did in the eighties over cute neon tops.

This feels like the ideal time to dive back into a question I’ve wrestled with before: Is coffee healthy or unhealthy? After all, people today obssess as much over the formula for perfect health as they did in the eighties over cute neon tops.

Only now, the Internet is a marvellous megaphone for anyone and everyone to get shouty about their personal truth. In the end, no one is sure what’s right or wrong. It doesn’t help that the thinking on lots of foods and beverages changes on an almost weekly basis. And the pendulum swings on coffee are just as wild as for as bread, avocados and coconut oil.

Is caffeine a blessing or a curse for the body? One camp will tell you that the coffee beans in your cappuccino or pour-over coffee can cause cancer, the other camp glorifies how it will make you live longer and your hair shine.

Arne holds a flat white and looks happy

I’m not a medical doctor so I’m not going to come down hard on either side of the line. Instead, I’d like to give you whistle-stop tour of both the scientific consensus and wild, fringe opinions. On top of that, I plan to home in on the chemical components at the heart of the controversy over coffee beans and caffeine, explaining the sticking points.

Don’t let that give you the impression that this is about to turn into one of those deadly serious articles. In my opinion, everyone is getting far too uptight about this debate, crediting coffee with a “medicinal” value, that it simply doesn’t have.

Part of the problem is that many of the coffee assumptions knocking around unquestioned don’t fit with our ideas about fitness, health and Instagram beauty. It could also be that there are pressure groups with in interest in spreading certain beliefs.

I have no stake in what you decide to do with this information and how it does or doesn’t affect your coffee consumption. What I sincerely hope is that if you get one thing out of this article, it’s this:

The real worry with coffee is that everyone ends up oversimplifying its benefits or risks.

The Fine Line between Instinct, Advice and Fact

Before diving into specific medical indications and coffee’s components, I want to start off by repeating something that I’ve mentioned when talking about the difference between Arabica and Robusta:

Most of the war of words over coffee’s health benefits (or lack thereof) is based on gut feel. Literally.

Some people drink just one espresso and they get an upset stomach. So they blame the coffee. Others can swig back gallons of pour-over coffee and don’t even feel a twinge.

Barista Arne happily prepares pour-over coffee

Bottom line, there is no definitive evidence that any of coffee beans’ key components trigger the symptoms linked to drinking joe – abdominal cramps, high or low blood pressure, all that stuff about dehydration and so on, and so forth. But proof of the brew’s benefits is equally thin on the ground.

The slew of articles and studies conducted on whether coffee is healthy tells you that if we want to get anywhere on this, we need a shift in perspective.

What we have are studies on certain groups of coffee compounds, which suggest a direct link between drinking coffee and good health. A long-term study published in 2018 found that coffee drinkers tend to have a lower mortality rate. Other similar research supports these findings.

Let’s just take a breath before we get overexcited about this. As the same study’s abstract explains, the keyword here is a little one – can. After all, your cup of joe is just one small part of your lifestyle. A relationship between coffee and a longer life, doesn’t mean that coffee is directly responsible for getting to a ripe old age. For now, all we can say is it doesn’t hurt.

A double espresso trickles out of a portafilter machine

If we dig a little deeper, we find that this study only investigated a negative correlation between mortality and coffee consumption. They weren’t even looking for the opposite.

Why I’m being so anal about this? Because I want us all to be a bit more critical of click-baity headlines like “Coffee Drinkers Live Longer” (U.S. News article from 2018). Of course, the same goes for “Caffeine Overdose Killed South Carolina Teen” (NBC News article from 2017).

Read a bit further in the second article and you’ll learn that the 16 year old died after he consumed a large amount of a caffeinated soft drink, a cafe latte and energy drink within two hours. Aha, so it was a cocktail of drinks that added up to huge amount of caffeine.

The bigger coffee gets as a lifestyle topic, the more objective reporting goes out the window. No surprises there.

So, next time coffee makes you nauseous, don’t just write off java wholesale. Look at what factors conspire to make you feel bad.

Let’s now ask ourselves the leading questions about health promises and risks associated with coffee.

Will Coffee Leave you Dehydrated?

This question gives me a real kick. Seriously, how did anyone get such a crazy idea? I mean, you’re chugging back a beverage that’s 98 percent water.

As we all know from experience, pour liquid in one end and it gets peed out the other. That’s how nature works. The question implies that coffee has some kind of “parching effect” and that each sip brings you a step closer to mummification.

Barista Arne pours hot water from two kettles into a cup.

I don’t need a medical degree to tell you that’s a load of bunkum – at least as far as dehydration goes.

Coffee is a diuretic, which means it stimulates the kidneys to produce more urine. Once again, though, what you put in is what you get out. Around 84 percent of the liquid that makes up coffee goes straight through you and is excreted unchanged. What’s left in the body are some of coffee’s macronutrients as well as the caffeine that enters the bloodstream.

On its own, the brew can’t pull more moisture out of cells. So no way you’ll end up a shriveled prune. Medical science refers to this as coffee’s extracellular effect, as opposed to the intracellular effects that would be necessary for dehydration to occur.

According to the experts, you need to chug more than six cups before coffee’s diuretic effects can be felt. Even then, your body develops a tolerance for it. Problem solved. If that weren’t the case, coffee shops would have to have urinals mounted directly onto the counters. Anything less would be a breach of health and safety codes.

Are Europeans to Blame?

So why is it that no sooner have you finished your cup than you’re rushing off to the toilet? Remember I mentioned instincts? Well, add coffee culture – and the European kind in particular – to that.

At coffee shops in Italy and a lot of the rest of Europe, you’ll automatically be served a glass of water with espresso and other coffees. That’s how ingrained the belief in coffee’s “drying” nature is. The thing is your bladder will be sending urgent messages from around 12 ounces (355 milliliters) upwards if you’re a guy and 8.5 ounces (250 milliliters) if you’re a woman.

That glass of water is around 5 ounces (148 milliliters). Add to that another 1–8.5 ounces, depending on the coffee. Boom! If your kidneys are in good working order, you’ll be well and truly feeling the call of Nature. Since a latte macchiato is almost 12 ounces, that alone is enough to give you the urge to go.

Two flat whites with gorgeous latte art stand on a table

When at home, most of us also put away huge cups of coffee as well as water, tea and other thirst-quenching beverages. After all, it’s not coffee you want when your throat is dry. So once again, coffee isn’t the culprit. It’s all the other fluids on the side that are responsible for the frequent toilet breaks. The dehydration myth is so ingrained in our minds that coffee gets the blame.

Turning the Tables: Does Coffee Count towards your Daily Fluid Intake?

Different question, same level of dissension in the ranks. But this time the bottom could fall out of the debate because no one can put an exact figure on how much fluid we need to drink each day. The current scientific consensus pegs it at about 9 to 13 cups.

Then there’s my Coffeeness teammate who can’t function – at least that’s what she says – unless she pours 17 cups down her neck every day. Others in the team are just fine with four cups.

The only thing everyone agrees on is that foodstuffs and liquid refreshments contribute to meeting the body’s requirements. To keep our cells and metabolism ticking along nicely, fresh water and unsweetened herbal teas should, of course, be the lion’s share. Anyone who drinks close to a gallon of soda every day is getting enough fluids but is probably looking at weight and health issues.

Same principle with coffee. Yes, it basically contributes to your daily fluid intake but it’s better to just bracket it off under “luxuries.” Rather than treating your coffee break as some routine necessary to meeting your fluid requirements,  see it as an indulgence. Listen to your body and if you’re thirsty, drink a glass of water.

I found this piece of advice on the German Federal Center for Nutrition’s consumer forum and it really chimed with me. “If someone drinks more than four to five cups of coffee day, it’s unlikely they’re getting enough fluids from other drinks.” Basically, if you consider coffee as a source of fluids, you’re going about things all wrong.

Caffeine – A Bone of Contention

Trying to cover all facets of the debate in detail would be a book-length exercise. One hard fact everyone agrees on is that the caffeine alkaloid is a psychoactive substance.

Also in the hard facts column is European Union Regulation EC 1272/2008, which requires that it must be labeled with an exclamation point, indicating the need for caution. That’s because at certain concentrations, caffeine has distinct toxicological effects. Easy pickings for media outlets into scaremongering. Just see the NBC article above.

Caffeine’s rather intimidating chemical formula is C8H10N4O2. As a stimulant it acts on the nervous system, making your heart beat faster, your pulse race and sometimes causing you to breathe more deeply and increasing the blood flow to the brain, etc.

These effects kick in about 30 minutes after drinking coffee and their intensity obviously varies from person to person. For some, a piece of dark chocolate (yes, there’s caffeine in chocolate) is enough to give them a buzz.

Barista Arne already has quite a caffeine buzz and is preparing more pour-over coffee

Others have built up such a tolerance, they hardly notice anything. For a thorough overview of caffeine’s effect, take a look at this article from Medical News Today.

Notice how just like with other drugs, the body gets used to caffeine, so it takes higher doses to get that kick.

A popular argument revolves around the fact that it supposedly increases blood pressure, making it unsuitable for people who struggle with that. But the current view is caffeine only raises blood pressure minimally. And that’s only until your body gets used to it.

At least that’s what the British Heart Foundation says. And they should know what they’re talking about. In fact, their experts even go so far as giving a thumbs up to five (!) cups a day.

I also like the advice from Harvard Medical School, which tells you to keep an eye on your body. If coffee gives you problems, take a step back. No commandments from on high, no finger wagging, just common sense.

As genuine tinfoil-hat rant, it’s hard to beat an article entitled “Coffee Is Unhealthy” on the German Zentrum der Gesundheit (health center) website. I deliberately don’t want to link to it and have the perfect excuse not to in English.

Although the less Internet savvy consider it highly trustworthy, the site is actually a very dodgy platform for nutritional supplements. It’s the perfect case study on why, when investigating emotive topics like whether coffee is healthy or not, it’s important that you always pay careful attention to the publisher behind the information you read.

Brewing a Bellyache: Chlorogenic acid (and Bitter Compounds) under the Microscope

Let’s back up a bit to the differences between Robusta and Arabica beans. One of those is chlorogenic acid content. Robusta has double what you find in Arabica.

The compound that gets singled out most often when it comes to the gut problems people experience after a cup of joe is caffeic acid ester. At some point, someone discovered that this acid has the potential to trigger stomachaches. And the rest is history. With a name like that, it was easy to lump it with the other bogeyman foods, gluten and sugar.

A side-by-side comparison of an arabica and a robusta bean.

Other studies on mice have drawn very different conclusions – that chlorogenic acid can be beneficial in treating stomach ulcers and cancer cells in mice. In fact, those looking to shed a few pounds take chlorogenic acid capsules or green coffee with a view to getting good news from their bathroom scale. That’s because this acid may boost fat metabolism. Again, in mice.

But the thing for coffee drinkers to remember is that notable concentrations of this acid occur chiefly in raw beans, which break down significantly during roasting. The slower and gentler the roasting process, the more it degrades.

So what we have here is a clear case of the the dose making the poison. The teensy amount of chlorogenic acid in brewed coffee might cause stomach problems. Or it might not.

And if we put this topic under the microscope – and we should – then we also need to look into the bitter substances in coffee. These have been proven to trigger intolerance reactions including, wait for it … stomach pain.

“Histamine intolerance” is the term popular science has latched onto and that is currently grabbing headlines. Already I can see that among kookier circles, panic on par with gluten hysteria lies just over the horizon. Which is why I don’t want to link  to any “scientific” sources. Especially as I haven’t found anything solid so far.

What it boils down to for us is that any number of things can bring on stomach complaints after drinking coffee. Or you can be perfectly fine.

I like this Live Strong article on the links between coffee and bloating, heartburn and abdominal discomfort because it carefully uses terms such as “may,” “can” and “suggests.”

Is Coffee the Secret to a Slimmer, Healthier and More Alluring You?

Pick your research papers right and you’ll find all kinds of indications that coffee increases fat burning and therefore helps you lose weight. Since caffeine can ramp up your metabolism, that would seem to hold water.

Not so fast. Again, we need to read more closely: One of these studies examines the relationship between caffeine and successful weight loss maintenance. Yes, maintenance. Not actually getting you into your thin jeans in the first place.

Dig a little deeper and other sources suggest that you’d have would have to drink in the region of 12 cups a day and have never touched coffee before in order to notice any change. And as soon as you build up a tolerance, it’s all over. Unsurprisingly, that kind of potential is fodder for articles like “Coffee Is a Calorie Killer,” which appeared in a German Women’s Weekly.

The Halo Effect

The way I see it, this is where we come up against the cognitive bias known as the halo effect. Basically, a positive experience with one facet of a product leads us to believe that it will also deliver in other areas. Brewed coffee has virtually no calories, perks us up and gives us a brief buzz. Zero calories and an injection of zing? Well, coffee simply must be a great slimming product, you tell yourself.

Which explains how die-hard health fanatics can tell you with a straight face that three triple mocaccino lattes with caramel syrup on one day is totally fine. It’s coffee, ergo healthy.

A zombie figurine emerges from among coffee beans

Turning a blind eye (hello halo effect) to the fact that a zero-calorie drink quickly turns into a 400-calorie bomb when you add fat, sugar and other chemicals. It’s also why big coffee shop chains bury their nutritional information in practically illegible tables. Yes, we’re looking at you, Starbucks.

With that in mind, I’d like to briefly touch on bulletproof coffee again. Until recently, this combination of coffee, coconut oil and butter was the health fad of the moment. The word “slimming” was bandied about. A lot.

All the ingredients – butter, coconut oil and pour-over coffee – to make bulletproof coffee are laid out on a table

Then suddenly it drops off the radar. Why? For starters, because our ideas about carbohydrates and its “challenger” fat are only starting to shift. But also because the concoction simply lacked marketable mass appeal. Finally, this bit of health nuttiness encourages us to view coffee in the wrong light:

Why are we so determined that coffee should have any specific effect at all? Coffee simply is. It’s a stimulant, a philosophy, a piece of culture and an art form. Any physical benefits are just the cherry on top.

Expanding Horizons: What Exactly Defines “Healthy Coffee”?

Enough with the medical minutiae. Time to shift gears and give you a different perspective. The World Health Organisation (WHO) defines health as “a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.”

I think this is really important – especially in connection with coffee. The value of this luxury commodity for human health are hotly debated, while social aspects tend to fall by the wayside.

But they do matter. After all, we import coffee from the poorest countries in the world, where locals labor hard to grow, harvest and process it.

What we end up paying for the product isn’t always a true reflection of product’s value. For more detail on this, you can read my article about what coffee farmers earn.

My point is, of course, that a pound of supermarket coffee for about $4 is certainly not “healthy,” for the simple reason that it’s exploitative and perpetuates social inequality.

Barista Arne makes pour-over coffee from arabica and robusta beans

As a result of this social injustice, disease and mortality rates are higher, while living and educational standards are lower in coffee-producing countries. Basically life is not good and conditions are anything but health.

Is Coffee Healthy? I Say Yes!

My great-grandmother firmly believed that coffee sends you to sleep. She ran a home for the elderly and would give residents coffee when they couldn’t sleep.

Then they were promptly tucked up in bed and usually soon fell asleep. Today, we know drinking coffee increases blood supply to the area in the brain that controls sleep. But you have to hit the sack pronto for a coffee nap, otherwise the stimulating effects gain the upper hand.

Before I found a biological explanation for my great-grandmother’s story, I thought it sounded about as much like scientific fact as my belief that coffee makes life richer and better.

Because coffee’s effects vary from one person to the next and so many factors are at play, anecdotal evidence is the only kind we have to go on. Even so, it’s safe to say that all the scare stories about coffee are largely untrue. Bottom line:

Coffee used to have a really bum rap.

But I have to add:

Coffee is not healthy.

Let’s get this straight. Coffee is not medicine. If it were, your beans would come with a package insert. By the same token, if it were really such a risk to your health, the bag would have warning messages and symbols printed all over it.

So if coffee helps you literally start your day full of beans or unwind in the afternoon, that’s got to count as something positive. No further research required.

Barista Arne sniffs at a cup of espresso

But if every sip leaves you feeling more rotten, start by checking up how much coffee you’re knocking back. Next, take a closer look at the quality of the beans, the brewing method and the specifics of the process. Only after all that should you consider that your body is chemically at odds with joe.

Of course, I can’t just gloss over the fact that high-risk groups, such as pregnant women, breastfeeding mothers and people with very high blood pressure absolutely must watch their coffee consumption and keep it to a minimum. That’s just common sense.

And that’s where I’d like to leave things in the debate on whether coffee is healthy.

What are your thoughts? I look forward to your comments!

Updated: 10. April 2024
Your coffee expert
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Arne Preuss

Hi! My name is Arne. Having spent years working as a barista I'm now on a mission to bring more good coffee to the people. To that end, my team and I provide you with a broad knowledge base on the subject of coffee.

More about Arne Preuss

Hi! My name is Arne. Having spent years working as a barista I'm now on a mission to bring more good coffee to the people. To that end, my team and I provide you with a broad knowledge base on the subject of coffee.

More about Arne Preuss

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