Having multiple cups of coffee is just as good – maybe better – than having several servings of vegetables.
Another family dinner. Uncle Uno (hey, we’re Finnish; we’ve got funny names) is sitting across the table from me as the various dishes are passed around. Uno partakes liberally of the meat and carb dishes, but passes on the salad. He actually swears at the green beans as they glide by. He practically threatens to take up arms against the rutabaga casserole.
Yep, even rutabaga, a Finnish staple!
Uno clearly doesn’t like fruits or vegetables (except for boiled potatoes), yet, surprisingly, he appears healthy. He’s lean, energetic, and he doesn’t have any chronic diseases or ailments, and I can’t remember him ever being sick.
But what Uno does partake of, liberally, is coffee. You rarely see him without a cup in his hand. Most of us think it’s a form of ballast and if you took the coffee cup away from him, he’d float back to Finland, shaking his fist at all of us as he drifted away.
You probably have an Uno or two or three in your life.
That predilection may well be what’s kept Uno and others like him healthy. He doesn’t know it, but coffee is as nutritionally valuable as practically any vegetable, something that should be given the same respect as kale, chard, lima beans, broccoli, or any of the other traditional powerhouse vegetables nutritionists (including me) are always attempting to shove down your throat.
Coffee is probably the main supplier of polyphenols in the American diet, and probably the rest of the world’s diets, too. Accordingly, it’s one of the healthiest things you can pour down your gullet.
Its benefits are diverse, but as is the case with most healthful things, there are conditions attached. Let’s look at some of those benefits first before we start looking at any possible negative attributes (and how to remedy them).
You’ve probably all heard that drinking coffee can reduce “all-cause mortality,” but what the hell does that even mean? Surely coffee can’t protect you from getting hit by a runaway ten-wheeler, your last conscious moments spent watching a pair of speeding chrome mudflap girls flutter away from your flattened body. Neither can coffee keep you from falling into an open manhole cover, can it?
Well, epidemiologically speaking, it can.
All-cause mortality means just that, death from any cause. Granted, coffee doesn’t protect you from accidents, but when you factor in its protective effects from the big killers like heart disease, diabetes, and cancer, it does indeed lower overall death numbers, accidents be damned.
You’re also likely aware of new research that suggests drinking coffee was associated with significant reductions in cardiovascular disease (Chieng et al, 2022). Researchers identified three coffee subtypes – decaffeinated, ground, and instant – and divided drinkers into 0 cups per day, less than 1, 1 cup, 2-3, 4-5, and over 5 cups a day.
They then tracked the health of 449,563 participants for over 12 years. All coffee subtypes were associated with a reduction in “incident CVD” (cardiovascular disease), but the lowest risk was seen in the 2-3 cup a day group who drank decaf, followed closely by ground coffee drinkers and then, a half-step behind, instant. Even so, the differences among the three in cardiovascular protection were negligible.
So, coffee protects and maybe even buttresses up the heart. Check. What else you got?
A large umbrella review of meta-analyses (Poole, et al, 2017), one backed up by EPIC (European Prospective Investigation into Cancer and Nutrition Study), found that coffee (both caffeinated and decaf) was associated was lower incidences of type 2 diabetes, kidney stones, Parkinson’s disease, gout, liver fibrosis, non-alcoholic fatty liver disease, liver cirrhosis, liver cancer, and chronic liver disease.
And that’s just the stuff they happened to look at. Coffee’s complete list of health benefits might be even more far-ranging than currently realized.
Coffee has sometimes gotten a bad rap for its caffeine content, but most of caffeine’s ill effects are either transient or mitigated by coffee’s overall health benefits. Caffeine does appear to raise blood pressure in some people, but habitual users develop a tolerance to that side effect. It can of course also contribute to insomnia, but that too may fade with habitual use.
Paying attention to caffeine’s half-life of 2.5 to 4.5 hours, depending on the individual, might also help with the insomnia problem. In other words, switch to decaf 5 to 10 hours before bedtime if it keeps you up.
High caffeine intake can also stimulate urine production slightly, but no detrimental effects on hydration status have been found with long-term, moderate (400 mg. a day) intake. That dry mouth you feel after drinking coffee? It’s because of the tannins in the coffee, not because caffeine is a potent diuretic that’ll cause you to dehydrate, convert to dust, and blow away like Melisandre in GOT.
Some people also mutter about caffeine negatively affecting insulin sensitivity, but that’s only in the short term. Consumption of up to 4 to 5 cups per day for 6 months has failed to affect insulin sensitivity (Alperet, et al, 2020).
Caffeine has also been credited with some of coffee’s beneficial effects. It’s true that caffeine can improve lung function in adults, possibly reduce the risk of liver fibrosis or cirrhosis, lower the risk of Parkinson’s, improve thermogenesis (which leads to burning of fat) and, of course, improve mental and physical performance.
However, it’s more likely that caffeine is a contributory factor to coffee’s halo of health, rather than a primary factor. As evidence, many studies show decaffeinated coffee to have virtually the same healing powers as the caffeinated stuff.
So, what is it that makes coffee a health elixir?
The standard go-to answer, one that any soccer mom, Starbuck’s barista, or mob boss will give you is that it’s “full of antioxidants” and that “it’s a powerful anti-inflammatory.” Both those things are true. Coffee is full of antioxidants and it does have some anti-inflammatory action, but so does any food stuff that comes from a plant.
More importantly, both animal and human studies show that the coffee is only a weak antioxidant and the concentrations of coffee constituents reached in plasma are too low for efficient free radical scavenging.
The same goes for its alleged anti-inflammatory effects. Randomized, controlled studies that compared water intake to coffee intake over several weeks found small and inconsistent variations in inflammatory markers in coffee drinkers (Kempf, 2010).
So, forget that simplistic stuff for now. The truth is that coffee, as proposed by researchers Kolb, Kempf, and Martin (2020), “probably employs the same pathway as recently suggested for ‘healthy’ vegetables or fruits, i.e., the induction of health-promoting adaptive responses of cells in the body.”
There it is. When infused through hot water and ingested, the ground-up coffee bean, although not technically a fruit or vegetable (more accurately, it’s a seed), conveys many of the same health benefits, through the same mechanisms, as any nutritionally valued vegetable.
Coffee, as is evident to anyone with an IQ that has a fightin’ chance of hitting three digits, is entirely of plant origin. As such, it makes sense that ingesting it would convey similar benefits as described for hundreds of other plant foods.
And like its plant cousins, coffee contains hundreds of phytochemicals, most of them polyphenols (214 mg. of total polyphenols per 100 ml.), but as Kolb, Kempf, and Martin point out, there’s one big difference that sets coffee apart:
"In habitual coffee drinkers, coffee is the primary dietary source of phytochemicals like phenolic acids and polyphenols even in comparison to green tea in Japan. At the level of populations, coffee provides around 40% of polyphenols and around 70% of phenolic acids consumed, followed by tea as the second major source.
“We therefore propose that coffee employs similar molecular pathways for improving health as described for other plant foods such as broccoli, beetroot, pomegranate, curcumin, cocoa, and many others.”
That means that for people like my Uncle Uno who can’t fathom why a benevolent God would create foodstuffs like vegetables, drinking coffee might be the one thing that’s keeping them from meeting the angels sooner than they planned.
Little do they know that drinking coffee spurs the expression of several genes that conjure up enzymes like superoxide dismutase, catalase, glutathione peroxidase, and glutamine-cysteine ligase; enzymes that are involved in DNA repair, free radical scavenging, and anti-inflammatory actions.
Likewise, several enzymes that have a “xenobiotic detoxifying action” (deep cleaning the body of pollution, pesticides, food additive, carcinogens, drugs, etc.) are created, a whole list of big Scrabble-score words like nicotinamide adenine dinucleotide phosphate, quinone oxidoreductase-1, uridine 5’-diphospho- glucuronosyltransferase, and heme oxygenase-1.
At the same time, coffee decreases gene expression of pro-inflammatory compounds like tumor necrosis factor-alpha or NLRP3 inflammasome.
In this electron microscope world, coffee acts like Dr. Strange, conjuring up a whole seemingly mystical array of wondrous compounds that protect the body.
A bit of clarification here for those who look for the grain of error in things instead of the grain of truth: While I said coffee’s powers didn’t come from its anti-oxidative or anti-inflammatory compounds, that’s different from coffee spurring the expression of certain genes that resulted in heavy-duty anti-oxidative and anti-inflammatory effects. That gene-induced effect is much more powerful than the effect exhibited by the phytochemicals themselves.
Oh, there’s something else, too. All the aforementioned effects of coffee require biochemical modification. No problem, but unaltered, non-biochemically modified coffee straight from the pot, as it surges into the gut, also has a prebiotic effect; it nurtures the growth of Bifidobacterium, the most dominant species in a healthy human gut.
Studies show that furthering the population of this bacterium has been used to treat a diverse range of human conditions ranging from IBS and constipation to liver problems, stomach problems, aging in general, and even cancer.
By now, you’re thinking that this coffee stuff sounds pretty good but before you get yerself some of it, we need to discuss its drawbacks and see if there’s anything we can do about them.
Coffee, unfortunately, raises LDL cholesterol a bit. The main culprits are a class of phytochemicals known as diterpenes. The two head-honcho diterpenes that seem to instigate most of the trouble are known as cafestol and kahweol.
It’s somewhat odd that these two diterpenes would be troublemakers. On their own, they’re known to be both anti-microbial and anti-inflammatory, but throw them in with all the other compounds in coffee and they act in unexpected ways. Think of them as straight-A college students who joined a fraternity and suddenly went Animal House.
The good news? Plain old paper coffee filters remove the diterpines from coffee as it brews. By how much? A Swedish study found that drinking coffee made with paper filters lowered the risk of dying from cardiovascular disease by an additional 15% over non-filtered coffee (Mucci, Wilson, 2008).
So yeah, use a paper filter to brew your coffee (not one of those gold filters that only trap the grounds). That’s one troublemaker down.
That leaves us with the chemical known as acrylamide, which is an allegedly carcinogenic chemical. It forms in plant-based foods from a natural reaction between sugars and the amino acid asparagine when the foods are exposed to high-temperature cooking, e.g., frying, roasting, or baking.
Oddly enough, the U.S. government doesn’t recognize acrylamide as a carcinogen when it’s in food. However, it is classified as a “potential occupational carcinogen” by The National Institute for Occupational Safety and Health (NIOSH).
So, eat all you want, but for heaven’s sake don’t sit naked in a mound of it. Go figure.
Regardless, plenty of animal studies have indeed found it to be carcinogenic when it’s ingested. You know that lovely brown tint on perfectly cooked French fries? It’s indicative of the presence of acrylamide. The aromatic brown crust on freshly baked bread? Also indicative of acrylamide.
The same thing happens to coffee when it’s roasted. Using common sense, you’d think that dark roasts would contain more acrylamide, but you’d be wrong. Acrylamide forms during the early roasting process, but it starts to break down as the coffee continues to roast.
Even in worst case scenarios, the acrylamide in coffee is fairly negligible, but when you drink several cups every day…
Luckily, there are things we can do to mitigate our exposure. First, many of the studies implicating coffee in adding to human being’s collective acrylamide load were done in Europe, where everybody drinks espresso-type coffees and nobody’s ever seen a drip coffee maker outside of dubbed, streaming episodes of The Office.
Espresso has more acrylamide-laden coffee crud, aka sediment, floating in it than drip coffee. Although we don’t have any confirmation of this, it’s reasonable to suspect that filtered coffee, as it does with diterpines, might filter out some of the acrylamide.
Regardless, here are some simple avoid-acrylamide rules.
- Use darker roasts.
- Employ a drip coffee maker.
- Instant coffee, regardless of roast, contains more acrylamides than brewed, so try to curtail your intake of it.
- While it’s not universally agreed upon by coffee researchers, it appears that the actual type of beans (e.g., Robusta compared to Arabica) makes little difference in acrylamide levels, so follow your coffee bliss and drink whatever coffee species you want.
Regardless of all this brouhaha over acrylamide, we have to put things in perspective. An average brewed cup of coffee might have 7 parts per billion (ppb) of acrylamide, but a serving of Pringles BBQ flavor chips has 2,510 ppb. McDonald’s French fries have 497 ppb. A bowl of Cheerios has 266.
And who knows, maybe all the beneficial phytochemicals in a cup of coffee would negate any theoretical ill effects from the acrylamides in it?
If recent stats can be believed, over 75 million Americans have K-Cup machines or K-Cup knockoffs in their homes and they use them multiple times a day. Americans ignored their high cost, their environmental destructiveness, and their scorched metal taste and filled their cupboards with the tiny pods.
K-Cup drinkers might have a problem, though, and it’s far worse that just having the palates of goats. It seems that people who drink K-Cups are ingesting significant amounts of potentially health-damaging estrogenic chemicals.
When these plastics are manufactured, monomers, polymers, and additives such as plasticizers, many of which have estrogenic activity, are polymerized to form a base resin, which is often then mixed with other resins to improve the qualities of the plastic.
Unfortunately, these estrogenic chemicals can leach from the completed pod because polymerization wasn’t complete, or because the additives weren’t completely bound to the polymer.
But forget all that manufacturing jargon and minutiae. When the U of C researchers tested six brands of capsule coffee, they found all of them to have estrogenic activity.
Granted, the potency of this estrogenic activity was six or seven orders of magnitude weaker than actual E2 (estradiol). To give you a frame of reference, a typical dosage of E2 used for purposes of hormone replacement therapy in women is 2 mg. daily, and that’s approximately 100 to 1,000 times stronger than the total estradiol content from a cup of pod coffee.
However, when compared to other estroenic consumables like soy-based foods or bottled water, the researchers noted that the “estrogenic potential of capsule coffee was relatively high.”
And there’s something else to consider. Most people don’t have an occasional cup of pod coffee now and then. Many can easily down four to six cups of this plasticized, estrogenic brew every day, and it’s not a reach to assume that long-term exposure to even minute levels of estrogenic chemicals can have physiological repercussions.
I got rid of my K-Cup machine a long time ago. My advice is for you to do the same.
I’ve thrown a lot at you. I could have thrown a lot more at you, but even strong coffee might not keep your attention. As such, it’s only fair that I synopsize what I think are the most important take-home points:
- Coffee should be viewed as a healthy vegetable food.
- Anywhere from 1 to 5 cups a day has been shown to reduce all-cause mortality, but 2-3 cups a day seems to be the sweet spot.
- When possible, use paper filters to brew your coffee so that you trap potentially harmful diterpines and maybe even acrylamides.
- Pick darker roasts as increased roasting helps incinerate some of the acrylamides.
- Take the brand-new K-Cup machine you received as a wedding gift and drop-kick it into a trash can.
- Chieng D et al. The impact of coffee subtypes on incident cardiovascular disease, arrhythmias, and mortality: long-term outcomes form the UK Biobank. Eur J Prev Cardiol. 2022 Sep 27;zwac189. PubMed.
- Kiyama R. Estrogenic Activity of Coffee Constituents. Nutrients. 2019 Jun;11(6):1401. PMC.
- Kolb H et al. Health Effects of Coffee: Mechanism Unraveled? Nutrients. 2020 Jun 20;12(6):1842. PubMed.
- Sakaki JR et al. Estrogenic activity of capsule coffee using the VM7Luc4E2 assay. Curr Res Toxicol. 2021;2:210-216.
- van Dam RM et al. Coffee, Caffeine, and Health. N Engl J Med. 2020 Jul 23;383(4):369-378. PubMed.