Those following my “What about…?” series know I welcome your inquiries about foods, drinks and supplements.
I’ll address these items one-by-one, examining whether and how they fit into the basic primal parameters for healthy eating and living.
This week’s question comes from a Facebook fan, who asks a very, very important question:
What about coffee?
Yes. Yes. I hear you. This query is near and dear to my heart. It’s also a big one warranting a two-part answer.
But, before I get to that answer, a disclaimer: I am a full-on coffee addict.
More precisely, I’m an espresso addict.
More precise yet, I’m addicted to bulletproof coffee containing 2 long espresso shots, a tablespoon of grass-fed butter or 2 tablespoons of full-fat organic coconut cream, and a teaspoon of coconut oil or high-potency MCT oil.
Still unfamiliar with bulletproof coffee? It’s a darling of paleo-primal circles and a delicious hack when engaging in intermittent fasting (which, for me, takes the form of not eating during the interval between late dinner and early lunch).
So. Now that you’re clear where I’m coming from…what about coffee?
Let’s start with the good news.
As you’ve probably noticed, caffeine is a stimulant. And coffee containing it stimulates the central nervous system, offering a temporary boost to energy levels, cognitive function, concentration and memory.
In the short term, it may even elevate happiness by increasing serotonin levels. Makes me happy—that’s for sure.
Beyond that feel-good-and-focus magic, coffee is full of health-supporting antioxidants and phytochemicals.
Studies also suggest correlations between coffee drinking and reduced risk of disease and early death. (I don’t know about you, but so long as I get my morning fix, my husband and siamese cats have reduced risk of disease and early death too.)
But seriously, research indicates coffee consumption may lower risk of cardiovascular disease, metabolic diseases (such as diabetes) and cognitive decline (including dementia and Alzheimer’s). Some findings even suggest anti-cancer effects.
But, as you might expect, the full answer’s not so easy.
Today, I’ll look at some general stuff. Then, in Part 2, I’ll focus on individual-specific considerations.
This next bit may get a bit dense, so hold on tight. Worse comes to worse, just skip to the final few paragraphs. Ready? Let’s go.
Okay, so we know coffee has an impact on energy, focus and mood…but what’s really behind that?
The picture is more complex than “just” affecting the central nervous system. What we’re really talking about here is the neuro-endocrine-immune system—essentially, the complex of structures, functions and interrelationships that make up our nervous system, endocrine (hormonal) system and immune system.
We often discuss these systems as though they are separate. In brief: they are not. Indeed, this overarching “neuro-endocrine-immune system” is also inseparable from our larger body-mind. (Though we’ll be teasing apart “sub-systems” here, for the sake of explanation and discussion.)
In truth, we don’t fully understand how coffee affects our body-mind ecology. We just know it’s complicated and coffee’s sphere of influence extends beyond the nervous system.
This uncertainty is partly due to the nature of epidemiological studies.
These studies look for correlations between various factors and states of health or disease. Problem is, methodological limitations and myriad variables often confuse things.
For an overview on navigating scientific literature, see Chris Kresser’s post here. Meanwhile, as one example, consider that coffee drinking is correlated with many other diet and lifestyle patterns—and that people who abstain from coffee are likely making other health-conscious choices. So when a study compares coffee drinkers and non-coffee drinkers, many other variables are missed.
As another example, consider that not all coffee is equal. Its constituents and qualities vary greatly depending on the type of bean as well as growing, roasting and preparation methods. Is it freshly roasted? Instant? Organic? (Seeing as coffee is one of the crops most heavily sprayed with pesticides, this would seem an important factor.)
So what’s being studied, exactly? Who’s consuming it? For how long, how often and in what quantities?
Given these types of considerations, it’s no surprise that not all studies line up. Research on caffeine’s impact on fat metabolism, for instance, is mixed.
Okay, okay, so approach scientific findings with caution. But what do we know about coffee’s effects on the body-mind?
Well, let’s start with the “neuro” part of that neuro-endocrine-immune system.
No shocker that the caffeine in coffee has psychoactive properties. It’s part of a group of naturally occurring chemical compounds called methylxanthines. These compounds boost energy levels, cognitive function, alertness and feelings of well-being.
Drinking caffeinated coffee on a regular basis increases receptors for several key neurotransmitters (you can think of these as nervous-system messengers).
Specifically, it increases receptors for: acetylcholine (involved in contraction of skeletal muscles and excitation/inhibition of internal organs); gamma-aminobutyric acid, or GABA (inhibits neuronal activity to induce relaxation and sleep); and serotonin (involved in regulation of mood, behavior, appetite, sleep, memory, learning, temperature, muscle contraction, and functioning of the cardiovascular and endocrine systems).
This increase in receptors may contribute to the boost in energy and mood brought on by a cup of joe. Caffeine also inhibits release of GABA (the big neuronal inhibitor), making us feel more alert.
What’s more, regular caffeine consumption enhances the sensitivity of serotonin receptors. In other words, receptors for serotonin are more responsive.
To top it off, caffeine has been shown to increase serotonin levels in the brain’s limbic system, which plays a big role in regulating emotional responses and mood.
This increase in serotonin levels and serotonin receptors is partly why we see withdrawal symptoms—particularly anxiousness or irritability—when quitting coffee.
The picture gets messier, however, when we consider that chronic caffeine consumption also reduces “cofactors” needed for making those very neurotransmitters.
Coffee drinking can reduce the amount of B vitamins in circulation, for instance, potentially interfering with GABA, serotonin and dopamine synthesis. It also inhibits absorption of iron, required for synthesis of dopamine and serotonin.
So, that gives us some idea of the “neuro” side of things.
Even without understanding all the details, suffice to say that regular consumption of caffeinated coffee impacts our neuro-ecology in big ways.
In particular, it messes with the manufacture and functioning of important neurotransmitters.
Moving on, what about the endocrine (hormonal) part of that neuro-endocrine-immune system?
In the dubious domain of “mass-media medicine,” there’s a common assertion that coffee and caffeine contribute to “adrenal fatigue.” This isn’t totally wrong. But it isn’t totally right either.
In truth, we don’t fully understand how coffee drinking affects the adrenals—or the endocrine system more generally.
One thing we do know is that caffeine affects the hypothalamic-pituitary-adrenal (HPA) axis. This axis—linking the hypothalamus and pituitary glands in the brain and the adrenal glands on top of the kidneys—plays a staring role in our hormonal stress response.
Caffeine increases two hormones secreted by the adrenal glands in response to stress: cortisol and epinephrine (also known as adrenaline).
Coffee drinking can thus induce signs and symptoms of an acute stress response, including elevated heart rate, respiration rate and blood pressure.
In the short term, when prompted by an appropriate stressor, this “acute stress” response is natural and healthy. Over the long term, when stress becomes chronic, it takes a tremendous toll on the entire body-mind. One result is what many call “adrenal fatigue” (though, in actuality, the entire HPA-axis is involved).
Is coffee drinking part of this problem?
Could be. But so could insufficient sleep, incessant multi-tasking, sustained mental-emotional stress, over-work and over-exercise.
Any of these ring true and you’re also downing cup after cup? Not going to help things…and will likely make them worse.
There are other hormonal considerations too, though, once again, these aren’t fully understood.
When the liver metabolizes caffeine, for example, it employs an enzyme system used in estrogen metabolism. Caffeine competes for that enzyme system’s attention, potentially slowing other metabolic processes.
In the case of estrogen, this may be why caffeine metabolism tends to be slower in women on birth control pills or hormonal replacement therapy.
Again, the picture is complicated and far from clear. But coffee drinking for sure provokes a stress response and likely affects other hormonal processes as well.
Alright, so we’ve found our way to the “immune” part of our neuro-endocrine-immune system.
Like the nervous and endocrine systems, the immune system is complex and intricately connected with all parts of our body-mind. And, yet again, coffee drinking’s effects on this system are not fully understood.
Findings do suggest that caffeine shifts system dominance toward the “adaptive,” or “acquired,” immune system. This part of the immune system produces antibodies when we’re exposed to specific pathogens. In case of repeat exposure, the antibodies recognize those pathogens and launch an attack. We can think of this mechanism as our immune system’s memory.
Meanwhile, our “innate” immune system protects us in a generic, immediate way—as a first line of defence against external pathogens.
By shifting toward adaptive-system dominance (relative to our innate immune system), regular caffeine intake may, under certain circumstances, have a therapeutic effect.
It may be helpful, for instance, in autoimmune conditions characterized by innate-system dominance (because we’re shifting towards the other system).
Meanwhile, for other people, this caffeine-induced shift may promote too much adaptive-system activity. This may take the form of inflammation and hypersensitivity reactions (manifesting as allergies, for example).
If someone has an autoimmune condition characterized by adaptive-system dominance, caffeine may make it worse (because we’re shifting even further towards an already-dominant system).
As a side note here, many people sensitive to gluten have cross-sensitivity to other proteins, including that found in coffee.
Coffee’s not alone in this. Many people with gluten sensitivities or intolerance also react to proteins in other foods, including non-gluten grains (e.g., amaranth, quinoa, rice), corn, potato, soy, dairy and chocolate.
But coffee’s an especially common culprit (and the protein involved is in caffeinated coffee as well as decaf).
Whew. That’s a lot. I know.
Plus, remember how I said we were separating the “neuro,” “endocrine” and “immune” bits for the sake of explanation and discussion? And that they are really part of an intricately interconnected system, which, in turn, is intricately interconnected with our whole body-mind?
As you might imagine, these partial understandings of what coffee drinking does to each part of that system are but a small, curtained window into an even more complex story.
Another big piece, for instance, is coffee’s impact on metabolism. And once again, the picture isn’t totally clear.
I’ve already noted that research on caffeine’s impact on fat metabolism is mixed.
Beyond that, the caffeine in coffee has been shown to irritate the gut in some cases—particularly if someone’s already suffering from gut problems and inflammation.
Similar to a Standard American Diet full of grains and sugars, chronic coffee drinking may also increase insulin resistance. When this happens, the body releases more and more insulin in an effort to get glucose out of circulation and into cells (which insulin is meant to do—but here it’s flailing because the cells aren’t suitably receptive).
High insulin levels, in turn, lead to high levels of “interleukin-6.” And chronically elevated interleukin-6 can lead to that adaptive-immune-system dominance we mentioned above (along with associated inflammation and hypersensitivity reactions). Interleukin-6 also causes release of cortisol…which further elevates glucose…and further contributes to the insulin-resistance cycle.
Yeah, yeah, yeah. So what’s so bad about high blood sugar and insulin resistance? These days, they’re as American as apple pie (a pre-packaged one with a wheat crust and lots of high-frutose corn syrup in the filling).
Honestly, that’s a whole post (or two or three) in itself. But think inflammation (in its myriad forms—some of which may surprise you) and disruption of our body-mind system as a whole—including mood and cognition.
Okay, that’s an awful lot. Sorry. But really, if you want, you can just ignore it.
Because the bigger problem with all those general considerations—and with study findings—is that they are, by their very nature, not individual specific.
They give us some solid things to think about…but don’t address individual-specific tolerances and sensitivities (which, by their nature, are highly variable, complex and all-important).
So—sorry once again—but my real answer to “What about coffee?” is coming soon, in Part 2.
Until then, enjoy your cup of joe—and perhaps experiment with bulletproof.
But, not so fast. There’s a catch.
As you savor each sip, here’s your homework:
1. Keep in mind some of these general considerations—coffee drinking’s potential benefits…as well as its complex, not-so-perfect effects on the body-mind.
2. Get curious about your coffee-drinking habits and experience. How much are you drinking? When are you drinking it? How does it make you feel in body-mind? Immediately? In a few hours? That night? The next day? Do some objective reporting—track all the details you can without getting lost in opinion. See what you notice.