Is coffee good for you? What are its main chemical components? What is caffeine, and how does it affect the body? Why do some people feel its effects more than others? When shouldn't you drink coffee? And finally — is decaf any healthier than caffeinated?
Yes, that's a whole slew of questions. 😉
Yet it really boils down to just one…
Do you drink coffee?
Then this post is for you!
I grew up around my Tata's Arabic coffee — simmered, black, spiced with cardamom, and poured into teensy white ceramic cups. Now, years later, I've decided it's high time to investigate the brew that captivates so many!
Robusta Vs. Arabica
First, let's take a peek at the world behind your beloved cup of joe.
Coffee is brewed from the roasted seeds (or “beans”) of the Coffea tree fruit. Although there are over 120 species in the Coffea genus, only 2 species are commercially grown around the globe: Coffea canephora (often called “robusta” coffee) and C. arabica. (The World Atlas of Coffee, page 12.)
While robusta trees are hardier, disease-resistant, and account for a third of global production, arabica yields the higher quality coffee and accounts for the remaining two-thirds. Arabica is also smaller, more delicate, and rather finicky to grow. When connoisseurs describe its aroma, they talk of “flowers, fruit, honey, chocolate, caramel, or toasted bread” (source). Sounds great to me!
Robusta coffee is native to humid West Africa, while arabica comes from the highlands of Ethiopia and Sudan (On Food and Cooking, page 442).
Interestingly, there are many different varieties of arabica trees. And yet, because coffee is traded based on where it was grown, these varieties may skate by relatively unknown to consumers. (The World Atlas of Coffee, page 22.)
Once ripe, the coffee fruit — very similar in appearance to a cranberry — is harvested, processed, and dried. Then, the new beans are roasted, ground, and brewed.
What's In Your Cup Of Coffee?
What are the main chemical components of coffee?
Well, there's caffeine — but it's only 1 out of 2,000 other known substances found in coffee — including proteins, carbohydrates, lipids, amino acids, aroma compounds, and melanoidins, which give roasted coffee beans their brown color (source).
Remember that the coffee bean is the seed of the coffee tree! It contains all of the plant cell material needed for the tree to reproduce. While roasting transforms some of that material, it still forms the basis of the compounds today identified in coffee. (Source.)
Although this list isn't exhaustive, let's detail a few of those compounds just for fun!
#1 — Caffeine of course tops our list. We'll discuss caffeine in more detail later, but in case you're wondering, arabica beans contain less caffeine than their robusta counterparts — less than 1.5% by weight of the dry bean compared to 2.5% (On Food and Cooking, page 442).
#2 — Chlorogenic acids are powerful antioxidants found in coffee. Some sources even say they rival the great antioxidants themselves: Vitamins E and C! And yet, others say they lose this ability once metabolized by the body. (Source, source, and source.)
#3 — Diterpenes such as cafestol and kahweol are fat-soluble compounds linked to higher cholesterol levels. Interestingly, by using a paper or cotton filter such as with the glass Chemex coffee maker (see picture below), you can filter them mostly out! (Source and source.)
Coffee In Your Gut
We already know how important it is to maintain the integrity of our intestinal health. What role does coffee play?
Well, it strongly stimulates production of the hormone gastrin in the gut, which then encourages production of hydrochloric acid (source, source, and source). Hydrochloric acid is actually a natural part of the digestive process. But in high enough concentrations, and especially if the gut's protective mucosal lining is already damaged, the acidity can irritate the gut lining and prevent healing.
Thus, those suffering from bowel diseases often can't tolerate coffee (source).
However, non-heme iron isn't the most readily absorbed form of iron anyway (see this post for more details!) and any calcium deficiency related to coffee may be due in part to the fact that coffee drinkers tend to not drink as much dietary calcium (such as found in milk) in the first place (source).
So, eat liver and drink milk if you are able (or find other dietary sources of iron and calcium) — but not with or right after drinking coffee!
Finally, it takes about 45 minutes for the body to absorb 99% of caffeine into the bloodstream — longer if digested with food (source). Pretty fast!
After it does this, caffeine travels throughout the body to various tissues, eventually making its way to the liver for metabolism. Its half-life — the time it takes for the amount of caffeine in the body to decrease by 1/2 — is typically around 2-1/2 to 4-1/2 hours. (Source, source, and source.)
The Truth About Caffeine: What Is It?
What is caffeine, and how does it affect the body?
As it turns out, caffeine is the most widely consumed psychoactive drug in the world. In other words, it affects the mind (among other things).
And as we've already mentioned, the body absorbs caffeine quickly and almost completely from the digestive tract. Caffeine also acts as a stimulant to the central nervous system — the part of the nervous system that includes the brain and spinal cord. (Source and source.)
Because it is fat-soluble, caffeine easily crosses from the bloodstream into the brain via the blood-brain barrier (source). This leads us to our next subject of inquiry…
Caffeine In Your Brain
Let's talk about neurotransmitters and chemical receptors.
Neurons are nerve cells that send and receive information through chemical or electrical signals, such as a neurotransmitter. The neurotransmitter leaps from one neuron to a chemical receptor on another neuron. Think of the receptor as a lock, and the neurotransmitter as the key that unlocks it. (Source.)
Adenosine — one such neurotransmitter — protects against energy depletion. It typically promotes sleepiness by binding to special adenosine receptors in the brain. Once the body has been awake for a prolonged period of time, adenosine accumulates, binds to its receptors, and neuronal activity decreases… Voila, sleep!
And, quick side note, adenosine also promotes vasodilation (widening of blood vessels) when needed.
Caffeine, on the other hand, is called a competitive agonist. It blocks the action of adenosine by binding to — but not activating — adenosine receptors. This not only prevents sleepiness, but also releases other neurotransmitters, resulting in a burst of renewed energy. (Source.)
With prolonged caffeine consumption, neurons compensate by not only sending out more adenosine, but by creating extra, more sensitive adenosine receptors too. Even if some are blocked by caffeine, all won't be! This is called up-regulation.
Once an individual abruptly stops their caffeine intake again, they may go through a withdrawal period. With adenosine once more free to bind to its receptors, and a higher number of receptors available, subsequent headaches, fatigue, flushing, and anxiety can occur. (Source.)
Caffeine may also contribute to chronic daily headaches (source).
Is caffeine's effect on the nervous system all bad? Maybe not! As it turns out, high caffeine intake throughout an individual's life may protect from cognitive degeneration in later years (source and source).
Why Does Caffeine Affect Some More Than Others?
Much of it depends on how fast your liver metabolizes caffeine. If faster, thanks to your genes and their effect on your enzymes, caffeine won't affect you as much. If you metabolize it more slowly — so it sticks around in your body longer before being excreted — you will be much more sensitive to caffeine's effects. (Source and source.)
Other factors affecting your sensitivity include the amount ingested, time of consumption, frequency, degree of absorption, whether you're pregnant or not, etc (source).
So, How Much Caffeine Per Day Should You Have?
The Mayo Clinic recommends up to 400 mg caffeine/day for adults, with anything over 500 mg defined as heavy usage (source).
But what does 400 mg caffeine look like in a cup? Although caffeine content in coffee varies dramatically, this study suggests there's an average of 204 mg caffeine in a 12-ounce serving of coffee.
Another study gives a range from 72 mg (flavored mix coffee) to 754 mg (specialty espresso) caffeine per 12-ounce serving. Yes, a huge difference! But who drinks 12 ounces of espresso at a time, anyway?! 😉
For comparison, a 1-ounce shot of specialty espresso contains 62 mg caffeine (source).
In my opinion, even 12 ounces of coffee every day is too much — and that falls well under the recommended daily limit of caffeine. Why do I think that? Because if I were to drink 12 ounces of coffee every day, my body would never have a chance to function apart from its influence.
So, how much daily caffeine should you have? Make an informed decision based on the facts and the overall health of your body. And, keep in mind that tea, energy drinks, soda, and chocolate all have caffeine, too (source)!
When You Shouldn't Drink Coffee
Based on my research, coffee doesn't mix with certain health conditions. So, you shouldn't drink coffee…
#1 — If you have gut issues. As mentioned above, coffee in the gut means lots of hydrochloric acid, and hydrochloric acid in a compromised gut means pain. Give yourself time to heal.
#2 — If you have HPA axis dysfunction (also known as adrenal fatigue). Studies show that caffeine increases levels of stress hormones (such as cortisol and adrenaline) produced by the adrenal glands (source). So if your adrenals are already over-burdened or out of whack, coffee makes it worse.
(Learn more about HPA axis dysfunction here.)
#3 — If you have a thyroid condition. According to animal studies, caffeine affects both the thyroid-stimulating hormone (TSH) and thyroid hormones (source). While this has not been replicated in human studies yet, it's cause enough for concern, especially since high caffeine usage “may blunt pituitary TSH response” and thus the thyroid's ability to function (source).
#4 — If you need coffee to function properly. Although coffee may not cause any problems in the short-term, coffee in the long run does induce an unnatural state of activity in the body. So, if you can't do without your daily caffeine fix, perhaps it's time to address any underlying reasons why your body can't cope by itself anymore. Are you getting enough sleep? How is your diet? Are you deficient in any important vitamins or minerals?
If you'd like to dive into the world of yummy coffee alternatives, check out this decaf bulletproof coffee, this bulletproof coffee-inspired tea, and 12 Natural Energy-Boosting Drinks — No Caffeine Allowed!. Or, make your own DIY herbal coffee!
The Scoop On Decaf
What about decaf — is it any better than drinking caffeinated coffee?
First, let's clarify that “decaf” simply means that at least 97% of the caffeine in coffee has been removed, according to USDA standards. So, most likely, there's still some caffeine left (source).
Decaffeination is actually a challenging process because caffeine alone must be removed from the green coffee beans. None of us want weak decaf where coffee's delicious flavor and aroma compounds are removed, too!
It is possible to decaffeinate coffee while also preserving flavor and aroma. There are 3 major ways: chemical solvents (either methylene chloride or ethyl acetate), the carbon dioxide method, and Swiss Water Process.
Do the words “chemical solvents” ring any alarm bells? They do for me, too! It's said that any residual solvent left in decaffeinated beans (around 1 part per million) likely evaporates off due to the subsequent high roasting and brewing temperatures. However, why take that chance when there are non-chemical alternatives?
The carbon dioxide method uses “supercritical” carbon dioxide to draw out caffeine from the beans at extremely high pressures. Decaf coffee from the grocery stores usually has been decaffeinated via this method.
Finally, the Swiss Water Process of decaffeination uses activated charcoal in a chemical-free process that results in 99.9% caffeine-free coffee. Pretty neat — and their facility is even certified organic and kosher!
This fascinating video explains how their process works. The whole method takes about 10 hours, start to finish.
So, look for the Swiss Water Process label or logo the next time you buy decaf!
Surprisingly, research on the pros and cons of coffee is very much ongoing. Much of it is still inconclusive. And so, as with many foods, coffee seems to be a mixed basket.
For all of its purported benefits, is there a better way to achieve them? Or, might we avoid its risks by practicing a healthier lifestyle in the first place?
Those with deep-seated gut issues, adrenal fatigue, or thyroid conditions may not tolerate coffee at all.
For those of us who can indulge now and then, perhaps the answer is moderation — and plenty of nutritious, real foods to balance out the occasional cup (source). A fair trade, shade-grown, organic cup, of course. 😉
In case you're wondering, my husband and I love to hand-grind locally-roasted beans in our portable coffee mill (pictured at top), then brew the grounds either in our glass Chemex with an organic cotton filter, or in our stainless steel French press. Either way, lovely and delicious!
Do you drink coffee? What about decaf? Did you know the truth about caffeine? How does it affect you?
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