I like to think of caffeine as everyone’s favourite 8 carbon compound.
But that’s because I’m a weird science guy and its chemical structure is: C8H10N4O2
In reality, caffeine is often referred to as the most widely consumed Central Nervous System stimulant (CNS) globally – but you probably know it as that fun thing in your coffee that wakes you up and even might help you poop.
Just to clarify that comment on the CNS, caffeine’s primary way of working in the human body is to reversibly and temporarily block what are known as adenosine receptors (which exist, you guessed it, in the CNS).
Since adenosine receptors usually are responsible for slowing down the body, when they are temporarily blocked by caffeine we get that stimulant effect that we’ve come to expect.
So there you go!
One fun caffeine fact down, and yet despite being among the most heavily used and well-studied compounds ever, there are quite a few misunderstandings about caffeine among the general public.
I’m going to sort five of those out right here in today’s post.
Hope you are as excited as I am, let’s get right to it!
Myth 1- Caffeine Interferes With Your Iron Absorption
You didn’t see this one coming did you?
While it’s true that coffee and tea particularly are known to inhibit the absorption of plant-based iron sources (non-heme iron such as in nuts, seeds, lentils, tofu and whole grains) it’s actually not the caffeine that is responsible for this effect.
It is instead the significant quantity of antioxidant compounds (known as polyphenols) that inhibit non-heme iron absorption.
Coffee and tea, by the way, contain more antioxidants then most foods – they are much more then just caffeine.
This may be why, for example, the American Institute Of Cancer Research has identified regular consumption as potentially protective against liver cancer.
The good news? Vitamin C ( oranges, kiwis, strawberries, mango etc) improves iron absorption more than polyphenols inhibit it, so adding one of these to your iron-rich meal will do a world of good.
Myth 2 – Caffeinated Beverages Don’t Count To Your Daily Fluid Totals
If I had to pick the most common caffeine-related nutrition inquiry I receive from clients, this right here would be it.
Do caffeinated beverages dehydrate me?
It’s a fair question because, for a very long time, this was something of a consensus among the general public and yet recent studies and commentary from researchers have begun to refute these claims.
Case in point, a 2014 study out of the PLoS One journal determined that moderate caffeine intake ( 4 cups of coffee per day) was not found to have any dehydrating effect on men who were usual coffee drinkers.
One must keep in mind that when consuming caffeinated beverages, whether coffee, tea or energy drinks, that you are doing so in the context of consuming a significant amount of fluid too.
Now there is of course a recommended range within which to keep your caffeine intake in to avoid any negative side effects, and that’s exactly what we will discuss next.
Myth 3 – We All Drink Too Much Caffeine
But do we really?
Health Canada has identified 400 mg of caffeine per day, for the average adult, as a moderate daily intake that is not associated with any adverse effects.
Less than 1 in 4 Canadian adults exceed this number.
While caffeine metabolism is somewhat individualized, this number represents a very useful target for most people.
Keep in mind that a cup of caffeinated tea has 40mg of caffeine, 250 ml energy drink has 80mg whereas coffee, depending on the source can range between 80-120 mg per cup.
As some basic math will show you, that’s quite a bit of wiggle room to stay within that 400mg figure.
Now there are also individuals, like myself, who may be tempted to go over that number (a pair of daily cold brews will do that to a man).
If you find yourself in this position, try to keep that last caffeine hit at least 6 hours before bed to minimize any potential negative effects on sleep.
But hey, no matter what you’ve heard, caffeine isn’t all negative when it comes to your health.
Let’s end today’ article with an understanding of why.
Myth 4 – Caffeine Has No Health Benefits Beyond Waking You Up
So coffee is, by a significant margin, the most common form of consumed caffeine in North America.
I mentioned earlier in today’s piece its potential role in liver cancer risk reduction, and a 2017 British Medical Journal Paper had this to say specifically about coffee:
“ Coffee consumption seems generally safe within usual levels of intake, with summary estimates indicating largest risk reduction for various health outcomes at three to four cups a day, and more likely to benefit health than harm.”
Long-term moderate coffee intake as also been associated with a reduction in type 2 diabetes risk.
Of course given the fact that coffee is such a uniquely rich source of antioxidants and the primary source of caffeine intake in our population it can be hard to separate the effects of caffeine from the other compounds found in coffee and tea as well.
Caffeine, as a whole, however, has generated a good deal of interest in potentially playing a role in reducing the risk of neurological conditions such as dementia and Alzheimer’s which tend to hit later in life.
I encourage you to take a look at this 2010 paper entitled “Caffeine as a protective factor in dementia and Alzheimer’s disease” to learn more.
Final Thoughts
Well, there you have it folks.
I hope you enjoyed today’s article which was brought to you in collaboration with my morning cold brew and the Canadian Beverage Association.
I’m hoping you learned a few new fun facts about caffeine which will give you peace of mind about enjoying your favourite products and beverages in a moderate fashion going forward.
Until next time,
Andy De Santis RD MPH
