For those of you that know me, you’re more than aware for my love of coffee and how in the past few months I’ve significantly cut down from c. 5 cups a day to just one in the am! That being said, I have replaced a couple with a decaf version - I see it as a transition period, with still getting my beloved coffee taste minus the adverse effects. Having grown up in a Blue Zone, coffee is big part of the diet - no debate, and even centenarians in these regions have reported drinking 2-3 cups of coffee per day.1
However, like every single thing in medical research and especially when it comes to nutrition and food, views can be dichotomous - to say the least. When I talk about coffee I either mean plain black coffee (espresso, french press, moka pot etc) possibly with some milk, no sugar or sweeteners, or any instagrammable dessert coffees for the obvious reasons. Caffeine is the active stimulant in coffee (black tea too) and it affects your body in many different ways, of course this depends on (i) the amount consumed and (ii) how your body reacts and metabolises caffeine.
The obvious is the alertness that you get post a cup of coffee, biologically speaking what happens is the the caffeine blocks the action of adenosine (a brain chemical that’s involved in sleep) and hence why you feel less tired and more alert. It increases energy levels and helps with focus, outside of the adenosine-blocking, adrenaline (the fight or flight hormone) is also released. Another hormone that may also be produced is cortisol (the stress hormone) upon consumption, this usually happens when you have a coffee in the morning on a empty stomach. Naturally cortisol levels are the highest when you wake up in the morning so this is fuelling that even further. So, what I also changed, aside of reducing consumption, was to drink my coffee once I have finished having my breakfast. In this way (i) less cortisol is produced and spiked, (ii) caffeine absorption into blood was slower compared to when not so I don’t get a huge spike in energy followed by a crash, and (iii) I mitigate the acidic effect of it. Continuous consumption throughout the day is the reason it affects sleep and can cause insomnia, cortisol aside, it is due to caffeine’s half life being around 5-6 hrs.
Another big thing about caffeine is its diuretic effect, meaning it actually makes you dehydrated which also affects energy and focus but you don’t fully realise as you’re consuming a liquid. Decaf coffee, actually does not have this effect as the caffeine amount in it is negligible and that’s what causes the dehydration.
Physiologically, short term your heart rate and blood pressure is increased, these are not permanent, but also the reason people with cardiac issues should monitor their coffee consumption. Also they’ve been cases where people have induced arrhythmias and cardiac issues due to excessive consumption at a young age (very rare and requires a lot of coffee, so don’t be worried!). That being said there are studies which have linked caffeine consumption and decreased risk of cardiovascular disease, which has even been commented on by the European Society of Cardiology (ESC).2 The study used the UK Biobank, and consisted of over 400k participants, they compared non-coffee drinkers to drinkers split by number of cups per day (<1, 2, 2-3, 4-5, >5).3 Overall, they concluded that decaffeinated, ground, and instant coffee, particularly at 2–3 cups/day, were associated with significant reductions in incident cardiovascular disease and mortality. Ground and instant but not decaffeinated coffee was associated with reduced arrhythmia.
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As mentioned in the intro, there’s a lot of talk about caffeine and its longevity effect. This is as the natural sources of caffeine combine plant polyphenols which have natural antioxidant effects. A 2022 review, looked at various studies, also examined the effect of it on the risk of neurodegenerative disorders, and no study showed an increased risk. 4 They concluded that is has been shown that the antioxidant effect of pure caffeine has beneficial effects on health, e.g., neurodegenerative disorders, liver damage, and physical activity. BUT this can’t be fully extrapolated when it comes to human consumption of coffee as there are other products that also contribute to the antioxidant action. They also commented that the degree of roasting also plays role, and of course, added sugar and artificial sweeteners can actually antagonize the antioxidant action.
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To conclude, I personally think the positives outweigh the negatives and modest consumption, like a coffee a day (provided it is actual coffee and not a sugar-bomb with a touch of coffee) has some benefits. Maybe you’re even reading this while sipping on your morning coffee. But as everything, moderation is key and everyone is very individual in how they react and process caffeine.
As usual, I’ve added some links below. I hope you enjoyed - see you next week! :)
The reading time given doesn't justify the post for sure. So much info, thanks Sara!