Updated: Mar 11
In previous article we looked into the healthiest brewing methods.
We concluded that filtered coffee and instant coffee are preferred if you like to drink coffee multiple times a day.
This is mainly because unfiltered coffee can raise your LDL cholesterol significantly, in comparison to these two brewing methods, which in turn increases your risk of cardiovascular disease like heart disease (1), (2)
You don't have to be a long-term coffee drinker for the antioxidants to be able to show up in the bloodstream. Even the antioxidants from a single cup of coffee can be detected soon after consumption. (5)
Antioxidants can help lower inflammation which will be discussed further on.
Since coffee can be relatively high in antioxidants, wouldn't that suggest that coffee is in fact anti-inflammatory?
There are a few studies where they measured an increase in inflammation among coffee drinkers, but in one of those studies people consumed coffee containing up to 900 mg of caffeine daily for several weeks. (7) That's a lot of caffeine as we've seen here.
To put it into context, it's more than double the maximum recommended amount, as set in multiple countries.
There is another study though, where participants drank less than the maximum recommended amount, that shows that the consumption of coffee is linked to an increase in inflammation. (8)
But an overview of several studies on the other hand, concluded that coffee for the most part, has anti-inflammatory properties. (9)
Now, several of these studies have been funded, at least partially, by coffee companies, (10), (11) so we shouldn’t take these into the equation. Industry funded research is significantly more prone to bias. (12), (13)
Obviously, that makes sense if you think about it. If you sell something, you want to make it look as good as possible in order for your business to profit.
So what if we account for industry bias?
If we pool all the studies on coffee and inflammation together and account for industry bias, overall there seems to be some indication, although hard evidence remains inconclusive, that coffee may be associated with an increase in adiponectin, which is regarded as an anti-inflammatory compound.
The study (8) that measured some inflammation was a randomized controlled trial, that was regarded as a quality study according to the researchers from the meta-analysis that looked into coffee and inflammation. (14)
They measured an increase in the anti-inflammatory adiponectin, but one inflammatory marker they tested for, also increased.
Based on this, coffee seems like a double-edged sword. It may be anti-inflammatory from one side and it may be somewhat inflammatory from another side.
This outcome came after drinking caffeinated coffee. Decaffeinated coffee interestingly didn't show an increase in inflammation, but a decrease. Although in a completely different inflammatory marker than the aforementioned ones.
This shows coffee is a complex substance. Not surprisingly, since it has over a 1000 different compounds. (16)
What’s interesting in all of this, is that the total chlorogenic content (a class of antioxidants) of the coffee, wasn’t that high. (17)
Perhaps THIS is the missing piece in our coffee puzzle.
Would the inflammation still have occurred if the antioxidant content was higher?
To answer that question we need to understand the link between antioxidants and inflammation.
Antioxidants for inflammation?
A rise in certain inflammatory markers in the body is a sign of chronic or low-grade inflammation. It is a lingering inflammation, unlike an acute inflammation that develops after sustaining an injury, which clears within a short time frame.
What role do antioxidants play then?
The body has mechanisms in place to counteract oxidative stress caused by free radical formation. It produces antioxidants, either naturally generated or externally supplied through food. (23)
This is vitally important to understand, because free radical damage contributes to the etiology of many chronic health problems such as cardiovascular and inflammatory disease, cataract, and cancer. (24)
Generally they are things we, as humans, try to avoid as best as we can.
In short: If we lack the antioxidants to stabilize the free radicals, they can cause damage to cells, which leads to oxidative stress, which in turn leads to inflammation, which then leads to disease, which brings us less vitality, more medical bills, more doctor visits and sometimes impressive looking scars due to the after-effects of some kind of surgery.
As you can see, antioxidants seem to be something you want to have enough of in your diet.
There are a multitude of inflammatory mediators that can be measured in the human body. It is a rare phenomenon that every single marker is tested for in scientific studies.
Therefore a high antioxidant coffee may the best option, to at least lower the chances of any (other) inflammatory effects it might have.
How do you know what coffee has a higher content of antioxidants?
So, instead of a dark roast go for a medium roast, or preferably, a medium low roast if you can.
We know that espressos generally have a higher antioxidant content than filtered coffee. (27) Antioxidants in espressos can vary however, because of different extraction mechanisms among espresso machines, that influence total antioxidants. (28)
What is a constant however is the higher amount of the cholesterol raising compound cafestol. So even though it may have more antioxidants, daily consumption, especially multiple times a day, may have more downsides than it has upsides.
Maybe we can take a lesson from the Ikarians in Greece.
They consume high antioxidant coffees in the form of greek style coffee, similar to Turkish coffee, where there is no filter of any kind involved.
Higher coffee consumption among the Ikarians was associated with better endothelial function. (29)
Endothelium is the inner lining of our arteries, that plays a pivotal role in regulating blood flow. (30)
Although the study design can’t prove whether the improved endothelial function is indeed caused by the coffee intake, it may offer some valuable insights regardless. That's because Ikarians are part of one of the longevity groups also known as Blue Zones. Their diets are vastly different from the average western diet, where chronic inflammation is a common phenomenon. (31), (32)
So, whether or not coffee contributes to their antioxidant intake, their diet already has a better foundation to start with. It is more likely to also offset some of the potential negatives of their coffee intake. That’s why declaring coffee the hero in this context may not be accurate.
And there are people, like in Scandinavia, with a higher consumption of high antioxidant coffee, who don't fare as well as the Ikarians and who aren't part of the Blue Zones. (36), (37) Relying on coffee for most of your antioxidants doesn't seem like a good strategy. So if you want to maximize its benefits and reduce potential negatives, then looking at what you consume besides coffee is vital.
Interestingly enough instant (soluble) coffee can even have higher antioxidant contents than espresso in some cases. (38) Robusta is commonly used for the processing of instant coffee, so perhaps that could explain the difference.
When it comes to inflammation a higher antioxidant coffee has more anti-inflammatory properties and it would be your safest bet when it comes to frequent coffee consumption.
Lower roast coffees that are higher in antioxidants can be made both filtered or unfiltered.
That means you could still consume high antioxidant coffee, regardless of the brewing method.
Though unfiltered coffees can be high in antioxidants, they are also high in compounds like cafestol which are less beneficial. In this context it would probably be better to consume unfiltered coffee less frequently than filtered coffee.
However, the role your diet can play is more significant than the kind of coffee you drink.
If you eat a mostly inflammatory diet, typical in western civilization, then you can't expect high antioxidant coffee to be your saviour.
On the other hand, a more anti-inflammatory diet could very well offset any negatives coffee might have.