Why Do People Drink Decaffeinated Coffee?

Recent medical studies show that a moderate coffee consumption has more health benefits than drinking decaffeinated coffee: the positive effects of caffeine are added to those of other coffee components such as antioxidants. So when people drink a cup of decaffeinated coffee instead of this good old Joe, is it due to a personal preference or to a limited and outdated medical knowledge?

This raises the question of medical information in general and how people react or change their habits based on that information. Coffee is a good example: it illustrates perfectly what we want to point out.

A brief history of coffee throughout the ages

• Coffee has always been appreciated and it is still one of the most consumed beverage in the world since centuries.
• On the other hand, coffee always arose suspicion: it is black, strong, it alters the mind and has powerful physiological effects, no surprise then that coffee has always been a usual suspect.
• Our literature is full of stories and anecdotes about coffee and its dangers, as old as from the 17th century, see for instance the famous Women's Petition Against Coffee in 1674 and how men replied to that.
• In more modern ages, the scientific population has conducted thousands of studies during decades and has informed essentially about the risks.
• In the 60s and early 70s, several studies attributed a risk factor of heart disease and bladder cancer to coffee: in the global opinion, drinking coffee became a risky pleasure and decaffeinated coffee developed accordingly.
• Years later, hundreds of medical studies have been conducted and surprisingly most of them have refuted the previous findings: the relation between coffee consumption and risk of heart diseases or bladder cancer has been denied by several studies, and coffee has even been presented as reducing the risk of other diseases such as liver cancer, type 2 diabetes and neurodegeneration.

So what should people believe?

It seems like scientists have been ambivalent on this topic: couldn't they state once and for all if coffee is good or bad for us?
Why is it so hard for doctors and researchers to take a stand about coffee and health?
As you can guess, doctors are serious people and they don't communicate widely unless there is a clear evidence proven by scientific studies, submitted to their pairs and approved by the whole community. If there is any doubt or if this medical communication might be misunderstood or harm people, they stay cautious and ask for further researches.
As a consequence, unless scientifically proven, you won't hear from them that "this is white and this is black", you will more probably hear about shades of grey.

In the case of coffee and health effects, the ambivalent communication is mainly due to the methodology of these medical studies: they are "observational" and not "interventional". Let us clarify these methods in a few words.

Observational versus interventional studies

Observational research methods take their name from the fact that the investigator simply observes, no interventions on the studied population are carried out by the investigator. The main categories of observational research are cohort studies, cross-sectional studies and case-control studies.

• Cohort study: this type of observational study selects a large number of persons before the condition appears and follow up each subject during years, and then will analyze at the end the probable causes by comparison between people.
• Cross-sectional study: these studies select subjects at one point in time only (today) without regard to the condition and deduct a risk factor from the look at each subject.
• Case-control study: this last category of observational research selects only subjects who have the condition, then look back at the history of each subject and then analyze a risk factor by comparing to a group having no condition.

Limitations of observational studies

These observational methods are scientifically valid (sample, control group, quality of measurements, distortion) and they are used mainly for the research of risk factors, or when other methods can't be used for ethical reasons (danger for the subjects) or practical reasons (large scale studies running for decades). Of course the weakness of observational studies, compared to randomized, double-blind, and placebo-controlled clinical trials, is that the researchers deduct a probable risk factor but without unquestionable evidence. With a randomized controlled trial, you get evidence. With an observational study, you get a risk factor and a probability of disease, but no evidence.

Today we know that it is highly probable that coffee has more benefits for human health than harms, but highly probable does not equal 100 percent certainty. Our common sense has then to prevail, in order to act based on the level of probability, if certainty cannot be achieved: each one of us has to assess the strength of the evidence by comparing the risks to the benefits.

To come back to our question: why do so many people drink decaffeinated coffee? Probably not due to a better taste compared to coffee. Either because they want to avoid some effects that they really experimented by themselves (sleep disorder for instance) or because they think that caffeine is bad for them (blood pressure, pregnancy etc.) or simply they are not sure and they apply a precautionary principle.

Here is our own point of view: based on the in-depth analysis we did recently, we see the balance of risks and benefits of coffee as a bell curve based on consumption: a few cups will bring positive results until a peak is reached, depending on individual factors, and then after a certain limit the negative effects will be higher than the potential healthy effects. The safe attitude is then to stay under a reasonable limit: in that way you won't have the maximum benefits but you stay on the safe side. Then the good question is: what is a reasonable consumption for you? Again, it can vary but the usual limit is set to 4 or 5 cups per day.

By the way, did you notice how much this approach about dosage and the resulting risks and benefits balance also apply to this other alkaloid, ephedrine?

Last words for decaf drinkers

Stay informed (but don't trust all information found online, check the references), focus on yourself (your body knows), use your common sense... and you will be fine!