Caffeine is a powerful stimulant that can help provide mental stimulation, in fact it is the worlds most consumed psychoactive drug. The media and opinion often portray caffeine as something that can be both good and bad for your health, so what are you meant to believe and how do you determine what is right for you?
Caffeine acts by blocking receptors for an amino acid called adenosine. Adenosine can help to slow the nervous system often acting like a sedative or relaxant when it acts upon the receptors in the brain, thus when caffeine blocks the receptor this results in increased stimulation, resulting in increased alertness, often the reason so many of us enjoy a cup of coffee.
Caffeine can be found in a variety of sources including coffee bean, tealeaf, kola nut, yerba mate, guarana and cacao and cocoa. It can also be synthesized in a laboratory and may also be added to medications and many dietary supplements.
Coffee and tea make up the most common sources of caffeine, with around 80% of all caffeine consumption coming from these two sources and the rest being made up mostly from chocolate & soda drinks. Caffeine is one of the most studied compounds and has been linked with:
- Improving exercise performance.
- Improving the function of the hormone insulin.
- Increasing fat loss.
- Improving memory function.
Caffeine has also been linked with reducing the risk of certain diseases/conditions such as various cancers, cardiovascular disease, type two diabetes and Alzheimer’s, although the research is a little weak in many of those areas and often relies upon observational/cohort studies which can sometimes be misleading depending on how the data was obtained from the study.
Having said that it still sounds pretty impressive so far, however is there another side to caffeine? Interestingly caffeine has also been linked with:
- Increasing blood pressure.
- Increasing the hormone cortisol, commonly referred to as a stress hormone.
- Interrupting sleep health.
- Increasing blood glucose, likely via the increase in the “stress” hormone cortisol.
- Irritation of the gut lining, often causing irritable bowel type symptoms.
- Exacerbating reflux symptoms.
- Increasing anxiety and risk of panic attacks.
- Increasing the risk of miscarriage and PMS type symptoms.
It should be noted that many of these risk factors or symptoms are short lasting, dose dependent and will vary from individual to individual.
So how can something cause so many potential positive and also a long list of negative effects as well, and why is it that the scientific literature and media provides so many mixed messages?
One area of consideration is how we metabolise caffeine. Interestingly some of us are fast metabolisers of caffeine and others slow metabolisers of caffeine, as a result how long caffeine stays in our system varies hugely, with the predicted half life of caffeine (the amount of time it takes for 50% of the caffeine consumed to leave your system) ranging from 2.7-9.9hours. What you will typically find is that fast metabolisers will often be able to sleep fine even after consuming caffeine later in the afternoon/early evening, whereas the most sensitive to caffeine and slower metabolisers may have their sleep effected even if consuming caffeine 8 or more hours before bed.
Slow metabolisers are often those who suffer with the jitters, anxiousness, heart palpitations and even panic attacks after consuming caffeine, sometimes even at very low levels.
Whilst around 50% of us have a gene variant that causes us to not metabolise caffeine as effectively, around 80% of the worlds population consume caffeine containing products on a regular basis. So who should think twice about regularly consuming caffeine? If you are the sort of person that is inclined to experience some of the following symptoms after consuming caffeine or you suffer with any of the following I would limit caffeine intake, perhaps choosing teas and decaf options instead:
- Rapid heart, increased anxiety or the jitters after consuming caffeine.
- Recent history of panic attacks or anxiety.
- Disturbed sleep after consuming caffeine.
- Loose stools or irritable bowel after caffeine consumption.
- If you already suffer with high blood pressure.
- If you are pregnant or breast feeding.
- If you suffer with osteoporosis or low calcium levels.
- If you suffer with iron insufficient anemia.
- If you suffer with bladder irritation.
- If you are taking any medications you should also look for any potential interactions between caffeine and the medications you are taking.
For almost all other individuals I have found little evidence to suggest caffeine consumption need be eliminated. I think as long as you are aware of how you are responding to caffeine and that caffeine does not appear to be causing negative impacts on your health then feel free to consume and enjoy. Caffeine should not be used to cover up how you really feel, so often it is the case that people have grown to depend on caffeine because of underlying issues with their energy levels or inadequate or poor sleep health. This is not a healthy relationship and the goal is to have the presence of mind to step away from caffeine if you feel there is a need to consume it, rather than just consuming for the enjoyment or using it as an occasional aid to physical or mental performance.
The Caffeine Comedown
Whilst I will encourage many people to ditch caffeine for around 4 weeks to see how they function without caffeine and to determine if there is a dependency on caffeine covering up some other underlying symptoms, the caffeine comedown can be quite significant and debilitating.
Like any drug you can experience some unpleasant side effects when coming off the substance. Caffeine comedown usually results in some level of drowsiness and often significant or dull headaches for around 3-5 days. I usually recommend coming off caffeine on a Friday, so you have the weekend to deal with the worst of the symptoms. With some people this can be a little too much and so they may choose to titrate their dose down rather than go cold turkey and that is fine as long as they perform the full 4 weeks complete caffeine free once they have titrated down and removed the caffeine.
What about decaf options?
Whilst there are options out there for decaffeinated drinks and on the most part this may be a good option for some, we should also consider the process involved in decaffeinating a substance. There appear to be some slightly healthier extraction methods. Two methods involve indirect and direct chemical solvent use and in many circles are seen as an inferior and potentially problematic method, however there is limited evidence of there being any solvents left after the processing and roasting of the bean.
Two other extraction methods that do not involve solvents include Swiss water process and carbon dioxide process, both chemical free options and with respects to the Swiss water method more flavour is generally retained where it can be lost more with the chemical based method. The CO2 method is costly so tends to be saved for large quantities of more commercial grade coffee. My personal opinion would be to choose Swiss Water organic decaffeinated coffee.
Caffeine Take Home Points
- We all respond very differently to caffeine, so determining whether it is right for you is very individual and should not be swayed by media headlines.
- Listen to your body as to whether caffeine suits you. If you are unsure then a short caffeine break can be a very good idea to reduce dependency issues with caffeine.
- Caffeine can be extremely useful to help optimise physical and mental performance when used wisely.
- Blanchard J, Sawers SJ. The absolute bioavailability of caffeine in man. Eur J Clin Pharmacol. (1983)
- Sachse C, et al. Functional significance of a C–>A polymorphism in intron 1 of the cytochrome P450 CYP1A2 gene tested with caffeine. Br J Clin Pharmacol. (1999)