This week we have Sammy Eden, a final year PhD research student at the University of Bath and the University of Exeter, studying the role of caffeine and physical activity and how they influence mood in individuals with bipolar.
When talking about caffeine, people often say it’s “like a drug”… Well, caffeine is a drug. In fact, it is the most commonly used mind-altering drug worldwide, with a whopping 80 % of people in developed countries consuming it every day. Coffee and tea are the most commonly recognised forms of caffeine, but it is also present in energy drinks, soft drinks (such as coke), chocolate and medications we buy over the counter. Coffee is the second most commonly consumed drink worldwide, after water and many individuals are more likely to have caffeine each day than eat fruit and vegetables (click here).
Just like many other dietary aspects, guidelines for daily caffeine consumption do exist. The European Food Safety Authority (EFSA), is an international organisation which provides scientific advice on food safety and they have established recommend consumption guidelines. The EFSA deem it to be safe for healthy adults to consume up to 400 mg of caffeine a day…this is the equivalent to ~ 4 cups of coffee. However, our sensitivity to caffeine (and the effects it has on our bodies) are affected by factors such as age, biological sex, weight, medications we take, genetics and lifestyle behaviours i.e. whether we smoke (click here).
Caffeine can have very noticeable effects on our energy levels and our mood. It can help us to feel more alert and energised, increasing our ability to think, making us more productive, and less tired or sluggish. It does this by stimulating our central nervous system and interacting with the neurotransmitters adenosine and dopamine in the brain (I will go into more detail about exactly how this works another time!). We can experience changes in energy and mood after consuming relatively small doses of caffeine. We absorb caffeine into our bodies relatively quickly, with the mood and energy boost noticeable after ~ 1 hour. Caffeine also has a half-life of ~ 4-6 hours. This means it takes ~ 4-6 hours for the caffeine levels in our bodies to reduce by half. However, if you regularly consume caffeine and then refrain from caffeine, you can experience withdrawal symptoms such has headaches or feeling irritable and sleepy.
In addition to the positive effects caffeine can have on our mood and our energy levels, caffeine can also have other benefits to our health when we consume it in moderate doses. Caffeine can help reduce the risk of disease such as cardiovascular disease, heart disease, stroke and type 2 diabetes (click here). It has also been found that having caffeine regularly can lower the risk of developing depression (click here). Caffeine contains polyphenols which are micronutrients which have lots of health benefits as they are full of antioxidants which help to stop damage to our cells (click here). Some of the health benefits of polyphenols include their ability to assist with digestion, control our weight, and prevent long term health conditions (click here). You might also be interested to know that coffee can also be beneficial for our gut health. Unlike other drugs, caffeine is not addictive, but people who regularly consume caffeine will build up a ‘tolerance’ to it, meaning they have to consume more of caffeine for it to have the same effect.
The take home message: Many people consume caffeine every single day. When consumed moderately and in safe doses, caffeine can have an array of benefits for our physical and mental health.