Coffee is the second most consumed beverage after water with approximately 1.6 billion cups consumed worldwide every single day (1). Despite this huge number, many people refrain from consuming it because of its active ingredient: caffeine. Caffeine is a stimulant that is found naturally in a number of foods/beverages, not just coffee! This includes tea and chocolate.

Caffeine exerts its effect on the body by blocking adenosine receptors (2). When adenosine can attach to these receptors it plays different roles depending on where it is in the body; for example, in the brain it helps to promote sleep and in the heart it reduces heart rate (3). Hence, when caffeine enters the bloodstream and blocks these receptors, it prevents these things from happening and so explains why we feel more alert after consuming a cup of coffee!

The amount of caffeine in different foods and beverages varies greatly. Some is naturally occurring whilst some products can contain added caffeine. Examples include (4):

  • 1 mug of filter coffee = 140mg caffeine

  • 1 mug of tea = 75mg

  • Can of Cola = 40mg

  • Small bar of chocolate = 25-50mg

  • Can of Red Bull = 80mg

So, what are the benefits of consuming caffeine?

  • Increases alertness: probably the most obvious effect for any coffee drinkers, caffeine helps to improve our alertness so can be helpful before studying or a work meeting. One study found that this effect is further enhanced if consumed with glucose (5).

  • May improve athletic performance: caffeinated drinks are very effective pre-workouts since they stimulate a raised heart rate and increase alertness.

  • Coffee, specifically, is a source of antioxidants: our body is constantly under attack from free radicals, which can damage cells in our body like proteins and DNA. Antioxidants inhibit these free radicals and can hence reduce our risk of diseases like cancer and may reduce the physical effects of ageing (6).

Why might I want to consider reducing my caffeine intake?

  • Impacts sleep quality

  • Can impact anxiety

  • May trigger GI discomfort

  • Not advised above 200mg for pregnant or breastfeeding women

But remember, daily recommendations for caffeine consumption are as follows:

Adults: <400mg/day

Pregnant women: <200mg/day

Caffeine can affect us all differently depending on factors such as age, body composition, sex and activity levels. Ultimately, like everything in life, it has its pros and cons so don't think you need to switch to decaf immediately!






(5) Grant CL, Coates AM, Dorrian J, Paech GM, Pajcin M, Della Vedova C, et al. The impact of caffeine consumption during 50 hr of extended wakefulness on glucose metabolism, self‐reported hunger and mood state. Journal of Sleep Research. 2018;27(5):e12681.


36 views0 comments

Recent Posts

See All

Completing the Trainline Challenge would not be possible without the support of all my sponsors. A huge thank you to everyone who is supporting me and has provided myself and the team with the means t