• Question: What are the effects of caffeine on the brain and learning? Are there any studies looking at different aged children? What information do you think we should tell students who are consuming large quantities?

    Asked by Lia - WellcomeTrust to Joe, Kathy, Mark, Rebecca, Rod on 15 May 2015.
    • Photo: Mark Mon-Williams

      Mark Mon-Williams answered on 15 May 2015:

      Hi Lia

      I don’t work in this area (neuropharmacology) so my answer is just based on a case study… me!

      But perhaps a few points to make regarding your question:

      (i) It’s worth separating ‘performance’ from ‘learning’. My personal experience is that a bit of caffeine helps me perform better (e.g. concentrate on understanding the methodology reported in a paper I am reading in the morning). This tends to improve my learning. It may be that caffeine also improves my neural plasticity and so accelerates the ‘learning process’ – but this would be a different mechanism by which caffeine is affecting my brain.

      (ii) There is always an issue when moving between different ‘levels of description’. There may or may not be laboratory evidence for caffeine affecting neural learning processes (I simply don’t know this field) but there is a big gap between establishing some laboratory based effects and the implications for these observed effects within a real world environment (where you need to control for the myriad of other factors that affect something as complicated as educational learning). It would require a large scale epidemiological study or RCT experimental design to try and find out the impact of caffeine on some defined real world outcome (such as educational attainment). I’m certainly not aware of any decent studies that have addressed these issues in this way.

      (iii) It follows from the above that I wouldn’t be confident about advising students about their levels of caffeine consumption with regard to the effects of the drug on their learning capacity. I would be happy to share my personal experiences with them – and explain that I’ve always found drinking lots of caffeine to be ultimately unproductive (I get too jittery and don’t sleep well if I drink too much). I provide the general advice to my own tutees that I’ve ultimately learned that waking myself up with caffeine is a very poor substitute for a decent night’s sleep!

      best wishes


    • Photo: Joseph Devlin

      Joseph Devlin answered on 16 May 2015:

      Interesting question! There was a recent study in the US showing that the majority of children — including preschoolers — consume caffeine and that intake was highest in 12-19-y-olds (Ahluwalia et al. 2014). So it’s important to know what effect this has, if any, on learning. Evidence suggests that drinking a caffeinated drink acutely improved concentration, working memory, and sustained attention which led to faster maze learning times (Bruce et al 2014), consistent with Mark’s experience. A recent paper by Poole and colleagues (2015) looked at the effects of chronic caffeine consumption in pre-adolescent, adolescent, and adult mice during two types of learning: contextual learning (that depends on the hippocampus) and fear-conditioning (that does not depend on the hippocampus). They found that caffeine affected contextual learning but not fear conditioning. The effects depended on the levels of caffeine consumption — low levels actually enhanced this type of learning while higher levels impaired it. BTW, this was only in the young mice — caffeine had no effects on learning in the adults. These data suggest that caffeine affects the hippocampus during childhood & adolescence, while it is maturing, and this has knock-on effects on learning.

      Assuming these studies are robust and replicate well (this isn’t my area so I don’t know), the advice I would give to school-aged kids would be to take it easy with caffeinated drinks. Some is ok but don’t overdo it.

      Here are links to the three papers I mentioned. The Poole paper is particularly well written and interesting, IMHO.
      Ahluwalia: http://www.ncbi.nlm.nih.gov/pubmed/25240076
      Bruce: http://www.ncbi.nlm.nih.gov/pubmed/25046515
      Poole: http://www.ncbi.nlm.nih.gov/pubmed/25827925

    • Photo: Kathy Robinson

      Kathy Robinson answered on 16 May 2015:

      It would be interesting to know why some students feel the need to consume large quantities of coffee. Looking at the ‘related questions’ we could ask them about their sleep behaviours ( i.e. amount and pattern) and diet to see if there are any correlations between these factors and coffee consumption. Anxiety about school performance is another factor that may be implicated.

      If, for some students, it is sleep behaviour and they are consuming coffee so that they can stay awake or improve attention then maybe a good tactic would be to get them to read the THINK blog entry on teen sleep.