‘Coffee strengthens memory and intellectual capacity’, says
this sugar sachet. Is this true? I was all set to dismiss this as a marketing
ploy, but there does seem to be some evidence to support the claim.
Overall, the results about the effect of caffeine on memory
are mixed.
In the short term, caffeine can ‘strengthen intellectual
capacity’, particularly in sub-optimal conditions – i.e. if the drinker is
feeling tired or working at night. If the drinker is working on more complex
tasks, there are still positive results linked with caffeine consumption but
it’s not so easy to say that this is actually down to the caffeine, rather than
other factors. And in some studies, caffeine was even found to impair memory.
This 2002 literature review
in the Archives of Medical Science in the US National Library of Medicine
states that regular caffeine users have higher mental functioning (!), although
again this may not be down to the coffee on its own.
An article from the same source
says that caffeine improves reaction time but has no effect on long-term
memory.
To my surprise, drinking coffee in midlife is linked to
reduced incidence of dementia,
although this may not be down to the coffee – correlation does not mean
causation, of course, and it’s not clear what the exact mechanism might be. Randomised
controlled trials (isolating caffeine as far as possible as the only variable) are
lacking.
Commentators agree that the safe limit for coffee is 400 mg
a day – about 4 cups. ‘It seems safe to inform the general public that coffee
drinkers need not fear for their health’, says this 2017 article. Reassuring, but certainly no good for a sugar packet slogan.
So how should that sugar packet slogan be rewritten to be
more rigorous? Something like: ‘studies show that coffee might strengthen memory
and intellectual capacity in the short term’. Not as catchy, but still… surprising,
I must admit.
And let’s not forget the other benefits of coffee – the way
it brings people together, offers a break from work and is of course is a good
procrastination tactic. So here’s Meret Oppenheim’s 1936 surrealist work Luncheon in Fur to highlight the cuddly
side of coffee.
