Tea or coffee is often the favoured brew for those who are tired and in need of a caffeine boost. But is this really the best way to make ourselves more alert? Michael Mosley tested caffeine against some unlikely alternatives – sage, fudge, chewing gum and electric shocks.
How effective is caffeine for improving alertness? I drink lots of tea and coffee, so I assumed the answer is “very”. But it is always worthwhile having your assumptions challenged.
So the Trust Me team asked Professor Peter Rogers of Bristol University to put caffeine to the test. He recruited a group of 20 people, 10 of whom never normally touch caffeine. The other 10, regular caffeine imbibers, were asked to turn up for testing having abstained for at least 12 hours.
Both groups were measured for mental agility, concentration and dexterity. Then they got a drink with a good jolt of caffeine in it. I found the results surprising, not to mention disappointing.
“Overall, regular caffeine consumers who’d been without caffeine overnight, were slower on the reaction time task, were sleepier and were less mentally alert than non-users,” Professor Rogers said.
They did improve after they got a caffeine drink, but only up to the level the non-users had achieved without caffeine.
When the non-users were given caffeine to drink their reaction times increased but they also became more jittery and anxious.
Professor Rogers says that, contrary to what most people believe, drinking lots of coffee on a regular basis won’t enhance your mental performance. Part of the problem with caffeine is we quickly develop dependency.
So if you want to give your brain a boost, what else is out there?
Next we asked Dr Andy Johnson, of Bournemouth University, to test the impact on afternoon drowsiness of eating sugar, sage (the herb) and chewing gum.
He lined up 24 volunteers and in the morning did some tests to measure alertness. Then, in the afternoon, our volunteers were randomly allocated to either chew gum, eat fudge, swallow a pill containing sage or a placebo.
One hour later they did some really boring tests. They repeated this process three more times over the course of the week, each time trying something different.
As expected, swallowing a placebo pill made little difference. The volunteers still felt drowsier in the afternoon. Eating fudge, if anything, made them feel slightly worse.