The verdict on games, crosswords and other ‘brain-boosting’ exercises.
The brain is like a dense conglomerate of muscles, each one dedicated to a particular task. Exercise any one of them and it will get stronger, but you need to exercise them all to improve your general cognitive ability. If you practise adding up figures all day, for instance, you will get very good at adding up figures, but if you never resort to estimation – a skill performed by an entirely different brain ‘muscle’ from arithmetic – you will be no better than anyone else at judging, say, the size of a crowd.
Brain-training has been dogged by the difficulty of developing exercises that improve functioning across the brain rather than in one small part. It’s now recognised that suites of exercises – those that package together visual search exercises with motor coordination challenges and word-retrieval games, for instance – can have broad benefits. However, if you have a healthy brain capable of a normal range of skills, the best exercise you can get is real life. Taking an active part in the community, enjoying art, listening to music, engaging politically and enjoying a rich social life – these are the best training of all.
Not all of us, however, have optimally healthy brains. Nor is it always possible to develop or practise the full range of cognitive skills. Brains degenerate physically with age, just like every other part of the body, and many people can’t live life to the full because they’re locked into repetitive work or cut off for some reason from intellectual stimulation.
When people get older, their neurons tend to be less excited by environmental stimuli. This is partly due to reduced hormones and neurotransmitters, but partly because fewer events are novel and stimulating. Our brains have ‘been there, done that’, and are not inclined to use too much energy doing it again. Just as brain activity primes the brain to activate in the same way again, subdued brain activity reduces future activity. So, whether you go for computer gaming, reading, listening to music or playing sport, the first thing brain exercise should do is get you excited.
The second thing it needs to do is to work as many cognitive muscles as possible. Crosswords are the famous go-to exercise because they involve several elements of cognition: memory, problem-solving, and spatial sensitivity (noticing how the words fit together). If you do crosswords too often, however, you may get so good at them that they no longer stretch you. The person who boasts that they complete a broadsheet cryptic puzzle every day may be doing less for their brain than someone who struggles to solve a single clue in a much simpler puzzle.
The same is true of Sudoku. The numbers game can be very challenging, especially for newcomers, but doing Sudoku every day merely makes you better at Sudoku – a skill that is quite difficult to find a use for elsewhere.
Should you take supplements?
A varied diet should provide all the brain-healthy nutrients you need, but could you benefit from taking more of them? Omega-3 – the fatty acids found in fish such as herrings, sardines and mackerel – is the supplement best known as a brain-booster. But the evidence for its effects is underwhelming. A 2012 review by the Cochrane organisation – widely acknowledged as an authority on health research – found no evidence that omega-3 reduces the risk of cognitive impairment, while a 2015 meta-analysis by Canadian scientists concluded: “Omega-3 fatty acids, B vitamins, and vitamin E supplementation did not affect cognition in non-demented middle-aged and older adults.”
Similarly, evidence for the herbal supplements ginseng and ginkgo biloba fails to stand up to scrutiny. The same goes for practically every other so-called brain-booster. The Natural Medicines Comprehensive Database, a non-commercial organisation that continuously collects and reviews data, failed to find a single proven effective supplement among more than 50 they assessed. They rated a few as “possibly effective” but most simply had “insufficient evidence” to make a judgment.
Lack of proof of efficacy is not, however, proof of lack of efficacy. The large-scale, expensive research needed to show beyond doubt whether something works is usually done only for medicinal drugs, so it’s not surprising that there’s no concrete evidence for the effects of supplements in healthy people.
Supplements are not without risk – they can interfere with medicines and produce nasty side effects, especially if too many are taken. However, a supplement that gives the recommended daily dose of required vitamins and minerals may be a good idea if you feel your brain needs a boost, especially if you think your diet may be deficient in some way. Just consult your doctor if you experience any side effects.
Can electrical stimulation and ‘smart drugs’ boost brainpower?
Strapping electrodes to your skull to stimulate your brain with a buzz of electricity might sound scary, but done properly, non-invasive ‘transcranial direct-current stimulation’ (tDCS) is safe – it uses a minute charge and feels tingly but not painful. tDCS is extremely well-researched – it features in more than 2,000 studies published in mainstream academic literature – and has been found safe and tolerable, even for children.
So would you benefit from tDCS? Many studies have found that it improves a wide variety of cognitive skills, and helps relieve mood disorders such as depression, but there are some studies that show minimal or no benefit. Generally, around 10 to 20 minutes of tDCS a day seems to have modest, cumulative effects. Most studies have been conducted on people with brain problems, however, so results can’t always be applied reliably to those with healthy brains.
Another thing to bear in mind is that the effect of tDCS depends on where the electrodes are placed on the head. There is a ‘sweet spot’ (the dorsolateral prefrontal cortex’) which tends to be the default option because it has positive effects on mood, memory and cognition. Other benefits require different placements. Some tDCS devices come with a ‘map’ of electrode locations.
There are dozens of DIY devices on the market – established makes include foc.us and TheBrainDriver. To date, there are no legal barriers to the direct-to-consumer sale of tDCS devices, but do your research before buying. Some are expensive machines aimed at research, which include features that are unnecessary for home use. At the other end of the spectrum, the cheapest, home-made tDCS devices may not have reliable timing mechanisms or adequate safety measures, such as an automatic cut-out in the event of an electricity surge. There is limited independent research on how well consumer tDCS devices work, however.
‘Smart drugs’ is an umbrella term for hundreds of substances claimed to boost brainpower. About 12 per cent of university students are thought to use smart drugs in the hope of improving their performance, with many available to buy easily online.
Also known as ‘nootropics’, these include some prescription drugs such as Ritalin and Adderall, which are licenced for attention-deficit disorders, and modafinil, a treatment for narcolepsy. These have proven benefits for patients, but whether they work for healthy people is less clear. And they can have adverse effects, so you would be unwise to take them without advice from your GP.
Smart drugs also include herbal supplements, which may claim plenty of proof of efficacy, but have not been put through the rigorous trials needed for prescription medication.