6
Pills, Powders, and Push-ups:
what works (and what doesn’t)
Gerrit Deems from Nijmegen didn’t regard it as much of an achievement himself, but of course it was. On 19 April 2011, he obtained his PhD at the ripe old age of 89. Having worked as a sales representative and later as a social worker, he began studying philosophy when he was 43 and completed a theology degree at the age of 69. He then decided to expand his final paper, about the priest Alfons Ariëns (1860–1928), a key figure in the Catholic trade-union movement in the Netherlands, into a thesis. In an interview in the newspaper NRC Handelsblad, he admitted he had had his ‘ups and downs’ while writing the thesis.[1] But the dozen or so young PhD students I have supervised in recent years had the same problem. Deems’s thesis, of course, gave him the perfect opportunity to keep his mind sharp. If people don’t stay active as they age, they can stagnate. And he agrees: ‘Being retired actually creates the space to do your own thing and to develop your talents even further.’
Advising everyone over the age of 65 to write a thesis is possibly going a step too far. But there are many other activities that make demands on your brain. So the question is this: are intellectual pursuits good for the ageing brain, and do they prevent decline? The Roman philosopher and statesman Marcus Tullius Cicero (106–43 BCE) wrote: ‘I have no doubt that it is [impaired] in persons who do not exercise their memory.’ Was he right?
All kinds of remedies are advertised on TV, on the internet, and in newspapers and magazines to keep your brain sharp as you age — from Sudoku puzzles and computer games to omega-3 fatty acids and extra vitamins. Scientists and pharmaceutical companies are busy developing medications to improve memory and other cognitive abilities. But do these things work? Is it in fact possible to improve cognitive function, or can we at best achieve a delay in its decline? In this chapter, we’ll take a look at what works and what doesn’t.
PILLS
British professor Linda Partridge is a founding director of the Max Planck Institute for Biology of Ageing in Cologne, and plays a pioneering role in research into ageing. While in the Netherlands for a lecture in November 2011, she gave an interview to de Volkskrant. According to Partridge, advances are being made in research into healthy ageing, and in a few years a special pill for daily consumption by older people will come onto the market. This pill will ensure that they remain healthy for longer. She called it a ‘polypill’ because it will have multiple ingredients, including an anti-cholesterol drug and aspirin (both reduce the risk of cardiovascular disease). It will probably also contain something that keeps insulin levels stable, which is good for metabolism. Many pills for older people already exist, but they produce only a single effect, such as the anti-cholesterol drug, and then only in a certain group of people (those whose cholesterol levels are too high, for example).
What Professor Partridge did not mention were medications that would directly improve cognitive skills. That is because these are not yet sufficiently developed. It is even unclear whether it will be possible to improve, say, memory and concentration with a single pill without side effects. But lots of research is going on into substances known as cognition enhancers, which can improve memory and other cognitive abilities. Examples include donepezil, memantine, and modafinil. The first two of these are already being used in the treatment of Alzheimer’s. Small improvements in memory and concentration have been noted in patients taking these drugs, but though they sometimes slow the rate of decline a little, they do not stop the progress of the disease.
Donepezil increases the amount of acetylcholine (which is important for memory) available in the brain. As yet, little research has been done into its effectiveness in healthy seniors with memory problems. An American study of 20 people aged 72 showed that it improved the ability to recall words, but only if the person had thought about the word first. In this experiment, people were asked to say if they thought a particular word was pleasant or unpleasant. It is easier to recall words you have ‘processed’ in this way than if you merely read them. Donepezil reinforces this mechanism, improving storage in the brain. Another study of people aged between 60 and 80 established that this drug promoted REM sleep (when most dreaming takes place) and memory consolidation. The two proved to be linked. This is very interesting because an increasing number of studies have shown that, even in younger people, REM sleep is important for retaining relevant information and experiences. Another study, which used a driving simulator, investigated whether donepezil could help older people remain alert while driving. However, the drug proved no more effective than a placebo.
Memantine affects three neurotransmitters simultaneously: glutamate, serotonin, and acetylcholine. Glutamate is widely present in the brain and activates neurons. Like acetylcholine, it is vital to learning and memory. Though there is sufficient evidence from animal research and studies of Alzheimer’s patients that memantine can have a beneficial effect on cognitive function, the drug has not yet been properly tested in healthy people with memory problems. Currently, a new class of compounds called ampakines is being tested on animals in experimental research. Ampakines also act via glutamate receptors and appear to facilitate learning and memory.
Finally, there’s modafinil, which is already used as a medication for people with sleep disturbance (narcolepsy). Because patients became more alert after taking the drug, researchers decided to investigate whether it could improve concentration in people suffering from cognitive decline. We don’t exactly know how modafinil works in the brain, but there are indications that it increases levels of the neurotransmitters dopamine and histamine. Histamine makes us alert, and dopamine improves attention and working memory. Research has shown that modafinil can enhance both these functions in young, healthy people who take it once as part of a study, as well as in people with ADHD or schizophrenia. No research has as yet been done using healthy seniors with memory problems or people with MCI.
To conclude this section, we should look at another pill that can improve memory: the placebo. Researchers at Victoria University of Wellington in New Zealand gave one half of a group of older people a pill they were told was good for the memory. In reality, it was a sham drug, with no active ingredient. Next, they were set a demanding memory task, which involved recalling a series of actions in the right order. Subjects who had taken the pill performed better. This study confirms that expectations play an important role in cognitive performance. We saw earlier that stereotypical ideas about older people and memory loss in ageing are also common among older people themselves, and these can affect their performance. Though placebo research shows that sham pills can reduce negative expectations, improving awareness in society might be more effective in the long run. Up to now, the positive aspects of ageing have received little publicity, but more knowledge about the ageing brain could lead to a reassessment and to fewer stereotypes. I hope this book will contribute to that process.
NATURAL SUPPLEMENTS
People have always tried to improve their health by using medicinal herbs. There is already a vast storehouse of information on their use in China, from thousands of years ago. Other cultures have also attached great value to herbs. For example, the Wisdom of Sirach, a work of ethical teachings from the 2nd century BCE, says: ‘The Lord has created medicines from the earth, and a sensible man will not despise them.’ And indeed, contemporary Western society is far from despising them. Many people buy herbal preparations from pharmacies and health-food shops, without always being aware that conventional medicines often contain natural substances with medicinal effects. Herbal supplements can be effective in treating physical complaints and psychological problems — St John’s wort, for instance, can be useful in combating mild to moderate depression. But can they improve memory, concentration, and thinking skills?
Though claims are made for all kinds of products that supposedly act on the brain, only two have been scientifically proven to improve function or delay decline: vitamin B12 and omega-3 fatty acids. There is much evidence that B12 is important to cognitive function in older people.[2] Vitamin B12 deficiency is associated with a greater risk of cognitive decline in ageing, and around 15 per cent of older people have such a deficiency. Symptoms of low B12 levels include pallor, a feeling of weakness and fatigue, light-headedness, and a lack of appetite. Of course, if you notice these symptoms, they can be the result of a different condition, so it’s important to consult your GP. A deficiency is unlikely in people who eat a varied and healthy diet. Blood tests are needed to establish B12 levels, and if there is a serious deficiency, your doctor may prescribe supplementation in the form of injections. A recent study conducted by the University of Chicago showed that a B12 deficiency in older people is associated with less grey matter in the brain. This finding confirms how important it is to consume foods rich in B12 (for example, beef or cod). B12-enriched soy milk is also readily available, while a yeast extract such as Marmite or Vegemite contains added B12, too.
Yet there is no hard evidence that taking extra B12 improves cognitive function. Not enough good research has been done in this area. Researchers in Australia asked 900 people between the ages of 60 and 74 to take either folic acid and B12, or a placebo every day for two years. The group that took the B12 and folic acid did better in memory tests than the group who took the placebo. In fact, folic acid alone can lead to improved function. A Dutch study involving 818 subjects who took folic acid or a placebo on a daily basis for three years found that the group taking the folic acid scored better on memory and processing speed. But there have also been studies that found no improvement in people taking B12. In French research involving over 800 people between the ages of 45 and 80, half of the subjects took a combination of vitamin B12 and omega-3 fatty acids; the rest, a placebo. All of the participants had cardiovascular problems, varying from heart attacks to brain haemorrhages. After four years of daily ingestion, neuropsychological testing found no differences between the two groups. Only the people who had experienced a brain haemorrhage improved their performance, and then only on a single test. The B12 taken in the Australian study might have had more effect because it was combined with folic acid, which promotes B12 uptake. Researchers at Wageningen University have established that folic acid and B12 can be added to bread. If all older people were to eat this enriched bread, B12 deficiency in this group could be eradicated completely.
Taking B12 to improve mental capacities may only be effective in people who have a deficiency, rather than in the general population. Though strictly speaking they are not suffering from a deficiency, a quarter of seniors have low levels of this vitamin, so supplements are advisable. Your GP or local pharmacist can advise on whether extra vitamins are necessary, and if so, in what amounts.
Omega-3 fatty acids have already been mentioned. They are found in oily fish such as mackerel, herring, and salmon, and are good for the heart and blood vessels. They also have a beneficial effect on the cell wall in neurons, enabling better transport of substances needed by the neuron to function effectively. A study among 107 people (average age 78) showed that those who regularly ate oily fish performed better in memory and concentration tests and had more grey matter in their brains. The improvement was linked to the levels of omega-3 fatty acids measured in the blood. Another study followed a group of older people over a period of 13 years, recording their consumption of fish. People who ate more fish complained less of cognitive decline. There may thus be a link between fish oil and improved cognitive function, but, once again, the key question is this: can you improve your mental capacities and prevent Alzheimer’s by regularly eating oily fish or taking daily fish-oil capsules? Research using apes and rats found that memory did improve, which means that there is, at the very least, a possibility of benefit to the brain. But research on humans has yet to give an unambiguous answer.
A couple of studies did find an improvement in human memory. One, a Chinese study using almost 1,500 subjects over the age of 55, found a link between consumption of fish-oil capsules and fewer cognitive deficits after 18 months. But there are also a number of high-quality studies that reported no improvement, even after 26 weeks of fish-oil consumption. So though there is no guarantee that it will improve our memories and concentration, eating oily fish regularly (the guidelines say twice a week) appears to be good for your brain. And there is evidence that it is good for your cardiovascular system.
Another natural supplement claimed to be beneficial for the ageing brain comes from Ginkgo biloba, a tree species originating in China. The tree can live as long as 1,000 years and has distinctive fan-shaped leaves, from which ginkgo is extracted.[3] The herb helps the body to rid itself of free radicals, waste products that can damage brain tissue. Ginkgo is thus an antioxidant. It can also protect the structure of cell walls in neurons, and it promotes healing in damaged areas of the brain by stimulating the uptake of glucose. Furthermore, an Australian study showed that ginkgo can strengthen brain-wave activity related to working memory, and the researchers thought that this was related to a more efficient working memory.
Though these findings primarily come from animal research, it is not unlikely that ginkgo has similar beneficial effects in humans. A couple of studies have found small improvements in the memory of Alzheimer’s patients, but a similar number found no improvement. The number of participants in these studies was too small for reliable conclusions to be drawn. So far, too little research has been done among healthy seniors.
Other substances that can temporarily improve concentration include coffee and ginseng. Like ginkgo, ginseng (Panax ginseng) comes from China. This time, the active ingredient is in the roots rather than the leaves of the plant. Even though it is one of the most commonly used herbs in the world, very little high-quality research has been done into its effects in humans. This is possibly because there is little to be earned from ginseng, a natural product that cannot be patented — the pharmaceutical industry prefers to invest in large-scale research into new medicines because they can recoup the investment through sales. The active ingredients of ginseng are ginsenosides (also known as panaxosides). Animal research shows that these can have a positive effect on acetylcholine levels in the brain. They can also activate energy metabolism in the hippocampus.
COGNITIVE TRAINING
An advertisement for the popular Nintendo game Dr Kawashima’s Brain Training features a fit-looking 50-year-old who smiles as the screen reports that he has a ‘brain age’ of 46. Just before receiving this good news, he has solved several mathematical and other types of puzzles. The computer keeps track of his score and compares it with those of other players. In another advertisement, you see a woman of about 50 looking disappointed when she learns that her mental age is 63. But there’s hope: she can improve her mental abilities with Brain Training!
The idea of 100-year-olds concentrating all evening on their Nintendo games is perhaps rather strange. But that is exactly what British centenarian Kathleen Connell does, according to The Telegraph. ‘It’s absolutely super, I don’t know what I’d do without my Nintendo,’ said Connell, who plays other games on it, including Scrabble, to keep her mind fit. Brain Training consists of different tasks to train memory, concentration, and speed of processing. Some take the form of sums, puzzles, or language lessons, while others are more like standard computer games. In one of the tasks, you have to count how many people are on the screen, and then a house is placed over them. Some people leave the house and others enter, and the player has to keep track of the number of people in the house. Though Brain Training was developed in collaboration with a scientist (you guessed it — Dr Kawashima), there is to date little scientific evidence that it improves older people’s cognitive functions or prevents their decline. This is surprising for a game designed to do exactly that, and which has sold like hot cakes. Nintendo, however, was wise enough never to claim that it could prevent cognitive decline in older people. It certainly can do no harm to play games such as these on a regular basis, but I do object to the calculation of a mental age — this is just not possible on the basis of a few short tests on a games console. And it is irresponsible to tell someone who is 50 that they have a mental age of 63 without any explanation from an expert of what that means.
Is there any cognitive training that has been properly researched? In fact, cognitive training is nothing more than practising mental capacities such as memory, concentration, and thinking skills. People who have worked their whole lives with their brains because their profession required a lot of reading and reflection have a lower risk of developing Alzheimer’s. That in itself points to the positive effect of mental exercise in the long term.
The results of short-term exercises for older people have been studied in recent years. These exercises mainly consist of memory training, but differ between studies as each researcher invents their own variant. This makes it difficult to come to any general conclusions. Nevertheless, certain trends can be discerned. Researchers at the University of Southern California analysed the results of all published research into cognitive training for older people. It emerged that training can improve cognitive functions by 10 per cent. Given that the brain’s decline between 65 and 75 is on average 10 per cent, this is substantial. It doesn’t mean, however, that cognitive training can fully compensate for that decline. Cognitive training is often extremely specific, while the decline is across the board. So if you do a lot of Sudoku puzzkes, you become extremely good at Sudoku puzzles, but your brain hasn’t necessarily become sharper in other areas.
Nonetheless, there are indications that training based on lots of different exercises can improve cognitive skills generally. For example, a complex computer game can do this, as shown by American psychology professor Arthur Kramer and researcher Chandramallika Basak, both at the University of Illinois. They trained 20 older people in a real-time strategy game, Rise of Nations, and compared their performance in neuropsychological tests afterwards with that of 20 of their peers who had not been trained. In Rise of Nations, players have to run their own country: they build cities, help people to find work and food, maintain an army, and expand their territory. This makes a great demand on executive functions such as working memory, planning and calculating, maintaining oversight, and strategic thinking. In the end, the participants who had played the game (for an average of 23.5 hours) scored better on the tests than the control participants.
Though little research has been done in this area, physical changes in the brain after cognitive training have actually been measured. A German study found that nerve connections between the brain hemispheres were strengthened after six months of memory and speed-of-processing training in a group of people with an average age of 69. And researchers at Wake Forest University in North Carolina reported an increase in blood flow to the prefrontal cortex after eight weeks of cognitive training in a group of people aged around 70. They were compared with a group of the same age who attended interactive lectures on health and ageing. The increased blood flow to the prefrontal cortex after training was accompanied by improved concentration and ability to ignore distractions.
But cognitive training has an added benefit: older people actually feel better as a result. A Spanish study demonstrated that a group of seniors who had undergone cognitive training not only performed better in neuropsychological testing but also reported improved quality of life — a concept used in science to describe an individual’s general wellbeing and contentment with their situation. This may be the result of the satisfaction that comes from understanding things slightly faster or being able to recall slightly more. Or you may feel that you have more control over your cognitive abilities because you’ve worked on them.
In general, memory training has led to small improvements, especially in the skill that was practised the most in these studies: the ability to recall words and stories. But good training doesn’t just involve memorising. It also gives the participant useful strategies, such as the loci method mentioned earlier (in which you link names or items you have to remember with locations, for instance in and around the house). Another effective strategy is to focus more strongly on retrieving the information than on storing it. Imagine you want to memorise a piece of text for a speech. You can read it 20 times so you know it by heart, a method you’ll remember from your schooldays. But it’s more effective to read it three times and then try to recall what you can without consulting the written text. You may have to check a few times, but if you do, put the paper away again immediately afterwards. This is a more active way of learning that helps you to see a structure in the text, which is what aids memory. Research conducted at the Johns Hopkins Bloomberg School of Public Health in Baltimore among 1,401 older people who received memory training showed that they learned to make better use of memory strategies, thereby improving their memories. Follow-up research established that these improvements were maintained over a period of five years. Furthermore, the training had a positive effect on everyday functioning, including living independently, finding their way around, and remembering crucial things.
There are even more ways of enhancing learning ability — for instance, making crazy connections in order to remember things. Imagine you have to take your grandson to football practice on Beethoven Street. To remember that, you could picture Beethoven sitting at the piano, playing a sonata with a football balanced on his head while your grandson looks on in amazement. A good mood also helps with learning, as a study conducted by Professor Richard Ridderinkhof of the University of Amsterdam has shown. If you feel good, you absorb information better. But how do you achieve that? One way is to think about happy or amusing events in your life. Putting on your favourite music can help, too; or promising yourself a (healthy!) reward once you’ve completed the task.
How long do the effects of cognitive training last? Various studies have shown that this can be up to two years in the case of memory training, provided it was intensive: half an hour three times a week for at least three months. It is also advisable once training ends to continue to challenge yourself every day to remember things such as the names of people you meet, your shopping list, or what you had for dinner a couple of days ago. We don’t know if such exercises can (at least partially) slow the general decline in memory. More research is needed.
It is unlikely that training will completely halt cognitive decline in the long term, but the fact that your memory functions better if you exercise it is a valuable insight. Nor do we know if only the skill you actually exercise improves, or whether there is a more general effect. For example, you’ve learned a great number of word lists and improved your verbal memory. Does that mean you’ve only improved your ability to learn lists, or can you now remember where the soft drinks are in the supermarket? After all, the latter is a question of spatial memory, which you haven’t trained. To date, it would appear that exercises mainly improve the skill that has been trained.
But there are also studies demonstrating that older people can achieve better results on tests they have not been trained in by practising other, comparable skills. This seems mainly to apply to training that involves learning skills that are multifaceted and complex. Examples include learning a new language or a musical instrument. Making music is very good for cognitive function in both children and adults. A study of 70 healthy people between the ages of 60 and 83 with varying degrees of musical knowledge showed that those who regularly played an instrument scored better on a variety of neuropsychological tests. The longer a person had played (many had started when they were around ten years old), the better the scores. According to researcher Brenda Hanna-Pladdy of Emory University, ‘Since studying an instrument requires years of practice and learning, it may create alternate connections in the brain that could compensate for cognitive declines as we get older.’
Another suggestion for realistic training comes from neuropsychologists at Washington University, St Louis, who propose a course in birdwatching. There are two benefits here: first, your memory is trained by learning all the bird names and their physical features; and second, it is a social activity because you do it as part of a group. The physical exercise in the fresh air is a further benefit. Again, more research is needed to find out whether these activities lead to permanent improvements in mental abilities or a long-term delay in decline.
Finally, there’s this. A 102-year-old man from Belgium was invited in February 2012 to start at the local preschool the following term. It was, of course, an administrative error. But maybe, in the future, invitations like this will be sent, not for preschool but for a school for 70- to 80-year-olds. In fact, such schools already exist. The Seniors Academy in Groningen celebrated its 25th anniversary in 2011. Like similar institutions elsewhere, the Academy offers courses for seniors — with a minimum age of 50 — who want to develop their talents further. On the basis of the research we have looked at here, we can be sure that these types of courses are an excellent way to keep the mind sharp.
PHYSICAL EXERCISE
Last but not least, of all the ways to improve and protect our mental abilities, physical exercise has the strongest supporting evidence. As we saw earlier, the saying ‘a healthy mind in a healthy body’ has retained its validity over the centuries. But does this mean that promoting physical health through sport helps to stop the decline in our cognitive processes? And if so, how does it work?
Many older people get too little exercise. Individuals aged 55 and above are less active than the average person, and with age the difference continues to grow. According to the Department of Health, only one in four Australians over 75 is sufficiently active (as compared with 43 per cent of the adult population). The recommendation for people over 55 is half an hour of moderately intensive exercise on at least five days and preferably every day of the week. ‘Moderately intensive’ means that your breathing and heart rate increase, your body temperature rises, and you work up a sweat. It is indisputable that exercise improves health, but does it also benefit the brain?
Maaike Angevaren, a physiotherapist and researcher at the HU University of Applied Sciences Utrecht, contacted me in 2004. She had an ambitious goal: to write a general review of the effects of sport on older people’s mental abilities. She wanted to submit the article to the Cochrane Library, the database of the prestigious Cochrane Collaboration. The Collaboration is an independent, not-for-profit international network of medical researchers, and it publishes pioneering reviews of all kinds of treatments. These reviews collect and integrate all available data from high-quality studies to establish whether or not there is conclusive evidence about a specific treatment. I thought it an excellent idea to research the literature on the subject and to work with her team, whose members included a sports physiologist and a geriatrician.
Maaike was primarily interested in aerobic exercise, in which respiration and heart rate increase. Moderately intense activity improves heart and lung function, while a good supply of blood and oxygen is vital to the functioning of the brain. What’s more, a healthier heart means a smaller risk of a heart attack or brain haemorrhage. Maaike reviewed the literature and found 11 articles reporting on high-quality research into the effects of moderately intense physical exercise on cognitive function. In a typical example, subjects engaged in moderate-intensity workouts for half an hour three times a week for 12 weeks. They were compared with subjects in a control group who only did stretching exercises. Most of the studies found that the group doing the workouts showed an improvement in both heart/lung function and cognitive function, though not in all the neuropsychological tests administered in the study — it was primarily speed of processing and concentration that improved. Maaike herself observed that ‘the brain can be compared to a computer and the time it needs to boot up. The older the computer, the longer it takes to get going.’[4] Training can speed up information processing in the brain. Incidentally, the fact that both heart/lung function and cognitive function improved doesn’t mean that one leads to the other. Other factors that are influenced by this type of exercise may be involved, such as the release of growth factor into the blood, which has a beneficial effect on the brain. We’ll come back to this later.
Does all that huffing and puffing in the gym or the park have an effect on our brain tissue? Yes indeed — the brain gets bigger. And that can’t hurt, given the average amount (15 per cent) by which the brain shrinks between the ages of 30 and 90. In one study, MRI scans were performed to measure the volume of grey matter in the brains of 60 participants between the ages of 60 and 79 after they had taken part either in moderate-intensity or stretching exercises for six months. In the group who had engaged in moderate-intensity exercise — but not the other — the researchers observed an increase in grey and white matter in the front part of the brain. In another study, carried out at the University of Pittsburgh, Pennsylvania, 120 participants (with an average age of 67) were assigned to the same two groups, doing either moderate-intensity or stretching exercises. This time, their MRI scans were compared after a year, focusing on the hippocampus, which is essential to storing information in the memory. In the moderate-intensity group, the hippocampus had grown by 2 per cent, while that of the stretching group had shrunk by 1.5 per cent, the normal amount of shrinkage in people of that age. The researchers also looked at two other areas of the brain that were less affected by ageing, and found no differences. Thus, it is not true that every part of the brain is enhanced by moderately intense exercise, but the parts that decline as we grow older are. What makes these findings even more convincing is that memory performance improved as well: the greater the increase in grey matter in the hippocampus, the more memory improved.
The reason why exercise is so good for our cognitive function is clear: our grey cells get reinforcements. In fact, studies with large numbers of participants who exercise regularly show that this reduces the risk of Alzheimer’s, sometimes by as much as 50 per cent. The best situation is where the individual has always been physically active, but even people who start when they are 60 can benefit. And an extra advantage is that doing sufficient exercise lowers the risk of chronic disease: it has positive effects on those diagnosed with high blood pressure, high cholesterol and blood-sugar levels, and obesity.
So how does physical exercise get those grey cells working better? First, by increasing the flow of oxygen to the brain; and second, by activating growth factors. Moderate-intensity exercise stimulates the release of growth factors into the bloodstream and brain. One of the factors is IGF, which, as we have already seen, promotes the healing of damaged tissue in the brain, the growth of neurons, and the formation of new connections between them. Another substance that scientists are very interested in is BDNF, or brain-derived neuro-trophic factor, secreted by the brain to promote the growth of neurons. BDNF doesn’t work only in the brain but elsewhere in the body too, where it promotes the recovery and growth of nerve tissue. The Pittsburgh study that I referred to earlier, which demonstrated growth in the hippocampus after a year of moderate-intensity exercise, also measured the concentrations of BDNF in the participants’ blood. Higher concentrations of this factor were linked to an increased number of grey cells in the hippocampus. This finding correlates with results from animal research. In brief, the simplest way to keep your brain as healthy as possible is to walk, swim, cycle, or work out at a brisk pace for 30 minutes at least three times a week. That way, you don’t need to go to your doctor or pharmacist, but you still get the best medication through the miraculous way your body works.
There are forms of exercise that require less effort than sport but can still be valuable. This is especially relevant for older people who have difficulty walking. Tai chi, for instance, is a traditional Chinese martial art. In its ‘soft’ form, participants make slow, flowing movements that involve contracting and relaxing the muscles and consciously controlling breathing. Though there is no scientific evidence to back the ancient Chinese beliefs regarding meridians (energy pathways), there are reliable research results demonstrating the health benefits of the movements themselves. People can practise tai chi even after reaching an advanced age. Still, more research into its effects on the brain is needed.
The same applies to the claim of the Amsterdam psychologist Erik Scherder (who is also a professor of human-movement sciences in Groningen) that chewing is good for the brain. There are indications from research that chewing gum improves the flow of oxygen to the brain and can lead to improved cognitive skills. Since many older people have difficulty in chewing, they tend to be given food that doesn’t require much mastication. As a result, their ability to chew declines even further. Scherder thinks that good dental care for older people is essential, and that they should eat food that exercises the teeth and gums. And he thinks nursing homes should buy in large quantities of chewing gum!
IMPORTANT INSIGHTS