Although there might be a general relationship between our age and how efficient our brains are, what seems to matter more than our actual age is how healthy our brain is. So what can we do help our brain remain as healthy as possible as we get older? Exercise, particularly cardiovascular exercise, is one way.
Common Stereotypes of Ageing
A typical stereotype of getting old is of people experiencing more and more so-called ‘senior moments’, such as forgetting simple things and generally being less ‘with it’ mentally. Now, whether this is an accurate view or not, research shows that believing – or even simply hearing – negative views of old age can actually be harmful.
For instance, research has shown that older adults who have been first shown a negative stereotype of ageing (e.g., cranky, forgetful, etc.) then perform worse on memory tests than those who were shown more positive views of older age (e.g., wise, experienced, etc.) [1]. More worryingly, younger people who hold negative attitudes about being old are at a greater risk of having a heart attack or stroke when they get older [2].
But it’s not just a question of trying to think more positively about the ageing process. Whilst it is helpful to take a more optimistic view of ageing, scientific research also shows that there are steps we can take to preserve our mental abilities throughout our lives.
What changes occur as we get older?
There isn’t one single way to describe the ‘normal’ changes in our brains and mental abilities as we get older because people differ widely and not everyone experiences these changes at the same pace.
We use our brain in several ways. Our ‘fluid intelligence’ is our ability to think logically and solve new problems and we can start to lose this ability as we get older. Our ‘processing speed’ also tends to slow down, so it might take us longer to put a name to a face. But other things hardly change at all: our ability to do maths and calculations remain pretty much the same across our lifetime and our verbal skills stay the same or even improve as we get older.
The brain contains both ‘grey’ and ‘white’ matter and we typically lose some of both as we get older. The good news is that these losses don’t occur in all parts of the brain and the rate at which the brain loses volume varies widely across individuals.
Even better news – and contrary to popular belief – is the discovery that we don’t start out with all our brain cells at birth and then gradually lose them during our lifetime. We now know that in at least one area of the brain – the hippocampus (which is important for learning and memory) – healthy brains can grow new cells in a process called neurogenesis.
To cut a long story short, it is not possible to determine how old someone is simply by looking at the size of their brain on a scan or how well they do on a memory test. For example, in 2008 scientists found that a 113 year old woman was able to do mental tasks with above average speed and accuracy for a 60-75 year old and her brain was almost the same size as someone of 30 [3].
Effects of exercise on our brain health
As we get older we tend to get slower at things like word-finding: for instance, you see a picture of a celebrity, but it seems to take you ages to find their name in your memory. The good news is that research is showing that working to improve our cardiovascular (heart) health through the amount of exercise we do can help prevent loss of grey-matter in the brain and improve our ability to remember things.
Using brain scans, scientists found that older adults with good cardiovascular health lost less grey-matter than those with poor heart health when their brains were scanned again nine years later (mostly in parts of the brain important for memory and learning). Two things are worth mentioning about this study; firstly, the effect was only seen in adults who walked an average of 6-9 miles per week (that’s about one mile a day) and secondly, adults with better heart health were also less likely to develop dementia [4]. This study does have some limitations: it relied on participants being honest about how much walking they did and didn’t explore what other exercise they did. However, it is a positive sign that being physically healthy can perhaps help us be mentally healthier.
So if having a healthy heart can help prevent loss of grey-matter in certain parts of the brain, it seems likely that this will also help you to use those parts of the brain. The research seems to bear this out, showing that adults who have better cardiovascular health perform better on difficult mental tasks [4].
So, cardiovascular health, which can be improved by aerobic exercise, seems to help slow down the normal losses in brain cells we might expect as we got older. This then seems to help older people do better on cognitive tasks, like memory tests. We don’t yet know how this works – heart health and exercise might stop us losing brain cells, or help us grow new ones, or both. We need more research before we can be sure.
How much and what type of exercise should I be doing for my brain health?
In a 2011 study, people attended either aerobics classes or stretching/toning classes for one year. After one year, brain cells in the hippocampus (which helps learning and memory) had decreased as would be expected with age in the stretching class group, but had increased in adults who did the aerobics classes. The aerobics group also did better on various memory tasks than the stretching group [5].
So what the research seems to show is that you are likely to get the most benefits to your brain health if you do regular cardiovascular exercise. Cardiovascular exercise is any activity that gets your heart rate up enough to huff and puff and so you feel a bit sweaty. Hiking, aerobics classes, tennis and even walking the dog briskly all count. Many people say that they feel in a better mood and more motivated when doing group exercise than they do when they exercise alone, so you could consider joining a local walking group or exercise class.
And remember it is never too late to start! Guidelines for exercise vary depending on age, but sites such as the UK’s NHS website has lots more information. People with health complications should check with their doctor that they are fit to do aerobic type exercise. Speaking with a qualified personal trainer will help people get ideas for healthy but challenging exercise routines.
Summary
New research is showing a more positive view of ageing, whereby brain health matters more than our actual age. Our brains have an amazing ability to compensate for the natural effects of ageing and even grow new brain cells in some parts of the brain throughout our life. We can help our brains be better able to adapt to the changes that occur as we get older by working to improve our heart health through cardiovascular exercise and activities.
This article takes a positive view of ageing and how to look after our brain health. However, some people do suffer from a genuine problem, and start to forget things in a way which can be confusing and frightening. If you are concerned about yourself, or someone else, speak to your doctor for more information and advice.
This article was first published online here.
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