‘Mild cognitive impairment’ describes a state characterised by impair brain function that is not severe enough to be classified as dementia. Memory issues are a common feature of mild cognitive impairment. It is believed that much of memory function is the domain ofpart of the brain known as the hippocampus (there are two of these, one on each side of the brain).
A study published this week found that a 6-month programme of aerobic exercise (two, hour-long walks each week) in women aged 70-80 with mild cognitive impairment led toenlargement of the hippocampi [1]. Resistance training did not have this effect. Unfortunately, there was evidence that this did not necessarily translate into improved brain performance. In fact, enlargement of the size of the hippocampal size was found to be associated with worse performance on some measures of memory and learning.
However, this is one study, and it’s worth putting it in the context of other research. In a previous study, older adults took three, 40-minute walks each week. Others engaged in ‘stretching and toning’ activities [2]. All study subjects were assessed in a range of ways including memory, levels of ‘brain derived neurotropic factor’ (a substance that stimulates new brain cell development and brain cell communication), as well as the size of a part of the brain known as the hippocampus (which is involved in memory function). Compared to the ‘control’ group, those who engaged in regular walking experienced an increase in volume of the hippocampi, but also saw improvements in memory function. Levels ofbrain derived neurotropic factor rose, too.
In yet another study, a group of sedentary individuals aged 59 – 80 had their brain function assessed [3]. As with the previous study, individuals engaged in either walking (40 minutes, three times a week) or stretching and toning exercises. Study subjects were reassessed after 6 and 12 months.
Assessment took more than one form. One test employed was ‘functional magnetic resonance imaging’ (fMRI). This tests brain activity. One part of the brain the researchers were particularly interested in is known as the ‘default mode network’. This part of the brain in most active when individuals are inwardly focused, but becomes naturally more quiet once someone has to focus on their external environment for some reason.
At the end of the study (12 months), compared to those who had been stretching and toning, those on the walking regime saw, on average, an increase in the default mode network connectivity. They also saw increased activity in another part of the brain (known as the ‘fronto-executive network’) which assists individuals perform complex tasks.
Crucially, though, the walkers did on a range of cognitive tests too, especially those that are sometimes referred to as ‘executive control tasks’ (e.g. planning, scheduling, dealing with ambiguity and multi-tasking). It is these skills, by the way, that do tend to suffer when we age.
As a whole, the evidence suggests the regular walking is good for brain function in adults. Some of the benefits may come from the activity itself. However, I wonder whether at least some of the effect is as a result of factors related to the activity (such as being in natural sunlight).
Whatever the precise mechanism, I think getting out for walks (for those who are able) represents a very doable and sustainable activity that stands to enhance mental functioning and quality of life. No special equipment required. And it’s free, too.
References:
1. ten Brinke LF, et al. Aerobic exercise increases hippocampal volume in older women with probable mild cognitive impairment: a 6-month randomised controlled trial. British Journal of Sports Medicine, 2014; DOI: 10.1136/bjsports-2013-093184
2. Erickson KI, et al. Exercise training increases size of hippocampus and improves memory. Proc Natl Acad Sci USA. 2011;108(7):3017-22
3. Voss MW, et al. Plasticity of brain networks in a randomized intervention trial of exercise training in older adults. Frontier in Aging Neuroscience doi: 10.3389/fnagi.2010.00032
Does it have to be walking..? I can’t walk far but I can cycle..
HH
Just a very brief response before I unpeel my elderly body from the sofa and go for a long walk.
Perhaps I could just thank you for posting this article and highlighting the health benefits of normality. Good air, water, food, shelter and mobility tend to be overlooked because they are essential to increase the chances of good health and yet they are so normal and therefore non-commercial.
The problem with being normal and therefore non-controversial is that they are taken for granted, then ignored if not denigrated in favour of more exotic and egotistical activities.
Perhaps we should all champion them, celebrate them, nag on about them because the marketing budgets for ‘cures’ are ludicrous.
So thank you very much.
I will not be doing the marathon tomorrow but I might go for a contemplative or, maybe, a social walk.
Kindest
Interesting that regular walking is that good. I myself like do take long walks a few times a week and I find it to be very meditative. My mind drifts in different directions and gets interrupted by things I see and hear during my walk. It’s nice to see birds, squirrels and other animals and I feel very rejuvenated afterwards.
Perhaps it’s the meditative effect that makes walking so good.
Walking had been a regular part of my life until lately when previously I had been fit and alert (I am 83)but over the past two years I have suffered from depleted energy when one squanders considerable thought processing trying to avoid physical activity. One wonders whether the plummeting of energy and the feeling of both mental and physical lethargy precedes mental decline. I find that with advancing age diet becomes more critical and one that consists principally of uncooked or non-processed foods seems almost imperative as digestion appears to be crucial to one’s feelings of well-being. I am currently experimenting but as yet have not found the correct balance of foods. Occasionally I will try something like taking more fruit which is followed by feeling more energised and this will last for about five days when one’s energy plummets and one returns to feeling lethargic both mentally and physically.
I am finding that while typing another word arises on the page different to the one I was typing. In the en-suite there is a linen basket for dirty laundry near to the toilet and twice lately I lifted the lid of the toilet seat and threw in my dirty laundry! Next to the en suite there is a cloakroom and this evening I entered it, locked the door, only to discover that I had entered the wrong place in mistake of the en suite! Three months ago on retiring, I switched off the bedroom light and swung on to side of the bed only to find myself collapsing on the floor and much to my wife’s consternation; in all my years I have never missed the bed on climbing into it. I sure hope those symptoms do not get worse!
I do similar things, Robert and I am in my fifties! I think it when one’s mind is elsewhere, so I now try to practice mindfulness.
Dear Mr Robert Park,
Isn’t it good to know from snowmoonelk, that we are not the only ones whose packed-with-knowledge and experience-minds are sometimes so distracting that we occasionally discover novel ways to enjoy our ‘Age of Serenity’?
I wonder if, as you mention, possible digestive weaknesses, you may have considered consulting a naturopath or a holistic doctor for an assessment?
It can be pricey but I found it worthwhile because it is beyond the interest level of NHS GPs. I was tested by The Doctors Laboratory in London but had to be referred there by a private doctor. Both my mother’s and my digestive systems were in a bad way thanks largely to long term use of unsuitable and ineffectual prescribed medicines.
Some would claim that, with advancing years, our digestive systems may not be as efficient as they once were. So maybe something worth thinking about and investigating.
Perhaps the most important thing though is that whatever we decide, it’s important to slow down and smell the coffee and enjoy our glorious spring.
Please accept my kind regards.
It would be nice to find out that it was the exposure to natural sunlight that was the most beneficial. You can get that lying down. =)