Review highlights the value of exercise for the prevention of dementia and brain ageing

I’ve written before that my experience is that individuals believe their physical health and wellbeing is generally much more controllable than their mental function. Many believe, for example, that lifestyle modification can keep, say, heart disease or type 2 diabetes at bay, but that their risk of dementia is essentially in the lap of the gods.

While the brain is perhaps a special organ, it’s an organ nonetheless. It is therefore susceptible to a range of factors that can affect it’s functioning, including in later life. One factor that has received considerable attention here in recent years is exercise. This week saw the publication of a review study in the Mayo Clinic Proceedings which summarises the state of the evidence here so far [1].

The review highlights the evidence which links exercise in midlife with a reduce risk of dementia and ‘mild cognitive impairment’. These studies are interesting, but actually don’t tell us that exercise is beneficial for brain function – only that these two things are associated.

The review also, though, looks at trials where individuals have been put on an exercise regime and the effect of this monitored. The evidence shows that exercise does indeed have the capacity to improve ‘cognitive scores’ (brain function).

Some of these studies have shown structural changes in the brain as a result of exercise, including enlargement of the hippocampus (a part of the brain concerned with memory) and a reduction in the loss of grey matter.

The mechanisms behind how exercise helps to preserve or even improve brain function are complex. One potential mechanism concerns the stimulation of what are known as ‘brain derived neurotropic factors’ which, among other things, facilitate brain cell communication. Exercise is also known to stimulate blood supply to the brain.

Exercise also likely has the capacity to reduce the risk of ‘cerebrovascular disease’. Caused by narrowing in the vessels supplying blood to the brain, this can lead to small (often symptomless) ‘infarcts’ (death of brain) tissue, and eventually lead to what is sometimes termed ‘multi-infarct dementia’.

My belief is that walking represents possibly the best form of ‘aerobic’ exercise for older individuals, for a variety of reasons, some of which I share here. Nothing more strenuous and difficult than walking has been associated with improved brain function in later life (see here), and has even been shown to improve the structure and function of the brain (see here).


1. Ahlskog JE, et al. Physical exercise as a preventive or disease-modifying treatment of dementia and brain aging. Mayo Clinic Proceedings 2011;86(9):876-884

11 Responses to Review highlights the value of exercise for the prevention of dementia and brain ageing

  1. Albedo 9 September 2011 at 3:36 pm #

    It’s difficult to believe that sport helps the cognitive function when you watch interviews of soccer players :p

  2. Katharine Locke 9 September 2011 at 7:08 pm #

    I wonder if there is any evidence for yoga eg inverted poses like shoulder stand and headstand protecting against yoga. They also stimulate oxygen delivery to the brain

    Katharine Locke
    Medical Herbalist

  3. Katharine Locke 9 September 2011 at 7:11 pm #

    I meant protecting against dementia! Tired brain and on my way home from visiting my mother who has dementia.

  4. audrey wickham 9 September 2011 at 10:36 pm #

    I wonder if the “What you don’t use you lose” thinking might not help. Churchill, Harold Wilson and Mrs. Thatcher used their brains most of their lives and suffered from some form of dementia once they stopped using them to the same extent after retirement.

    I have thought for some time that our memories are the same all our lives – it is just when we start to get old our friends and relatives think it has changed because of our age. I sat on the steps outside my home many times because I forgot my house keys. Left things on buses and flooded the kitchen/bathroom – no-one thought that was dementia – just that I was stupid! Not stupid, just had my mind on other things. I have had students in the house who most days came back within minutes because they had forgotten something important for their lectures.

    Please do tell – now that we are living longer which ages are classed as “midlife”?

  5. haider 10 September 2011 at 2:14 am #

    I thought the article was about mental execise.

  6. Deborah Booth 10 September 2011 at 1:13 pm #

    I have practised Yoga for much of my adult life and a form of Iyengar Yoga for the past 15 years, and in the latter I have done a headstand at every session, the thinking being that it increases blood supply to the brain, as well as being a wonderful meditative experience.
    What do you think John?

  7. Deborah Booth 10 September 2011 at 1:19 pm #

    Oh, and I too would like to know what constitutes Mid Life!! I consider myself at 61 to be middle aged.

  8. Chris 10 September 2011 at 5:44 pm #

    A few weeks ago I encountered the concept of ‘Earthing’ and I concede I was sceptical. Very sceptical.

    The concept of ‘Earthing’ is that the body needs, and is healthier for, the presence of a complete conductive path with the Earth. It’s a bit like electrical appliances are safer for having a connection to ‘Earth’ in case of a short circuit or malfunction. Advocates of biological ‘earthing’ posit that having a connection to earth or to ground is crucial to health, and the presence and concentration of nerve endings on the soles of the feet is taken to have functional purpose in respect of this. Initially I thought, “Yeah, right!”

    Actually us modern humans do not spend a lot of time with a good conductive connection to ground. An indication of this is that sometimes we become statically charged and get a shock when we touch something that is grounded. But if you think about it much of life has evolved with a strong and permanent conductive connection to ground. Few species get to live in a way that is consistently insulated from ground. Now the biochemistry that makes life possible is based upon carbon chemistry and the marvel of carbon chemistry seems to lie with the energetics inherent in the affiliations carbon forms with other elements. Those affiliations can store or release energy that is tied up in the bonds carbon forms with other elements such as hydrogen or oxygen. It’s not my forte but this has to do with electron-volts, does it?

    After a little reflection I’ve had to reconsider my initial willingness to dismiss ‘earthing’ out of hand. The potential benefits do not seem so implausible after all. I’d like to know more and I’ve added the title I chanced upon to my intended reading list. Incidentally, reader reviews on Amazon include positive remarks about positive results. More recently, I learn that at least one member of the network of THINCS harbours enthusiasm for the potential of earthing.

    To come to the point, John, I’d be in no doubt that walking is beneficial, but a recent encounter now leaves me wondering if there is added potential, say, in walking barefoot. There are occasions, most actually(!), when this is not really practicable, and you don’t have to walk to experience grounding – you could be at rest- but footwear and the buildings we spend much time in would limit the opportunities for being properly grounded.

    What do you reckon, is earthing bunkum? Could a reliable conductive connection to ground be promotional of greater well-being just as some regular low stress exercise can be?

    Something I figure is that if earthing is not actually beneficial it is unlikely to be harmful (since ‘life’ has a strong and demonstrable pre-eminence firmly rooted with connections to ground) which is far better than one can say for statin therapy or, just possibly, other cholesterol lowering policies.

    Link to the book at Amazon: ‘Earthing: The Most Important Health Discovery Ever? [Paperback]’

    Dr Stephen Sinatra discusses ‘earthing’ – part 1, available at

  9. helen 11 September 2011 at 2:09 am #

    Audrey couldn’t agree more – no one bats an eyelid if a 20 year old forgets something but be over 60 and it is a sign of dementia. I get really annoyed about stupid generalisations especially when they come in the form of “health” information. And if everyone doesen’t know it 70 is now the new middle age!!! It should be 100 but most people find that too much of a mind stretch. Time everyone especially the media and medical profession just stopped being so ageist and judgemental, don’t you think?

  10. Sam 13 September 2011 at 3:13 pm #

    Dr Briffa,

    In regards to aging, what do you think of the amount of AGES in cooked animal products compared to grains, potatoes, fruits and veg.

    It seems animal products are all very higher, especially the more protein dense..which leads to ageing.

    Therefore a near or complete vegan diet combined with exercise would be the most beneficial to prevent dementia and brain ageing?

  11. Jim 14 September 2011 at 6:31 pm #

    Have you read “Spark” by John Ratey? This book is about his experiences and views of exercise and the brain. He references brain derived neurotrophic factors a fair amount and equates them to “miracle-gro” for the brain. He firmly believes that exercise should be an integral part of treatment for neurologically related problems – anxiety, ADHD, depression etc… He even recounts the use of exercise in a particular school district demonstrating test score improvement.

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