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27 Jun 2016

Six lifestyle choices that can cut your risk of dementia

I attended an interesting lecture today titled “Can Five a Day Keep Dementia Away”? The speaker was Professor John Gallacher who is in charge of the UK’s Dementias Platform programme which is a £53 million collaboration between universities and drug companies to find treatments for dementia. Part of their job is to study lifestyle changes that can delay the onset of dementia.

What surprised me was not that there were things I could be doing to reduce my dementia risk. It was the scale of the reduction, which could be 60% or more[1]. It starts to make dementia look more of a lifestyle disease like heart-attacks and diabetes.

So here’s your anti-dementia prescription:

  1. Get regular exercise
  2. Stop smoking
  3. Eat a healthy diet
  4. Maintain a healthy weight
  5. Maintain healthy blood pressure
  6. Keep alcohol intake moderate

Professor Gallacher drew on a number of studies. Some tracked participants’ lifestyles over at least 20 years to see who developed cognitive problems.  Other shorter studies put participants on different regimes eg improved diet/exercise and then measured specific outcomes like memory or executive function.

What researchers found was that doing any one of the six reduces your risk, but doing more is better. I’d like to tell you how much you could benefit by doing all the recommendations but as the number of people who follow such a lifestyle is so vanishingly small, they couldn’t get any robust data for this!

Gallacher emphasised that more studies are needed to be able to give clearer recommendations, but the results so far make sense – anything that protects against lifestyle diseases like stroke, diabetes and heart disease also protects your brain.

Exercise comes up trumps, not just for dementia. It seems to one of the most important things you can do to reduce your risk of dying. A study[2] published in 2011 tackled the question of how much exercise you need, with a group of over 400,000 people who were tracked for eight years: 15 minutes per day conferred a 14% reduced risk of dying (over the group who did practically nothing). Every extra 15 minutes added more protection until it topped out at about 90 minutes per day.  The general recommendation[3] is something like half an hour of aerobic exercise five days a week with some strength exercises a couple of days.

I should just add that for one of the UK studies they did try to measure what motivated people to take up exercise. And the factor that had almost no effect whatsoever was knowing the health benefits! Far more likely to help was finding an exercise you enjoyed, doing it with friends and embedding it as a habit.

As far as nutrition goes, there is now a MIND diet for eager beavers to try. It’s pretty similar to the Mediterranean diet with an emphasis on brain friendly foods like fish, dark leafy greens and berries. It saw big reductions in risk, up to 50%, for people following the diet most closely – but of course that’s just one study and it’s early days for research on specific dementia diets.  There’s a good article on it at http://www.quickanddirtytips.com/health-fitness/prevention/how-does-the-mind-diet-protect-against-alzheimers.

There were some other lifestyle factors that Gallacher mentioned that were less within our control. Suffering from depression or anxiety was a risk factor for dementia. Higher education levels were protective. Diabetes is linked to dementia, but obviously following the advice above will also reduce diabetes risk.

One member of the audience who had not gone far with education in her youth asked if she could make it up now. The advice was that learning at any age is good but research hasn’t yet shown if it reduces the pathology like early education does or if it just helps you make more efficient use of your brain as it is. Either way lifelong learning makes sense.

Interestingly a talk by neuroscientist Richard Restak to the New York Academy of Sciences noted that a large part of the brain is devoted to controlling the fine motor skills of the hands. So to stimulate the brain he recommended learning new skills like playing an instrument, doing carpentry, craftwork etc which used the hands. Note the emphasis on new skills – the most important thing seems to be challenging the brain, so once you become competent you need to find a new skill to master. Doing the cryptic crossword every morning for the rest of your life wouldn’t qualify!

A number of online brain training websites are taking off, as fears about dementia rise. Research is trying to test whether the sorts of games these websites offer have a lasting impact on the brain. I note that one of these sites, Lumosity, has been ordered by US federal investigators to reimburse customers to the tune of $2million because it made claims that there wasn’t research to back. From the data I’ve seen, I think we’d all be better off getting our diets and exercise up to scratch before we started looking to these websites for help.

Sadly the Ministry of Health expects the number of New Zealanders with dementia to increase 60% by 2026, to about 78,000. That’s a lot of families and communities suffering with a dreadful disease. And the cost of dementia to New Zealand in 2011 was estimated to be $954.8 million and is steadily rising.

Professor Gallacher’s research is great news for us individually because it stops dementia seeming such a random bullet. But not such great news for us collectively, because getting a population to make these changes is something we’ve been spectacularly unsuccessful at. But we have to try because the burden of care will be frightening if we don’t.

Finally, for a world-wide look at the disease burden of dementia, here is a map produced by the talented Oxford geographers Professor Danny Dorling and Dr Benjamin Hennig. They specialise in creating maps of the world that aren’t all about land area, to help us see the world in new ways (their website www.worldmapper.org is worth a look). This one shows countries sized according to the number of people who die from dementia each year.

dementia map


 

© Copyright Sasi Group (University of Sheffield) and Mark Newman (University of Michigan)

(North America/Canada – blue, Europe – purple, India – yellow, China and South Korea – bright green, Japan – bright purple)

 

[1] Excluding the small percentage of the population with a genetic predisposition.

[2] Minimum amount of physical activity for reduced mortality and extended life expectancy: a prospective cohort study, the Lancet vol 378, No. 9798, p 1244-1253, 1 October 2011

[3] American Council on Exercise promotes 150 minutes per week. The UK’s National Health Service and New Zealand’s Ministry of Health recommend 150 minutes per week moderate exercise (eg fast walking) or 75 minutes vigorous (eg running), plus some strength exercises 2 or more days.