Exercise of any sort — including a brisk walk — plays a big part in cognitive and physical health as we get older, writes.
WE pretty much know that exercise is one of the magic bullets for healthy ageing, but how much are you regularly getting a week to keep your brain healthy?
And while walking to the shop, instead of driving, is always laudable, that doesn’t cut it with the ageing experts; your heart needs to be pounding, as well as your feet.
The amount of exercise needed to stave off certain aspects of cognitive decline was recently put at one hour, three times a week, over a six-month period, by researchers at the University of Miami’s Miller School of Medicine.
The systematic review looked at almost 5,000 studies, including 98 trials, and involving 11,000 participants of average age 73. The researchers concluded that those who put in that regimen over the six-month period, had a distinct cognitive advantage over those who did less exercise, or none at all.
Those two advantages were: Better processing speed, that is our ability to do simple or previously learned tasks; and improved executive function, our ability to plan, multi-task, and focus attention.
Both of those cognitive abilities are the first to go with the ageing process, say the researchers, which makes the association with exercise all the more exciting as a self-help preventative measure, since most of the participants had not exercised regularly at all, before joining any of the trials.
Almost 60% of the participants were healthy; 26% had mild cognitive impairment (MCI) and 14% had dementia. Aerobic exercise such as walking, biking and dancing; strength training; mind-body exercise like yoga and tai-chi — were all linked to the improved cognitive skills, in the healthy individuals and those with MCI, who have a higher predisposition to have dementia later.
The most common aerobic exercise was walking, which comes as good news to the Irish population. A study carried out for the national age-friendly organisation, Age & Opportunity, in conjunction with Sport Ireland, two years ago, found that walking is the most popular activity for the over-50s here, followed by swimming and golf.
However, despite regular associations in such research with lifestyle factors and cognitive decline prevention, last year, a report by the US-based non-profit organisation, the National Academies of Sciences, Engineering, and Medicine, cast doubt on the scientific rigour of the cause and effect.
It said there was only modest but inconclusive evidence available that increased physical activity could help prevent cognitive decline and dementia. They applied the same conclusion to two other brain health preventative strategies: Lowering hypertension and cognitive training.
That does not mean we should give up on those activities, of course, while we await further clinical trials to conclusively support those interventions. “There is good cause for hope that in the next several years much more will be known about how to prevent cognitive decline and dementia, as more clinical trial results become available and more evidence emerges,” states the report.
Geriatrician and chair in clinical gerontology at UCC, professor Willie Molloy, has no doubt, after over three decades of research into cognitive decline and dementia, that exercise of any sort, that gets you physically challenged, is a necessary preventative measure we need to take for cognitive health as we age. It is one of three big lifestyle influences he identifies as major players in keeping dementia and cognitive decline from our door.
“Those who are active take twice as long to convert into dementia than others. Those who are regularly inactive take five years, and those who are active ten years; that’s exercise that gets your heart rate up"
We also need to enjoy it, so that it becomes a routine. “Get a good pair of walking shoes and stretch before you start — I don’t think the type of exercise matters. I myself walk on beaches regularly because the surface is soft,” he says.
The consultant geriatrician, who also works clinically with patients at Cork’s Mercy Hospital and St Finbarr’s Hospital,
is also convinced that if you want to stave off dementia you need to control your blood pressure. When we think of high blood pressure, we may be more inclined to associate it with higher risks of cardiovascular and kidney disease, but “the brain can’t stand hypertension”, says Molloy.
“We know that those aged over 50 who have hypertension — high blood pressure — are four times more likely to have dementia in their 70s.” He bluntly warns: “If you want to keep your marbles, keep your BP down.”
The importance of a healthy diet is the third major influencer he mentions: “Don’t get fat around your middle — it sets up an inflammatory response in the body and this leads on to chronic inflammation in the brain. A total of 80% of chronic diseases are caused by a diet too rich in salt, fat, and sugar.” Processed food, in other words.
While the regular flow of outcomes from current research only give us guidelines about possible preventative cognitive decline measures we can take, ultimately it’s up to us to adopt a healthy lifestyle.