Keeping mentally active preserves memory, but is there a later cost?


It’s Adult Learners Week from the 1st to 8th September. This is part of the International Festival of Adult Learning that began in the UK back in 1992. Here in Perth, the ECU is supporting the initiative with many events and activities being put on to promote the benefits of learning either at home, in the workplace, or in the community.

During the week, a variety of different topics are presented each day ranging from Tai Chi to word processing, personal finance and poetry.
I was listening to a local radio segment where a lady from ECU was espousing the overall benefits for adults to continue to learn throughout our lives. She mentioned it was fun, how stimulating it was to be learning something new and different, and how good it was for one’s overall well being. What she didn’t say however, was just how much benefit we give our brain by undertaking to learn new skills.

Coincidentally this week, a study was published in Neurology confirming the benefit of mentally stimulating activities to boost our cognitive reserve and help defer or delay the onset of cognitive decline and dementia.

Dr Wilson from the Rush University of the Medical Center in Chicago reported that by being mentally engaged in activities such as reading, listening to the radio, doing crossword puzzles, going to museums, playing games or watching TV we make a significant difference to maintaining our cognitive performance.

This 12-year long study followed 1157 subjects (without dementia) aged 65 years or older. They were asked questions about their level of participation in a variety of mental activities. The subjects were awarded points for participation on a cognitive activity scale. The higher the number of points achieved reflected the higher the level of participation recorded. Over the following six years the researchers found that for each additional point on the scale, the rate of cognitive decline was reduced by 52%.

The twist in the findings.

However there was an unexpected result in the findings. And this was that those who engaged in the most cognitive activities and who built up the most cognitive reserve, who then subsequently went on to develop dementia, then went into a much faster rate of mental decline than those who had not been so mentally active. And this was by an increase of 42% per point on the cognitive activity scale.

What this implied was that by engaging in a variety of mentally stimulating activities and thus building up cognitive reserve, people were able to stave off the symptoms of Alzheimer’s disease or dementia. However, when symptoms eventually did present, the rate of mental decline and death was then much faster.

Why should this be?

One explanation put forward is that by building up a bigger cognitive reserve, people who may already have the plaques and tangles associated with Alzheimer’s disease are still able to live normally without any apparent sign of cognitive impairment.

This should not come as any particular surprise given the findings from the Nun Study. Back in 1986 a longitudinal study involving 678 Catholic Nuns aged 75 to 106 years began. In this remarkable study the Nuns agreed to donate their brains for the study research after they died. Many of the nuns were functioning very normally on mental testing and living full and varied lives, yet after death on autopsy, some were found to have brains riddled with Alzheimer’s disease that had not been apparent clinically.

In 2006 a meta-review of research into brain reserve was undertaken by the UNSW where they looked at the integrated data from 22 studies from around the world involving 29,000 people. The conclusion was that engaging in complex mental activities over the course of a lifetime can reduce your relative risk of developing dementia by 46% . All mentally stimulating mental activities were found to have a positive protective effect and that it was never too late to start engaging in building brain reserve.

So it seems that there is clear benefit of delaying the initial onset of cognitive decline through being involved in mentally stimulating activities. However there is a potential cost, that if symptoms of dementia subsequently develop then this is likely to be followed by a more rapid rate of mental decline.

There has already been discussion of the need to try to delay the onset of dementia through environmental and lifestyle choices because of the huge cost burden to the existing health system and society. Even a delay of 5 to 10 years of onset of symptoms will produce significant cost savings.

Given the choice, I think I would prefer to live as well as I can, for as long as I can by remaining mentally engaged in lots of different activities. If dementia subsequently rears its ugly head, then I would prefer to go quickly. Far better than a long tortuous drawn out decline which is also far worse for one’s loved ones and family.

What are your thoughts?

References:
R.S. Wilson, L.L. Barnes, N.T. Aggarwal, P.A.Boyle, L.E.Herbert, C.F.Mendes de Leon, and D.A. Evans. Cognitive activity and the cognitive morbidity of Alzheimer’s disease. Neurology,2010; DOI: 10.1212/WNL.0b013e3181f25b5e

University of New South Wales (2006, January 31). Use Your Brain, Halve Your Risk Of Dementia.

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