Maths and reading delay cognitive decline

More great new research now, which has found that people who use maths or reading skills regularly do not experience age-driven decline in cognitive skills. Previously, we thought we were all intellectually going downhill from about 40. But this was based on comparing different groups of people at different ages, which may have been misleading. The new study has followed the same cohort of people but over a period of time, and it suggests that it’s a case of use it, or lose it: cognitively stretch yourself and you’ll maintain your brain power into older age. The findings are published in Science Advances, and Barbara Sahakian - a professor of clinical neuropsychology at the University of Cambridge - came to meet Chris Smith at Queens’ College to take me through what the results appear to show…

Barbara - Basically, what it's trying to look at is the idea that if you stay challenged in your workplace and if you start off with a good education, you will not cognitively decline as fast as other people in terms of your maths ability, and also in terms of your literacy.

Chris - What were our prevailing thoughts in that direction? Because I've seen mixed opinions about this. Some people saying, “You do the Telegraph cryptic crossword every day and this keeps you mentally agile.” Other people turn around and say, “You do that crossword because you can and it's a sort of selection bias.” What is the thinking? Do brain games keep us fitter, did we think, or did we just not believe that was true?

Barbara - It has to be something challenging driving the circuitry in the brain and that really has to do with learning new things, so if you're doing something that's simple for you, like a daily crossword that maybe you're very familiar with and you don't challenge yourself by going to more difficult levels, it really won't help you in that way.

Chris - Are you of the opinion though, before we come on to what this new paper has done and found, that doing that kind of ‘keep my brain active’ keeps me in a better cognitive state? Are you of the mindset that that is true or do you think that that's a bit of an old wives tale?

Barbara - No, it's absolutely true, there's plenty of evidence to show that if you do keep yourself cognitively active you will have a better cognitive outcome and you're less likely to decline with ageing.

Chris - What did this new paper add then? What have they done?

Barbara - Well, part of what they've done which is very interesting is, a lot of our data has been cross-sectional and here they've taken a longitudinal approach, so they've actually looked at the same people over time and that helps a lot. The sample size was not that large; it was about 2,500 people, and also the tests they used were quite challenging within the workplace, interesting tests of mathematics and literacy.

Chris - When you say ‘cross-sectional’ versus ‘longitudinal’, so in other words, rather than take one group of people of a certain age, compare them with another group of people of a certain age, and then see who's got the best cognitive function, you're saying we take one big group of people and they just followed them up over time?

Barbara - That's it and that way you get more accurate data on what's happening.

Chris - Who were the people that were being followed and how did that affect - if it did - the outcomes?

Barbara - Well, they came from a German sample but the ones that they were specifically interested in because they wanted measures of how they were using these skills within their workplace were all employed so that's also quite an interesting feature because a lot of the studies that have looked at use it or lose it or keeping cognitively active have been with older age people say 60 or above so this is interesting because they were looking at people who were being employed.

Chris - Can we generalise then, or can you give us some sort of overview findings from the paper? What age do things continue to get better until and then what happens? Because I've been brainwashed into thinking that once you go beyond 40 it's all over. I'm now beyond 50. Is it all over or am I still in good shape?

Barbara - Well, in this study the key points seem to be, early 40s and mid-40s for the literacy and mathematics.

Chris - What? That you peak?

Barbara - Yeah where you start to decline.

Chris - Oh dear.

Barbara - But actually with psychomotor slowing and other functions it could be earlier. There's lots of evidence that it’s your 20s and 30s when you're at your peak for most different kinds of cognitive functions, and then you start to decline. But in this group, especially in the high functioning group, which were in white-collar jobs and had a good level of education, they stayed functioning better for longer in terms of literacy and mathematics. But what I would say is that experience counts for a lot. Experience is basically pattern recognition. When you are in your workplace and you suddenly have to contend with a problem, you might think this problem looks very similar to one I've done before and when I did this it actually was a good solution to this problem, so I'll try it again. Or you might be able to anticipate, if you're in some kind of a white-collar job or some other job, anticipate that this could be a problem if this happens, so I'm going to make sure we avoid this happening so that we don't have any problems. That's experience. Within the workplace experience actually counts for a lot as well.

Chris - In summary then you're saying that although our abilities might peak in our mid-40s, if we give ourselves a good cognitive workout regularly the slope down thereafter doesn't have to be a steep one. It can be preserved for much longer.

Barbara - Absolutely. So the idea is you just keep challenging yourself cognitively and you will have a better outcome in terms of ageing and your cognitive function. The other thing is that cognitive reserve, which is kind of a combination of your intelligence level and your education level, if you keep learning throughout life what you find is that if anything does happen to you, if you're unlucky and you have a traumatic brain injury or if you develop a neurodegenerative condition like Alzheimer's disease, you will actually have a better outcome than most people. It's less likely to impact you in a negative way.