Brain health and poverty: Dr Etu Ma’u

Q. Why is poverty a risk factor for dementia?

A. What we first have to remember is that while we see dementia as a disease of older people, it’s actually the end result of brain changes that have accumulated over the course of a lifetime. It’s the cumulative and incremental damage over decades, and even going back to our childhood experiences, that eventually overwhelmed the brain’s ability to cope and lead to dementia.

So, when you think about poverty as a risk factor for dementia, there’s a couple of answers. The first thing we know is that dementia does follow a social gradient. And what we mean by that is that we’ve got New Zealand data that shows that people living in the most disadvantaged and the highest levels of poverty in New Zealand have a 50 percent higher risk of dementia compared to people living in the most affluent areas.

But what we’ve also been able to show is that risk factors follow the same social gradient. So, a lot of the risk factors that have been talked about by Alzheimers New Zealand, that have been in the media for the last few years, also follow that social gradient. So, people living in poorer areas are more exposed to many of these risk factors.

Q. Who is the most affected?

I think the way to answer that is to consider what it is about poverty and social disadvantage that increases people’s risks. The first comment I’d make is that since probably the 1960s, 1970s, we’ve kind of shifted in our way of thinking about health and health behaviours, and approaches to health and lifestyle. And we really move from a societal approach of saying that our health is determined by our environment, to health is an individual responsibility and that it’s a choice that people make. And when it comes to things like poverty, we know that the social and commercial determinants of health – where we live, work and play – really influences the choices we can make, and our ability to live a healthy lifestyle. If you’re living in a poorer area and you’re surrounded by things that make healthy living more difficult, then it’s perhaps unsurprising that risk factors for dementia are higher in those people.

A lot that we’ve done in New Zealand shows that we have a higher exposure to many of these risk factors for dementia. But that also means if we can prevent those risk factors, we can reduce the levels of dementia quite significantly in New Zealand. We’ve also shown that some population groups – particularly Māori and Pacific populations – have a higher burden of many of these risk factors and therefore have a higher risk of dementia. But there’s nothing innately risky about being Māori or Pacific – it’s the fact that they are disproportionately living in much poorer areas in New Zealand. It’s the fact they’re living in poverty and social disadvantage that’s driving their higher risk of dementia rather than anything to do with ethnicity or culture.

Q. What can be done to help combat social disadvantage?

A. A lot of the evidence and a lot of the research that’s been done to date overseas has really focused on what we could change in the individual – what a person can do to change their lifestyle to address some of these risk factors and reduce their risk of dementia down the line. How effective those individual approaches have been, is up for debate and there’s some evidence that they might make a bit of a difference. But there’s quite a bit of evidence out there that they’re not making much difference. And the question really is why?

I think it comes back to my earlier point that we are a product of our environment, where we live, where we work, where we play, where we exist, and kind of go about our day-to-day lives really influences our ability to live a healthy lifestyle. So, we need to move away from telling people at an individual level they need to change and start thinking about what we can change at a population level, at a societal level. What kind of policy changes we can make, what kind of legal reform we can put in place, so that it’s actually easier to make healthy choices. So we can shift the societal norms make it easier to live a healthy lifestyle and effect unconscious behaviour change.