This blog post is in the form of a dialogue (email exchange) between Aldo Mussi, one of our Public Health @BCU team, and Catharine Jenkins, a colleague who is a Senior Lecturer in Mental Health Nursing, with a special interest in dementia.
Aldo: Dear Catharine. Media discussion of dementia often revolves around hopes for a cure, but a Public Health perspective on an illness would look more at how to prevent it occurring – and for this, we first need to identify the causes. What is known about the biological, psychological, social and environmental causes of dementia (or ‘dementias’, if they differ)?
Catharine: Good to hear from you. I agree, thinking about the broader factors that may be contributing to risk of dementia is very important. I think we get very mixed messages from the media, it’s as if a magic wand is just around the corner, about to bring us the ‘cure’ so we can bury our heads in the sand about anything we can do ourselves as individuals or as a society, that could reduce risk. But at the same time we are often told ‘use it or lose it’!
I suppose part of the problem is as you suggest, that understanding the cause is key. There are many different types of dementia and some different theories about causation. For example Lewy Body disease is very like Parkinson’s disease. As Alzheimer’s type is the most common I’ll stick to discussing that, although it seems increasingly likely that many people with Alzheimer’s have a mixed type of dementia where vascular factors are also involved. Generally for health promotion advice the clearest message seems to be ‘what’s good for your heart is good for your head’.
What’s good for your heart is good for your head
But anyway, getting back to your question about causes, the most likely scenario is that there is an element of genetic risk the impact of which is then built upon or lessened over the years by other factors. Some peoples’ brains may be less well able to manage the amyloid protein which can build up in brain cells (and eventually kills them – the cells!) over time. We all have these proteins, but too much is not good. So given that amyloid is there, it’s a question of how can we reduce the amount, help our brains to deal with it, and help our brains to keep going when the number of neurones is reducing. Researching how to do this is quite difficult when brains are difficult to look at when people are alive and the brains of mice are only like ours to some extent. There have been a lot of drug trials that had great results on mice with dementia but then had harmful effects on humans.
Some of the research on causes has looked at the ‘amyloid cascade’ theory, which suggests that genetic and environmental factors tip the brain into a process where the amyloid and another protein ‘Tau’ trigger one response after another until the number of neurones is diminished to the extent that it is clear that the person is struggling with various abilities that we associate with dementia (memory, organising themselves, communicating and orientating themselves are some examples). But by the time the problem is obvious on the outside , it is late on in the process happening inside and too late really to do much about it. So we need to look at potential contributing factors way before – maybe 20-30 years before – anyone suspects there might be a problem.
One way of looking at factors is considering characteristics and history of people who go on to develop dementia and those that do not. Protective factors include having a healthy diet with lots of vegetables and fish, exercising regularly, minimising alcohol consumption, not smoking, having a good education and a challenging job (good news?) and being sociable. Being bi-lingual gives five years protection too apparently! Risk factors include not doing or having those things, but to add to that a history of depression in middle age is a risk factor. As is of course just getting older! Women are at more risk than men. So there are some things we can’t do much about, but the main things seem to be protecting the brain’s circulation and resilience with health promoting behaviour, then working it so that there are neuronal connections that will step up (this is called ‘brain reserve’) if some are damaged.
These factors seem quite individual in orientation, but perhaps I’ve overlooked the context of individuals in society. Perhaps I should have thought about the role of stress in heart disease and circulatory disorders, or the expense of eating well, having a safe place to exercise? How would you see things more broadly? And what would you recommend from your professional perspective?
Aldo: Dear Catharine, your comparison with heart health is useful, particularly in reminding us that dementias are complex and have multiple causes (many of them outside of the control of individuals) – but where individuals feel they can do something themselves, you may have a great campaign slogan there : “What’s good for your heart is good for your brain”!
As you also say, it’s important to recognise the limitations of a ‘lifestyle’ approach (especially if it over-emphasises dieting & sport, as heart health initiatives tend to).
Public Health England’s Annual Plan 2015/16 mentions ‘reducing dementia risk’ as a desired outcome, but it’s very disappointing that the only action cited is to ‘successfully transition the ‘Dementia Friends’ programme to the Alzheimer’s Society’.
Perhaps a more comprehensive and effective dementia prevention strategy would be one that stops creating a society/environment which encourages dementia, but adapts it so that it takes into account the identified causes you mention, and so promotes :
- A food culture based on mainly plants with some fish.
- A drink culture based on far less alcohol and sweet drinks.
- Greater restriction of the tobacco industry.
- Daily routines where people are physically active (in work, travel & play).
- Work which is stimulating and satisfying for all.
- A culture where education for life, for all, is valued – & that it emphasises personal and social development.
- Encouragement of ‘The 5 Ways To Wellbeing’ (which includes having more social connection, and fosters good mental health generally)
- Much greater social & financial equality (so that, eg ‘a good education’ is for all, not just for an elite, and so that women are less disadvantaged)
- Multi-lingualism ! (Perhaps if England stops isolating itself linguistically, there will be a number of other benefits too).
Looking at this list, it has echoes of broad health strategies such as ‘Health For All’, and even the UN Declaration of Human Rights! Once again, it’s likely that if we get the basics right, then apart from being healthy & desirable in its own right, this will be beneficial for brain health, heart health and the prevention of many illnesses.