Dementia prevention: Alzheimer's expert Stephanie Rainey-Smith reveals change you can make to protect yourself

Dementia is now the biggest cause of death in Australia, with the latest data estimating the number of Australians suffering from it will increase 2.5 fold over the next 40 years.

More than 433,000 Australians are believed to be living with dementia and this has been predicted to grow to more than one million by 2065 according to new forecasts released this week by the Australian Institute of Health and Welfare.

It comes after the institute published data last year that WA was on track to see the highest growth in people with dementia in the country.

Nearly two-thirds of Australians with dementia are women.

And there is no cure for this devastating disease.

But this public health crisis is not hopeless or without remedy.

Associate Professor Stephanie Rainey-Smith, from the Perth-based Alzheimer’s Research Institute, believes eliminating risk factors for dementia, such as sleep, diet and physical activity, can prevent and treat cognitive decline.

“The message that I always give people is that it’s never too early to start, but it’s also never too late, and you should make any changes that you possibly can to help reduce your risk,” she said.

Professor Rainey-Smith said changes in the brain start to occur about 20 years before a diagnosis of Alzheimer’s disease, so it was important to take steps to prevent damage in mid-life.

Dementia is a brain condition that is not a normal part of ageing and affects mood, memory, thinking and behaviour.

Alzheimer’s disease is the most common form of dementia, where abnormal protein accumulations, such as beta-amyloid “plaques”, disrupt brain function and eventually cause death.

New therapies to treat Alzheimer’s disease involve drugs that target and clear the built-up plaque, but improvements in cognitive function have been limited and side effects a concern.

Last month, the Federal Government decided not to subsidise the newly-approved Kisunla (donanemab) on the Pharmaceutical Benefits Scheme, leaving patients to pay up to $80,000 a year.

Professor Rainey-Smith said because these drugs were not suitable for or accessible to everyone, “we must not stop thinking about modifiable risk strategies that we can all implement that can help reduce our risk of developing dementia”.

Last year, British medical journal the Lancet published a report listing 14 modifiable risk factors for dementia which, if eliminated, could prevent almost half of dementia cases.

Five of the risk factors are diet related: high blood pressure, obesity, diabetes, excessive alcohol consumption and high levels of low-density cholesterol.

Professor Rainey-Smith, who also leads the Lifestyle Approaches Towards Cognitive Health (LATCH) Research Group at Murdoch University, said a healthy diet was very important for memory and thinking and was linked to slower rates of amyloid accumulation in the brain.

The Mediterranean diet and the MIND (Mediterranean-DASH Intervention for Neurodegenerative Delay) diet have been linked with fewer signs of Alzheimer’s disease. Both are rich in vegetables, fruits, whole grains, olive oil, beans and fish, with the MIND diet also including berries and nuts.

Less education in early life is a risk factor that could explain why women are currently suffering dementia more than men.

Professor Rainey-Smith said education has a protective effect in preventing dementia because it increases the brain’s cognitive reserves, which help it to tolerate the damaging plaque build-up of Alzheimer’s disease.

“If we look at our older adults now, there probably would have been a disparity between access to higher levels of education for women versus men,” Professor Rainey-Smith said.

“It’s quite possible that women would have not gone onto tertiary education. They might have left school earlier, and they might have stayed at home to look after the children and whilst that’s all extremely important and valuable work, it’s possible that that may have contributed to have less cognitive reserve.”

Menopause is thought to be another reason why more women suffer dementia more than men.

Professor Rainey-Smith said sex hormones have a protective role with memory and thinking and the sudden drop that happens at menopause was likely to increase the risk of dementia in the future.

Hearing loss and untreated visual loss are also risk factors because the parts of the brain that processes those senses are no longer being used properly.

“In your brain, you’ve got to keep using it. You’ve got to keep stimulating it, to keep those connections there and to stop them from disappearing and diminishing,” Professor Rainey-Smith said.

The Lancet report said exercise at any age was helpful for cognition, possibly through changes in blood flow from lower blood pressure and increased nitric oxide, which improves brain plasticity and reduces inflammation.

Social isolation and loneliness are associated with an increased risk of dementia.

The Lancet report said any form of social contact potentially reduced the risk of dementia by building cognitive reserve, promoting healthy behaviours and reducing stress and inflammation.

Professor Rainey-Smith said social isolation could be one factor in why WA was estimated to see the highest growth in dementia cases in Australia by 2054.

The Australian Institute of Health and Welfare and Dementia Australia data, released last year, showed WA was expected to see a 109 per cent growth in dementia cases, compared to 93 per cent overall nationally.

“It can be related to the fact that WA will have a lot of older adults by that year,” she said. “It can also be related to having regional populations because we know that modifiable risk factors can differ between regional areas and metro areas, and some of that relates to access to support services and so forth.”

A new study of Australian adults aged 70 and older found that people living in more densely populated, greener areas with better access to services were less likely to develop dementia.

The University of NSW and Australian Catholic University research, which was published last month, also found that those exposed to higher levels of air pollution — another modifiable risk factor identified in The Lancet report — were more likely to develop dementia.

Access to public transport, parkland and coastal or blue spaces were linked to a better chance of recovering from mild cognitive impairment, which is a precursor to dementia.

Professor Rainey-Smith said sleep was very important for brain health, particularly mood, memory and thinking.

“We also know that when we’re sleeping, the brain’s housekeeping system kicks in, and it cleans out a lot of the toxic waste that accumulates during the day whilst we’re awake, and one of those factors is the amyloid that can accumulate in the brain,” she said.

Professor Rainey-Smith said reducing stress levels and improving gut health with probiotic and prebiotic foods or supplements could also help to reduce dementia risk.

“If someone tells me that they’re concerned about their memory and thinking, I always recommend first of all they go and get their thyroid and their B vitamin levels checked, because those are reversible causes of issues with memory and thinking,” she added.

Cellina Prosser has been taking steps to reduce her risk of dementia after her 80-year-old mother was recently diagnosed with the disease.

The 50-year-old mother of two said she had already cut out sugar and alcohol and been eating a healthy diet for many years to reduce her cancer risk.

“It (dementia) is a concern because there is not a lot known about the causes and especially given now it’s a family issue,” she said.

Ms Prosser is now focussing on improving her sleep and reducing stress, as well as taking hormone replacement therapy, to maximise her brain health.

Ms Prosser, who is a teacher and runs her own arts workshops, said she believed being creative was important for brain health.

“The arts are really powerful and are really misunderstood and undervalued,” she said. “If we’re not using our creativity, which everybody has and needs to use, then your brain isn’t actually working.”