Dementia is about to become an increasingly urgent problem for many Kiwis. While scientists grapple with its complex causes, prevention remains a useful tool. By Sarah Catherall.

Fred Browning doesn't know it's Monday – the 72-year-old just knows it's the day he goes to a cognitive therapy group in Wellington City.

On Thursdays, he spends the morning at a neurological choir session, and in the evening, his son and grandchildren come for dinner. Recently, the former BNZ banker forgot what he'd had for dessert. "When are we going to have our ice cream?'' he asked, 15 minutes after he'd eaten it.

Nine years ago, his wife, Yvonne, began to suspect her husband was developing dementia. She happened to be working as an occupational therapist in a geriatric team, helping elderly people with the condition, so she knew the signs.

Fred was 63 at the time. He began forgetting things, had no desire to get a job, and slumped into a bout of depression. "The thing that made me think, 'Uh oh', was when we were doing the dishes and Fred couldn't remember where the pots went,'' she says.

Sitting in their sun-drenched kitchen in the Wellington suburb of Tawa, Fred chuckles that he's still expected to do the dishes: "It was a bit of a gradual thing for me.''

The couple took their time to share the news with friends and family, including their three sons, who are now in their forties. Says Yvonne: "We hoped it was a misdiagnosis. We waited to tell people until we got used to the idea. We felt that people would judge him.''

An estimated 70,000 Kiwis are currently affected by dementia. The most common type, which accounts for about 70 per cent of cases, is Alzheimer's – a cruel disease with no cure, and one that causes the brain to slowly shut down and die.

Our ageing population and increasingly sedentary lifestyles have prompted Alzheimers New Zealand to issue a stark warning that 3 per cent of Kiwis will have dementia by 2050, including 10 per cent of all superannuitants.

The organisation fears a looming crisis if we do not dramatically increase the number of facilities to care for dementia patients.

Backed by some of the country's leading dementia specialists and neuroscientists, it has written a national dementia action plan that it wants the Government to implement, or to use as the basis for its own. That was something the World Health Organisation called for back in 2012, when it warned that dementia was likely to treble in three decades.

Alzheimers NZ chief executive Catherine Hall says both Labour and National pledged in their last election manifestos to develop such a plan. In the one jointly written by Alzheimers NZ, the NZ Dementia Foundation and Dementia NZ, they call for urgency on reducing and preventing dementia, supporting people and their carers, tackling stigma and boosting the dementia workforce.

"The population is ageing at a rapid rate and nothing has been done to prepare for that and to support the services we will need," says Hall. "New Zealand services aren't coping now. People are already struggling to get a diagnosis and there aren't enough services to support them.''

She is particularly concerned about Māori and Pasifika communities, who experience higher rates of dementia at an earlier age. Families are already providing more than 50 million hours of unpaid care a year, she says. District health boards can't keep up with current demand, let alone the expected surge, and thousands of families have no care or support.

"We've been raising this as an issue since 2008 and, meanwhile, the problem is worsening by the year,'' she says.

The aged-care sector is also concerned. As of September, there were 4519 dementia residents in 226 dementia units, says Aged Care Association chief executive Simon Wallace. While the overall bed occupancy rate was 88.8 per cent, some units were completely full. There is already a shortage of nurses in aged care, and the situation will only get worse, he believes.

Retirement village operator Ryman Healthcare has almost 1000 beds in 29 specialist dementia units at villages on both sides of the Tasman. It plans to add just over half that number again in the medium term. "There are often waiting lists, and we give our residents already in our villages priority access," says corporate affairs manager David King. "Our care centres generally run at 97 per cent full. There is no shortage of demand. And that's before the baby boomers really start arriving.''

Yvonne Browning describes her husband's dementia as "slow burning''. "He's doing pretty well,'' she says. While he has stopped driving, he is building a fence for a neighbour, waters his garden daily and helps around the house. He also enjoys Sudoku.

Routines are important, says Yvonne, and she is doing everything she can to ensure Fred has an active life full of fun, stimulating and happy times.

"Fred and I don't focus on the 'can't do', we focus on the 'can do'. I modify things so that Fred can do them. I think the big thing for people living with people with dementia is to be accepting of change. Lower your standards a bit."

About 10-15 per cent of people with Alzheimer's are thought to have inherited it. Two of Fred's six siblings, including a younger sister who was in her early sixties when diagnosed, also have Alzheimer's, so Yvonne believes there is a genetic link.

She is also the chair of the Younger Onset Dementia Aotearoa Trust (Yodat), set up by Dr Sally Rimkeit, a Wellington-based psychogeriatrician. Rimkeit says the current Government focus to keep a person with dementia out of residential care only works if there are quality day services available, but these are lacking.

Research is increasingly showing that social connection slows down dementia, and cognitive stimulation is vital. If a person hibernates at home with a stressed carer, that accelerates the disease, she says. "About 25 per cent of people with dementia have depression, and carers get depressed, too.''

Yvonne runs Yodat day services twice a week, and Fred is the consumer member on the board. On Monday mornings, he sits around a long table in a rambling Thorndon villa with about a dozen other people with early-onset dementia. They talk about current events, do some activities and provide companionship for each other.

At times, they're slow to answer questions, but they're engaged. However, there can be a wide variability in how the disease affects people, notes New Zealand's leading neuroscientist, Sir Richard Faull.

Faull is founder and director of the Neurological Foundation Human Brain Bank and the Centre for Brain Research, overseeing teams of neuroscientists who are trying to determine the causes of dementia and other neurodegenerative diseases, and how to potentially delay or avoid them.

He says there's a "general consensus" that dementia can be prevented through lifestyle choices. "But when you talk about dementia prevention, you're not necessarily talking about prevention forever. There are aspects of the scientific survival of brain cells in which we don't understand how to reverse that ageing process.''

There is still no cure for Alzheimer's, but teams here and around the globe are increasingly working on ways to detect it early before tau and amyloid proteins begin killing off brain cells. Faull reels off the risk factors: "Smoking is terrible, a killer for the heart and the brain. If you've got diabetes, get it treated. High blood pressure, especially in midlife, is a risk, along with obesity. They're prime factors for heart disease, and also brain disease.''

The heart and brain are perfect partners, says Faull. "Every time your heart pumps blood around the body, 20-25 per cent of that goes to the brain. Keep your heart healthy and you'll keep your brain healthy.''

One of the latest findings is that 80 per cent of people with dementia have hearing problems. This follows on from research published in the Lancet last July, which found that hearing loss and obesity are the biggest preventable dementia risks for New Zealanders.

Faull says it's not clear whether hearing loss is a cause or effect of dementia. However, getting your hearing treated so you're having better sensory input into your brain is important, he believes.

He also stresses that dementia progresses more rapidly when someone shrinks from society. "Dementia is like a new state of mind and people need to be given hope. Point out all the things they still have. If a person with dementia says it's Thursday, well, it's Thursday. It doesn't matter. Don't try and correct their brain because you can't do that, and you'll antagonise them. Help them do the things they can, and do more of them.''

Angela Caughey is a fine example of that can-do attitude.

Speaking by Zoom from her apartment in a retirement village in Auckland, the 92-year-old is determined to challenge herself in new ways every week. She has taught herself to juggle, learnt the national anthem in Māori, bowls every week and is the oldest person in the village's exercise class. She eats dark chocolate every night after dinner and has discovered chia seeds.

Caughey nursed her husband, Brian, for 12 years while he had Lewy body dementia. He died in 2006, aged 84, and Caughey made it her mission to spread the word about how to communicate and care for someone with dementia. She has just published her third book on the subject, A Better Brain for Life.

In the book, she notes that neuroscientists around the globe are increasingly focused on detection and early intervention. They are starting to make the connection with other chronic illnesses such as heart disease, diabetes, high cholesterol and renal disease. She believes that diet, exercise, mental stimulation, stress, sleep and socialising are key to avoiding or delaying dementia.

Although ageing and genes clearly play a part in causing dementia, she believes at least a third of the risk is down to lifestyle. She also notes that the brain shrinks by 0.5 per cent a year from the age of 60.

She refers to one study of 2500 Welsh men in 1974 who participated in a 30-year survey where their healthy lifestyle was measured and compared with 15,000 other men who were largely unhealthy. In 2004, the two groups were compared: the survivors were aged 75 to 80, and the healthier group had about 60% less cognitive impairment and dementia than the less healthy group.

Along with avoiding the obvious dementia risk factors, Angela stresses the importance of getting the right vitamins and blood tests throughout life: high levels of homocysteine (an amino acid) and high cholesterol have been linked to dementia. "If you are lucky with your genes, your brain … will continue to be your valued friend and tool for everyday use – but keep it busy,'' she writes.

A Better Brain for Life came about because Angela wanted to back up what she had learnt with the latest global research. She says that a healthy brain that will age well can be grown in the womb. And all through life – childhood, adolescence and adulthood – mistakes are made that can put someone at risk of dementia.

In the foreword to her book, David Smith, an emeritus professor of pharmacology at the University of Oxford, endorses her views. "The next step in science will be to develop what is called 'precision medicine', in which the risk factors we are exposed to are identified and then are modified according to our genetic make-up," he writes. "In the meantime, governments should adopt policies that will reduce our exposure to known risk factors, such as controlling air pollution, reducing inequalities leading to socio-economic deprivation and regulation of food to ensure adequate nutrition at all stages of life.''

Angela suspects her husband's lifestyle helped lead to his dementia. He was often concussed when he played rugby, and regularly weed-sprayed their lawn tennis court in bare feet. "Sometimes you don't know that the choices you make throughout your life are dementia risks,'' she says.

Meanwhile, Kiwi neuroscientists are working on some potentially groundbreaking research, which, if it works, could help identify dementia risk before brain cells begin dying.

Faull says there's not yet a lot that can be done to help the genes overcome a genetic defect that could give you a tendency to dementia – but one day there might be. "Identifying genetic factors is really important. And also, we are identifying genes that suppress or mutate bad genes. We're looking at all that. That's the most exciting research being done at the moment.''

He says the search for a cure is still very much like looking for needles in a haystack. "We still don't understand what causes this disease. But we do know that every single person with dementia is different. Genes play a role in some, and it's not all due to one factor. But we'd love to know: what makes that first [brain] cell die? Since we're not there yet, slowing the death of the cells and decreasing it is so vitally important.''

In June last year, a new drug called aducanumab, sold under the brand name Aduhelm, received enormous global attention, becoming the first new Alzheimer's drug to be approved by the US Food and Drug Administration (FDA) since 2003. It has been suggested the drug works like an Alzheimer's vaccine, as it removes amyloids.

But it remains controversial, as the approval was fast-tracked despite a lack of sound evidence that it is effective. Many experts, including some FDA advisers who resigned in protest over the decision, believe the approval was driven by desperation to offer people hope, rather than by the science. The drug has not yet been approved in Europe, Australia, the UK or New Zealand.

According to University of Auckland neuroscientist Professor Maurice Curtis, the latest thinking is that tau may be more important in treating Alzheimer's. While he expects more therapies around that, "we're still in the waiting phase".

In the meantime, with life expectancy continuing to increase, prevention seems to be the best tool we have, says Curtis. “We are treating heart disease [with medication] so people are living longer now. The brain is the logical one to treat next.”