Alzheimer's research shifts towards prevention and earlier treatment

By Ellen O’Dwyer of RNZ

Alzheimer’s disease is starting to be considered as a treatable and preventable condition, a major new report says.

The World Alzheimer Report 2026, released today by Alzheimer’s Disease International, says despite years of slow progress, clinical trials are now on the brink of diagnostic and medical breakthroughs.

The number of people living with dementia globally is projected to surpass 139 million by 2050, the report said, becoming one of the leading causes of death throughout the world.

But while a cure is still far away, medical research is radically shifting the understanding of the disease.

“I think for a long time there’s been a fairly nihilistic view in the dementia world, that it is something that can just happen as you age for example, and that we can’t do anything about,” neurologist, neuroscientist and Alzheimers New Zealand spokesman Dr Campbell Le Heron said.

“These trials are showing us that we can potentially do something about it – at least in certain situations – but I think our biological understanding of the condition is identifying ways we can actually prevent it,” he added.

In the past several years, drugs that slow the progression of the disease have entered the market internationally.

Le Heron said the drugs target and remove the amyloid plaque that’s been developing in the brains of sufferers years before they get symptoms.

Trials are underway – some involving New Zealand – which are treating people before they have symptoms to see if cognitive impairment can be prevented.

“We don’t know if that’s going to be the case yet or not, but I think we have to have a mind on the future because that’s what we’re hoping we will be able to show,” Le Heron explained.

“And if that’s the case, then we really need to ... be improving diagnostic pathways for people with cognitive impairment, but also thinking about how we can identify people at risk of developing cognitive impairment from Alzheimer’s disease.”

The emergence of blood tests to diagnose the disease is also a major development in detecting Alzheimer’s earlier, the report said.

Trials are underway developing the tests in the UK and Australia.

Le Heron said the disease was currently diagnosed through specialist brain imaging and lumbar punctures in the lower back – but these were hard for people to access.

The tests were still not perfect, he added, and would need to be one part of a full, clinical assessment.

“In my mind, one of the really important things in these tests is hopefully they’re going to be a whole lot cheaper than the current tests that we have and because it is a blood test, it will be much more accessible for everybody in the country, compared to just being seen at a specialist centre.”

Given these rapid developments, Le Heron said the Government needed to improve access to diagnostic tools, boost its specialist workforce, train up primary care clinicians and put funding into community-based dementia services.

“We cannot allow these advances to become available only to people who live near specialist services or have the knowledge, money and connections needed to access them.”

Māori, Pacific peoples and rural communities shouldn’t be left behind, he said.

Associate Minister for Health and Minister for Seniors Casey Costello was approached for comment.

Can you prevent Alzheimer’s disease through lifestyle choices?
The report referenced clinical trials which look at how lifestyle choices can alter the trajectory of cognitive decline – not in laboratories, but in kitchens, gyms and community centres.

One study, originating in Finland in 2009, set out to test whether lifestyle could protect the ageing brain. Participants aged between 60 and 77 enrolled in a two-year lifestyle programme including a focus on healthy diet, physical activity, brain exercises and social activity.

Those who implemented the lifestyle benefits gained about 25% more cognitive improvements compared to the group which didn’t, the report said.

Le Heron recommended exercising five days a week to the point you “get puffed”, eating a Mediterranean-style diet with lots of fruit and vegetables, and prioritising socialising.

So what about crosswords, or brain puzzles?

“The evidence for actually doing crosswords probably isn’t hugely strong. That’s not to say don’t do it, but I certainly wouldn’t neglect just being out amongst people and participating in the community, which we know is really important as well.”

This story was first published on rnz.co.nz