There is no cure for this disease that affects millions - but lifestyle modifications can reduce the risk. Sophie Morris takes a test to find out what her future may hold
Afew weeks ago, I had a blood test that might revolutionise diagnosis and treatment for Alzheimer’s disease, a terrible condition affecting millions worldwide for which there is currently no cure. The test, known as p-tau 217, detects whether traces of Alzheimer’s disease are already taking root in my brain.
As soon as I’ve taken the test, with a two to three week wait for the results, I shove the possibility of bad news to the back of my mind and leave it there.
I’m only 45, after all, I tell myself. There is no history of early onset Alzheimer’s in my family. Yet I do experience memory loss, or what’s popularly known as brain fog.
In fact, I struggle to recall words and names most days and have done for years. The day after having the test, I asked my daughter to remind me of the name of “that frozen sisters Disney movie” (Frozen).
My phone is registering over 50 pickups a day because half the time I unlock the screen then forget what I’m there for. But I put this down to age and exhaustion.
So far, very few people have had the test. Professor Tim Spector (inset, right), founder of the Zoe diet app, is one. At 66 and with dementia in the family, he wanted to know his prospects and he wrote about the experience recently.
I went to the same clinic in London’s Marylebone, a world-leading hub for longevity and lip fillers.
My test was administered by Dr Sabine Donnai, the founder and CEO of VIAVI, which specialises in preventative health and in particular brain health.
Dr Donnai has formerly held senior clinical positions at Bupa and Nuffield Health, but is more used to treating burnt-out international business leaders than jaded freelance writers.
I can tell that she is older than me but I know she looks much better, with sparkling eyes, clear skin, beautiful tailoring and a friendly but professional manner.
I decide I want to know my outlook, even if it’s earthshatteringly bad The process is a straightforward, pain-free (assuming you don’t have a problem with needles) blood test. I sat on the clinic bed, held my arm out and it was all over within minutes.
Decades of research has shown that proteins called amyloid and tau build up in the brains of those with Alzheimer’s.
The p-tau test detects these proteins 10 to 15 years before symptoms appear. Dr Donnai compares it to evidence that might be seen on a scan before someone has a heart attack.
“You would have plaque formation in your arteries if you’re diabetic, or your blood pressure is high or you’ve got high cholesterol,” she explains.
“The artery wall is trying to protect itself with the calcium, which puts you at risk of heart attack and stroke. A similar process happens in the brain with Alzheimer’s.”
She says when the brain detects an irritant, it protects itself with these tau protein entanglements. Before, they could only be detected by an invasive lumbar puncture, a procedure that definitely wouldn’t be used on anyone without symptoms.
“Now, we can do it in the blood, which is amazing because if you see p-tau protein in the blood, you know that there is p-tau protein in the brain. Does that mean that you will get Alzheimer’s? No.
“What it does mean is that the brain is reacting to an irritant. And you can start investigating and do something about it.”
I’m also offered testing for GFAP (glial fibrillary acidic protein), which might show signs of Parkinson’s or general cognitive decline, and NFL (neurofilament light), a protein that is elevated in a number of brain conditions that aren’t Alzheimer’s as well as head trauma.
The three tests, which VIAVI calls the Cortex Tri, cost £1,800.
Dr Donnai tells me that the risk of getting Alzheimer’s is only 10 per cent related to genetics. Early detection gives people the chance to look at other factors including environment, eating habits and lifestyle.
Even those with a genetic risk for Alzheimer’s can reduce their chances of getting it dramatically through consistently changing their daily habits.
I do worry a little before getting my results, but decide I would rather know, whether good or earth-shatteringly bad, and then make my own choices about how to live.
That said, another worry is that I might discover a problem but find it is too expensive to treat.
Dr Donnai’s usual clients, the ultra rich, come armed with the expectation they can pay for any future treatment, whereas I’ll be left with whatever the NHS offers.
Tim Spector did not find evidence of Alzheimer’s, but on taking further tests with VIAVI - its 360 brain health screening, which costs £12,000 - he discovered some early warning signs of vascular dementia, as well as very high levels of environmental plastics in his blood.
He wrote that these may have been elevated by his 30 years of cycling around London. He can’t do anything to rewind that, but resolved to buy more eco-friendly shower products to reduce his exposure to toxins and microplastics.
When the moment arrives for my feedback session, I am put out of my misery immediately. The news is good. As I expected, age appears to have played in my favour.
“It’s a super sensitive test,” Dr Donnai says. “You are clearly very negative. That means that your brain is kind of safe for the next 15 years, which is good news.”
I am delighted, especially since all of the tests come back negative. This doesn’t explain my forgetfulness, but maybe a decade of poor sleep is the more likely culprit.
‘We can all lower our risk of dementia with lifestyle ’ So if this test is now available, should it be offered more widely?
When I speak to Jonathan Schott, professor of neurology at UCL and Alzheimer’s Research UK’s chief medical officer, he expresses misgivings. “I don’t think you should have had those tests done,” he says. “That’s the advice I would give to anybody, including my own family.”
This surprises me, not least because Professor Schott is running his own trial of the same test.
He hopes that this research will lead to diagnosing Alzheimer’s and other forms of dementia on the NHS, via blood tests, within five years.
He aims to see whether measuring p-tau 217 improves the rate of diagnosis for those with early dementia or progressive memory problems.
“An early, accurate diagnosis of Alzheimer’s disease is already important, allowing people to access appropriate medications,” says Schott. “If, as we hope, new treatments that can slow down Alzheimer’s disease become available soon, then this will be vital.”
But he says a positive test doesn’t mean that someone will develop dementia. “If you get a positive test, it’s potentially concerning but we don’t know quite what that means.”
He has been following a healthy cohort born in 1946 for a decade. Of the 20 per cent who tested positive for Alzheimer-related proteins at 70, 10 years later, very few are showing signs of dementia.
What’s more, doctors don’t know how to counsel someone who does receive a positive result, apart from offering them entry into a clinical trial and helping them to work on those lifestyle factors that can affect the onset of dementia.
“There is almost universal consensus among experts that these blood tests should not be routinely used in people who do not have symptoms, outside of research,” he says.
Just last week, Alzforum, a news and research site dedicated to the disease, reported that while 80 per cent of healthy people said they would want to know if they had related proteins on their brains, when it came to it, only 60 per cent chose to find out.
Professor Schott clarifies that he is extremely excited about the test’s potential. “It’s a very optimistic time, but we need a bridge between what’s possible in research and what’s practical for the NHS,” he says.
“We need better diagnostic tests and treatments for people who are getting mild symptoms, and in due course we need to think about identifying people before they have symptoms - perhaps via blood tests - but at the moment we don’t have the evidence.”
He points out that 30 to 40 per cent of cases of dementia in the UK are preventable - meaning they could be avoided if we tackle a group of 14 risk factors including smoking, alcohol consumption, high blood pressure, hearing loss, obesity, diabetes, depression and air pollution.
Everybody should be looking to optimise these, he says, and can do so without the insights of an expensive test. I see his point, but also think that seeing medical evidence can push people towards changing their behaviour.
Why my result made me look at my diet Dr Donnai’s approach is to try and prevent people from getting ill before they show any symptoms. I put Professor Schott’s concerns to her and she is visibly frustrated.
“My perspective is exactly the opposite,” she replies. “We now have a very good understanding of the lifestyle drivers that increase your risk of Alzheimer’s. You wouldn’t wait until you have a heart attack to do something about your cholesterol or your weight or your blood pressure.
“I cannot get my head around how there are still people, very intelligent people, stuck in the mentality that we should not highlight and try and influence the outcome, because it’s a horrible disease.”
She argues there is great benefit in finding out which of the modifiable risk factors are the troublemakers for individuals, so they can focus on these rather than trying to live a squeaky-clean existence, which we all know is hard to stick to.
Dr Donnai also gave me a fourth test, guessing from other recent blood results that I may have abnormally high levels of homocysteine. This is an amino acid that we all have, which can increase the risk of cardiovascular disease as well as dementia if too high.
Dr Donnai says we should have a result of around seven. The NHS puts that range at five to 15. My number is 59, the highest she has seen.
High homocysteine levels are associated with low levels of serum folate, which we get from leafy greens. It seems strange as I eat them several times a day. I’m advised to take an additional supplement.
I feel fortunate to have taken the test and ended up with a negative result, though given my age it’s possible £1,800 could be better spent on improving the other modifiable lifestyle factors that play a part in developing dementia.
I look forward to Professor Schott’s research identifying how useful the p-tau and other tests might be in diagnosing Alzheimer’s and other forms of dementia before symptoms advance.
Let’s hope that in less than 15 years - when Dr Donnai says it could be time for me to test again - everyone has access to the tests.
FAST FACTS DEMENTIA
Dementia mainly affects older people and, after the age of 65, the likelihood of developing dementia roughly doubles every five years Dementia is currently the leading cause of death in the UK. Dementia and Alzheimer’s disease accounted for 11.5 per cent of all deaths registered in England and Wales in 2022.
In the UK, the estimated economic impact of dementia in 2024 was £42.5bn, a figure that is expected to more than double by 2040.
The number of people living with dementia in the UK was estimated to be close to one million in 2024 (982,000). By 2040 this figure is expected to rise to 1.4 million.
Approximately 57 per cent of the 982,000 people living with dementia in the UK are women.