FOUR SUBTLE LANGUAGE SHIFTS THAT COULD BE EARLY SIGNS OF DEMENTIA
It strikes us all in midlife and beyond – you’re rhapsodising about a new book or programme, only to draw a blank when it comes to the name of its author or star. It’s equally common to worry that these memory slips could be a warning sign of dementia. But a growing body of research suggests we may be looking in the wrong place.
A major new review of studies shows the earliest red flags of dementia – which affects around one in 14 people over 65 in the UK – lie in the way we speak. From the speed and rhythm of our speech to the complexity of our vocabulary and sentences, these small changes are now being linked to the first stages of neurodegenerative diseases such as Alzheimer’s disease.
“Language is one of the most complex functions the brain performs,” says Dr Tim Beanland, head of knowledge and learning at the Alzheimer’s Society. “A conversation – holding the other person’s words in mind and converting them into meaning – relies on the coordination of a network of different areas of the brain,” he says.
When that system begins to falter, the effects can surface in our speech before other symptoms appear. One study published in The Lancet analysed speech patterns and successfully predicted who would develop Alzheimer’s dementia seven years later, more accurately than a battery of cognitive tests.
But what is simply part of normal ageing, and when might speech changes point to something more serious? Here’s our expert guide to the signs, and how to boost your language and brain abilities to help stave off dementia.
Slower speech
The speed of speech, rather than difficulty finding words, is a more accurate indicator of brain health in older people, according to a 2024 study by the University of Toronto.
A group of 125 healthy adults aged between 18 and 85 were given a series of cognitive and language tests. In one, they were shown pictures of everyday objects such as a dog or a car while hearing distracting words, and asked to respond as quickly as possible. This allowed researchers to measure how efficiently they could retrieve the correct word under pressure.
Researchers also analysed natural speech patterns, including how quickly participants spoke and how often they paused. These results were then compared with standard tests of memory, attention and planning.
As expected, word-finding speed slowed with age. But while picture-naming accuracy also declined, it was not linked to a broader drop in other mental skills. Instead, what stood out was speed. They also found that people who spoke more quickly in everyday conversation performed better across a range of cognitive tests, particularly those linked to executive function.
Dr Emer MacSweeney, a consultant neuroradiologist and chief executive of Re:Cognition Health, a leading clinic delivering trials of Alzheimer’s disease treatments, says: “If someone who has always spoken at a normal rate begins speaking more slowly, it’s a worrying sign.”
Saying ‘um’ and ‘ah’ more often
Most of us experience some degree of “lethologica”, or the so-called “tip-of-the-tongue” effect, where a word is just out of reach. As a result, we can find ourselves buying time with filler words such as “erm” and “ah” – and this is usually nothing to worry about.
“As we age, there are changes in the brain’s white matter, the wiring that allows signals to travel between different regions,” says Dr Beanland. “It’s like going from a three-lane to a two-lane motorway: information still gets through, but it’s slower.”
This slowing can make it more difficult to retrieve words quickly, leading us to rely more on verbal “placeholders” while we catch up. The frontal cortex, involved in attention, planning and decision-making, and the hippocampus, vital for forming new memories, are particularly affected by age-related change.
But the University of Toronto study, and others, suggest using these filler words can also signal problems with our executive function, which controls how quickly the brain takes in information, makes sense of it and responds.
So how can we tell if those “err…” moments are a sign of something more? “In people with early Alzheimer’s disease, it’s not just the occasional hesitation, but a pattern that becomes more obvious over time,” says Dr MacSweeney.
Longer pauses between words
Research increasingly shows that the length and frequency of pauses in speech are among the earliest detectable signs of cognitive decline. Even when someone is using the right words, they may leave noticeable gaps mid-sentence before producing them.
These pauses reflect a slowdown in the brain’s processing speed and the systems responsible for turning thoughts into language, rather than an inability to remember specific words.
In normal ageing, pauses tend to be brief. But in the early stages of Alzheimer’s disease, they often become longer and more frequent, disrupting the natural flow of conversation.
“Pausing more, and for longer mid-sentence, is strongly linked to the early stages of Alzheimer’s disease,” says Dr MacSweeney. “People will seem more hesitant overall, with their speech becoming less fluid.”
Saying ‘because’, ‘although’ and ‘when’ less often
In the early stages of Alzheimer’s disease, sentence structure can be affected, according to the latest research.
While people can still construct grammatically correct sentences, studies have found a shift away from multi-clause phrasing towards shorter, more linear sentences, as the brain tries to reduce the effort required to organise thoughts.
In practice, this can mean using fewer subordinate clauses, along with words such as ‘because’, ‘although’ and ‘when’, which link different strands of a sentence.
Instead of saying, ‘I didn’t go out because of the torrential rain,’ for example, someone might say, ‘I didn’t go out. It was raining.’
“The cadence and rhythm of what people are saying start to change,” says Dr MacSweeney. “Their sentences become less sophisticated and more fragmented.” Speech can also sound more formulaic, relying on familiar, repetitive phrasing.
As well as memory, this reflects a problem with executive function, which controls how quickly the brain takes in information, makes sense of it and responds. As with other language changes, some simplification is a normal part of ageing, but a noticeable shift towards shorter, less detailed sentences can be a red flag.
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What to do if you’re concerned
It is vital to keep finding ways to stimulate the brain as we age, says Dr Beanland. “There is evidence that this is protective and helps increase the proteins that support the growth of neurons, the brain’s fundamental units,” he says.
Learn a new language to stave off dementia
A 2026 study from the Rush University Medical Centre found that engaging in intellectually stimulating activities throughout life can lower the risk of dementia by 38 per cent.
Which is another reason to try learning a new language, alongside reading and writing – both consistently shown to act as a form of strength training for the brain, increasing grey and white matter.
Lifelong bilingualism has been found to delay the emergence of dementia symptoms by around four to five years. If that opportunity has passed, even a one-week intensive language course has been shown to produce a measurable improvement in focus – a benefit that continued for those who practised the language for an average of five hours per week afterwards.
Keep up with friends and try out harder puzzles
“Being socially active is great for exercising your language skills, as are word puzzles such as crosswords and Wordle – but it’s all about challenging your brain, so it’s important to keep stretching yourself by finding harder versions or trying to do them more quickly.”
Dr Beanland, author of the Brain Health Puzzle Book, says: “You also need to work on other areas of your brain, such as memory, numerical and visual skills – so look for puzzles that test those, too.”
Keep up the exercise and good diet
Other proven ways to minimise your risk of dementia include “exercise, eating a low-sugar Mediterranean diet, not smoking or drinking too much, and sleeping for no less than seven hours and no more than eight,” says Dr MacSweeney.
Exercise is particularly important: an Alzheimer’s Society review found that people who are physically active are up to 20 per cent less likely to develop dementia than those who are inactive.
“Even if you’ve started to experience symptoms, these are all helpful,” she says. “And the rest of us should be doing them throughout our lives – but it’s never too late to start.”
2026-05-06T07:20:47Z
