Seven signs you are at risk of dementia (Image: Getty)
A reduced sense of smell or regularly taking short naps at work, even when you are not feeling tired, may seem harmless or unrelated, but according to scientists, these behaviours could be a sign of something more significant. According to a latest study published in the Journals of Gerontology, unplanned daytime napping is linked to a higher risk of developing dementia.
Dementia is a collective term used to describe a range of conditions that affect memory, thinking, reasoning and the ability to manage everyday activities.
While Alzheimer’s disease is the most common form, there are several other types that can cause similar cognitive decline.
Symptoms often include memory problems, confusion, difficulty concentrating or making decisions, communication and language challenges, and changes in mood or behaviour.
Although the likelihood of developing dementia increases with age, it is not considered a normal part of growing older. Identifying the condition early can help people access appropriate treatments, support services and care more quickly.
A decade-long study by researchers at the Johns Hopkins Bloomberg School of Public Health in the US tracked 995 adults aged 65 and above who had no dementia at the beginning of the research.
The findings revealed that people who napped daily or on most days were 48 per cent more likely to develop dementia than those who seldom or never took daytime naps.
The increased risk remained even after factors such as existing health conditions and the length of night-time sleep were taken into consideration.
Below are the seven crucial warning signs:
1. Taking naps without meaning to:
Previous research has also suggested a connection between daytime napping and a higher likelihood of dementia. However, experts have yet to establish whether dementia-related changes in the brain disrupt normal sleep patterns, leaving people feeling more exhausted during the day, explained Catherine Loveday, a professor of neuropsychology at the University of Westminster and host of Mempathy, a podcast about making the most of life with dementia. She added that even minor declines in cognitive ability can make everyday activities require considerably more effort, resulting in increased tiredness.
Although a gradual reduction in walking speed is often considered a normal part of ageing, Ms Loveday points to substantial research linking slower walking pace with an increased risk of dementia. A nine-year study published in the Journal of Gerontology found that walking 0.204 metres per second slower than the average pace was associated with a 59 per cent greater likelihood of developing dementia. This association was evident even when walking speed was assessed up to seven years before a diagnosis.
Although reduced appetite is a recognised feature of dementia, research suggests that changes in eating habits may emerge long before a diagnosis. A 16-year longitudinal study published in the Journal of Aging and Health, which explored the relationship between body mass index and dementia using data from the American Health and Retirement Study, found that weight loss could start more than 10 years before the condition was diagnosed. A possible explanation was a loss of appetite.
However, eating less is also a natural part of ageing, so weight changes alone should not be treated as a warning sign. Dr Simon Wheeler, senior knowledge officer at the Alzheimer’s Society emphasised that alterations in appetite could nevertheless indicate that something is not quite right.
4. Hearing loss and ringing in your ears:
Research has consistently identified hearing impairment as a potential risk factor for dementia. A 2024 report led by Gill Livingston, Professor of Psychiatry of Older People at University College London, linked hearing loss to a 37 per cent higher risk of developing the condition. It also found that every 10-decibel decline in hearing ability was associated with a further 16 per cent rise in dementia risk.
5. Reduced sense of smell:
Ms Loveday highlighted a strong association between declining smell and memory problems, explaining that the olfactory bulbs, which process smell-related information and sit towards the front of the brain, are located close to the hippocampus, the region responsible for memory.
She suggested that both areas may be impacted by the same underlying disease process. Supporting this connection, a systematic review published last year in the International Forum of Allergy & Rhinology, which analysed 48 studies involving 37,783 participants, found that people with a reduced sense of smell were 2.14 times more likely to develop dementia than those with a normal sense of smell.
6. Poor spatial awareness:
Posterior cortical atrophy (PCA), an uncommon form of Alzheimer’s disease, affects the visual processing region of the brain. The condition, which led to the death of author Terry Pratchett in 2015, can cause visual disturbances that originate in the brain rather than the eyes themselves, Dr Simon Wheeler said.
She said anyone experiencing sudden changes in their vision to contact their GP and request a referral to a neurologist. For those noticing more gradual alterations, keeping a written record of symptoms can help track how they develop over time.
Persistent low mood may sometimes emerge in the early stages of Alzheimer’s disease. Ms Loveday explained that the hippocampus, the part of the brain where the condition commonly first develops, is also associated with depression.
This means changes in the brain caused by the disease could contribute to feelings of sadness, while growing awareness of difficulties with everyday functioning may also leave individuals feeling depressed.
