How does ageing affect our senses? Can we hear a smoke alarm? Is our vision up to motorway driving? Would we notice a wasp settling on the grass underfoot, or smell burning in the kitchen?
As we grow older, most of us notice that we need the volume turned up a little on the television, or we need a brighter light when reading or a little extra sugar in our tea. This is due to the well-documented fact that over the years our senses tend to become blunted.
This article provides a short overview of our senses:
- How our senses work
- Behind the scenes – our brain and central nervous system
- How many people are significantly affected?
- What we can do to protect our senses?
How our senses work
We experience the environment around us through sound, light, smell, taste and touch. This information is converted to nerve signals and carried via the central nervous system to the brain.
A minimum level of stimulation is required before the brain becomes aware of a sensation. This minimum level is called the ‘sensory threshold’. Ageing increases these sensory thresholds so that a higher level of stimulation is needed before we become aware of a sensation.
We might need more seasoning on our food for example, or we might need to turn the music a little louder. These adaptations to our lifestyle are easy to make.
Behind the scenes – our brain and central nervous system
However, in addition to the wear and tear of the peripheral sensors – the eyes, the ears or the tongue say – our sensory perception may also be affected by a gradual deterioration of the central nervous system and the brain itself. Messages are conveyed to the brain via routes that are susceptible to wear and tear and to disease, including dementia, or injury to the nervous system or to the spinal cord.
The process of ageing varies among individuals according to genetics, environment and lifestyle. It seems likely that this process begins in our 20s and 30s, but this can vary widely among individuals.
The good news is that problems such as memory loss associated with age-related changes in the prefrontal cortex of the brain, can be reversed by a healthy lifestyle.
How many people are significantly affected?
The charity the Royal National Institute for the Deaf (RNID) estimates that around 12 million people in the UK suffer from hearing loss, of whom more than 70% are aged 70+.
The Royal National Institute of Blind People (RNIB) reports that almost 2 million people in the UK are living with sight loss. This number is estimated to rise to 2.7 million by 2030, and over 4 million by 2050.
Loss of smell
Research published in the UK in 2015 identifies that loss of smell affects up to 50% of people aged between 65 and 80 increasing to 75% above 80 years old. There is a strong association between loss of smell and risk of death, but the mechanisms involved remain unknown.
Loss of taste
According to the charity Fifth Sense loss of taste, without loss of smell, is much less common than smell-specific disorders, but ageing is one of the most common causes.
Loss of touch
A 2016 study of older adults in the US found that 70% had a poor or only a fair sensitivity of touch.
To find out more, read our article on how to protect our senses.
The key points are:
- Follow a healthy lifestyle: avoid smoking and eat a healthy diet.
- Try to minimize disease and injury.
- Ensure a healthy environment – wear sunglasses when needed and limit exposure to very loud noise.
- Be alert to any marked or sudden change in your senses and seek medical advice promptly.
- We experience the environment around us through sound, light, smell, taste, and touch. Nerve signals carry this information via the central nervous system to the brain.
- If the central nervous system or the brain deteriorate – as a result of age or from an illness such as dementia – then this flow of sensory information can also deteriorate.
- As we age, the level of stimulation required to make the brain aware of a sensation also rises. This effectively reduces the sensitivity of our senses.
- It is estimated that in the UK:Fortunately, a healthy lifestyle, a healthy environment and seeking medical advice when it is needed can go some way towards helping is protect our senses.
- loss of hearing affects around 12 million people
- sight loss affects nearly 2 million people
- loss of smell affects 50% of people aged over 65.
Reviewed and updated by Barbara Baker, December 2021. Next review date November 2025.