Effects of ageing on the senses

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 grass underfoot? Or a burning smell in the kitchen? 

As we grow older, most of us notice that we need the volume turned up a little on the television, or 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 i.e.

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 certain amount of stimulation is required before the brain becomes aware of a sensation. The minimum level of stimulation is called the threshold. Ageing increases the thresholds so that a higher level of stimulation is needed in order to be aware of the sensation.

We might need more seasoning on our food for example or 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 wear and tear of the peripheral sensors – the eyes, the ears or the tongue say – our sensory perception may also be affected by 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 disease including dementia, or injury to the nervous system or 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 it can vary widely among individuals.

The good news is that accelerated decline in later years is not the norm of healthy brain ageing.

How many people are significantly affected?  

The charity Action on Hearing Loss estimates that around 11 million people in the UK suffer from hearing loss - of whom over half 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.

Research published in the UK in 2015 identifies that loss of smell affects up to 50% of people aged 65 -80 (and a majority of those aged over 80)

According to the charity Fifth Sense loss of taste is much less common than smell, but ageing is one of the most common causes

At the time of writing, no figures were available on the loss of touch. 

What we can do to protect our senses? 

To find out more read our article on this (Protecting our Senses). Key points are: 

  • Follow a healthy lifestyle – avoid smoking, eat a healthy diet and 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 

Conclusions 

  • 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 and 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 (effectively reducing the sensitivity of our senses). 
  • It is estimated that loss of hearing affects around 11 million people in the UK, that nearly 2 million people are living with sight loss and that loss of smell affects a majority of people aged over 65. 
  • Fortunately a healthy lifestyle, a healthy environment and seeking medical advice when needed can go some way towards helping protect our senses.

To return to Ageing and senses click here.

Rachel Laughton-Scott September 2016, Reviewed and updated by Emma Juhasz January 2017, Next review date December 2019.

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