Come to your senses for the sake of your brain

A tragic example of the importance of early stimulation comes from a study of Romanian orphans in the 1990s. These unfortunate kids were institutionalised for long periods and suffered profound neglect.

When examiners assessed them, their cognitive development lagged way behind their peers who had not experienced the same disregard. Although those who were nurtured in loving foster families thereafter did partly close the cognitive gap, the difference remained over the longer term.

This, of course, is an extreme example, but even lesser insults can have a detrimental effect on your brain health.

As an expert in brain health, I am like a broken record when it comes to encouraging people to figuratively stretch their grey matter.

Through the wonders of neuroplasticity – the ability of our brain circuitry to change in response to our environment – novel and progressive cognitive tasks help us optimise our brain function and may help stave off the clinical symptoms of dementia.

At the most fundamental level, the brain takes in information through our senses – whether it be what we see, hear, feel, or smell. I have talked before about the connection between poor hearing and dementia risk: at a population level, more cases of dementia could be reversed or delayed by correcting hearing than anything else.

For something that is (usually) so easily addressed, this is critical to remember.

But what about our other senses? Well, poor vision also has direct implications for cognitive health.

The “Blue Mountains Eye Study” found that older adults with vision impairment had a 60 per cent higher risk of developing dementia than those without visual issues.

The brain regions responsible for vision and cognition are closely linked and vision loss can lead to reduced cognitive stimulation and increased social isolation. Many issues with vision, much like hearing, can be easily addressed.

Our sense of touch also provides essential feedback from our environment, and changes in tactile sensitivity may signal broader neurological issues. Reduced sensitivity to touch has been correlated with a higher risk of Alzheimer’s in some studies.

For example, one study examined individuals over a period of 11 years showed a 1.63-fold higher risk of dementia for those with a reduced ability to physically feel.

It is unclear whether increasing the amount you touch reduces the risk of cognitive decline but one intriguing study in newborns and children showed that those who were more often barefoot had better memory function.

Then there is smell. Most of the research looking at the dementia connection with this sense relates to whether a reduced ability to smell (anosmia) can be an early indicator of conditions that cause dementia, such as Alzheimer’s Disease.

The evidence is quite robust here and for some years clinicians used tests of smell (asking patients to identify different smells) as a way of assessing whether Alzheimer’s might be present.

There is also a fascinating link between smell and memory – I’m sure you have all experienced being transported back to a place you were many years ago simply by smelling something associated with the memory. For me, the smell of pine needles takes me right back to my grandparents’ garden, where, you guessed it, there were a series of small pine trees.

More research is needed to understand the connection with dementia and the senses, but while we wait for the answers, I would suggest striving to fully embrace the multi-sensory world around you.

Kailas Roberts is a psychogeriatrician and author of Mind your brain The Essential Australian Guide to Dementia now available at all good bookstores and online. Visit yourbraininmind.com or
uqp.com.au