Studies on 3,000 people aged 57-85 who were asked to identify 5 common smells (rose, fish, leather, orange and peppermint) found that those who were unable to correctly identify any of the 5, almost all of them went on to develop dementia within 5 years as did nearly 80% of those who only got one or two correct. This is because the part of the brain that controls smell (the olfactory bulb) is one of the first to be affected by dementia.
“These results show that the sense of smell is closely connected with brain function and health. We think smell ability specifically, but also sensory function more broadly, may be an important early sign, making people at greater risk for dementia.”
Of the 5 senses, smell is the one that we may not take as seriously until we lose it, as we can function without it but according to research in 2014, loss of smell was associated with an increase in early death within 5 years. According to the study it was a better predictor of death than being diagnosed with heart failure, lung disease or cancer.
Being unable to smell can affect someone’s wellbeing, mental health, nutrition and lifestyle and Professor Pinto states it can be linked with depression as people don’t get as much pleasure from life. Not being able to smell is definitely worth taking more seriously.
The findings are really interesting and something that Alzheimer's Research UK are looking at to understand more about the link between changes in smell, ageing and dementia. They also stated that smell tests need to be used with more specific tests to help detect dementia earlier in the future.
Interesting times, and fingers crossed more research and findings are available in the future.