New research suggests changes in the smell of your urine could be a biomarker for dementia.

It’s probably not the first thing you’d think of checking when trying to diagnose the early stages of dementia, but changes in the odour of someone’s urine could be a sign of changes in the brain that could lead to Alzheimer’s disease.

That’s what researchers from the US Department of Agriculture and the Monell Chemical Senses Centre are claiming in a new study carried out on mice.

Currently, the only truly accurate way of diagnosing dementia is through a post-mortem examination of the brain. However, doctors can usually pinpoint the condition through other symptoms such as memory loss, loss of speech and other behavioural issues.

However, researchers believe that a unique smell appears just before significant changes start to occur in the brain of someone with dementia. This means that by detecting a particular scent biomarker at this stage could allow for an earlier diagnosis and a swifter implementation of treatment.

Study author Dr Bruce Kimball said,

‘Previous research… has focused on body odour changes due to exogenous sources such as viruses or vaccines.

‘Now we have evidence that urinary odour signatures can be altered by changes in the brain characteristic of Alzheimer’s disease.

‘This finding may also have implications for other neurologic diseases.’

Study co-author Dr Daniel Wesson, of Case Western Reserve University School of Medicine, said,

‘While this research is at the proof-of-concept stage, the identification of distinctive odour signatures may someday point the way to human biomarkers to identify Alzheimer’s at early stages.’

However, it’s worth remembering that this study was carried out on mice, which have been bred to mimic the brains of Alzheimer’s-related brains, and not on human study participants. The study found that the urinary odour profiles of mice with Alzheimer’s were different to the mice in the control group.

Dr Doug Brown, director of research at Alzheimer's Society, advises caution on studies such as this.

‘The test was carried out on genetically altered mice, which do not fully replicate several of the important changes seen in the brains of people with dementia, so we cannot yet predict that we will see the same urine changes in people.

‘Although this is an interesting approach to the problem of identifying Alzheimer’s before memory symptoms appear, it is too early to tell whether this could be a valid way to diagnose the condition in people.’

In other words, while this study gives a certain level of hope, we wouldn’t recommend spending ages trying to sniff your urine…

For more information on the early signs and symptoms of dementia, click here.