Smell test can detect Alzheimer’s disease, scientists find

Researchers were able to tell the difference between the smell of urine in normal mice and mice that had been genetically altered to model aspects of Alzheimer’s. The findings may also be useful in detecting other neurological diseases.

Urine tests are normal for screening drug and pregnancy, and soon there might be a day when they will tell you if you’ll suffer the neurodegenerative disease Alzheimer’s.

The study, developed by a team of researchers from Philadelphia, the National Wildlife Research Center and the Case Western Reserve University School of Medicine, focused on developing a way to test for Alzheimer’s based on the smell of the patient’s urine.

Now US scientists have found the disease leaves an odour biomarker in urine well before the significant development of other Alzheimer-related problems.

The initial experiments were performed on mice. There is no test to definitively diagnose Alzheimer’s disease in living persons.

As there are no curative treatments for Alzheimer’s yet, the key is to detect the disease early so that families may plan ahead and seek appropriate symptomatic care for their loved ones. They gave the mice oral doses of an inhibitor that blocks CSF1R and found that it could prevent the rise in microglia numbers seen in untreated mice as the disease progressed.

Published in the journal Scientific Reports, the study looked at three separate mouse models, known as APP mice, which mimic Alzheimer’s-related brain pathology.

Dr Diego Gomez-Nicola, lead author of the study and an MRC New Investigator Research Grant (NIRG) fellow at the University of Southampton, said: “These findings are as close to evidence as we can get to show that this particular pathway is active in the development of Alzheimer’s disease”.

Using both behavioural and chemical analyses, it was found each strain of APP mice produced urinary odour profiles that could be distinguished from those of control mice.

Despite the fact that the most recent tests for Alzheimer’s disease in humans are not very precise, mostly due to the fact that the specific errant proteins associated with it aren’t detectable until having deposits in the brain, it would seem like the new technique might have some merits.

Findings revealed that changes in odor resulted in a different combination of compounds in the urine when compared to control mice without the genetic changes.

The researchers note that extensive studies are needed to identify and characterize Alzheimer’s-related odor signatures in humans.

The study, though, further supports previous research that an overactive immune system leads to chronic inflammation, which has been linked to Alzheimer’s, writes The Huffington Post. The team argues that the odour is related to the presence of an underlying gene rather than changes to the brain.