Smell and Disease

 by Bianka Anszczak

Image by Genia Brodsky and Noam Sobel (Wiki)

Today, if you feel unwell, doctors are more likely to give you a diagnosis after running blood tests etc, rather than give you a whiff. Now although smelling like body odour might just be because you forgot to put on deodorant that morning, our bodies produce different smells for different diseases.

Joy Milne, the ‘super-smeller’, realised she could smell Parkinson’s when she went to a Parkinson’s support meeting, and everyone smelled like her husband – who was diagnosed years prior.

After consulting doctors about this, a study was conducted. They decided to test this by giving her t-shirts (some worn by people with the disease, and others which were controls) Joy ended up identifying all but one correctly. Now you may think this is impressive, but what if I told you that the one control which she identified as incorrect, was later also diagnosed with Parkinson’s.

Now you may be thinking how is this possible!?

Allow me to introduce you to… Man’s best friend.

Dogs are famously known for their incredible sense of smell. Compared to humans measly 5 million, dogs have 220 million sent receptors! This is thanks to their genetics and physiology, providing them with many more olfactory nerve cells, equipping them as perfect sniffers. To put into perspective just how good their sense of smell really is, it is like finding a single drop of liquid from 20 Olympic-sized swimming pools, that is equivalent to 1/trillion.

Over the decades, we have taken advantage of their incredible sense of smell to hunt, detect explosives, drugs and now diseases.

To name a few, dogs have been proven to successfully detect: Cancer, Diabetes, Epilepsy, Malaria, Parkinson’s and many more.

So why do diseases smell? And why is it good?

Body odour is a complex cocktail of compounds, but simply put, our bodies release these odorous compounds as part of metabolic processes. Pathogens and microbes also alter the way we smell.

Through detection of diseases via smell, it could lead to more early diagnosis in patients, giving doctors a better chance at treating the disease. Moreover, it will help minimise the number of invasive ways of identifying a disease, perfect for someone who fears needles like myself.

However, introducing disease detection dogs to clinical settings, has been questioned as ‘being sniffed and barked at by a cancer detection dog on a at a general check-up may be unnerving to some individuals.’

Hence why, researchers have explored the Electronic Nose. And it is just as cool as it sounds, it would create a VOC profile of the sniff sample – like humans or dogs – but instead display it on screen, allowing doctors to see whether a person is indicating a certain disease.

And so, although there have been substantial leaps in olfaction research, there is still a great deal of potential for the future of medical diagnostic technology.