Dogs have been observed to have the ability to sniff out the symptoms of low blood sugar in diabetic patients, but what exactly the pups are sniffing has remained a mystery.
But a new paper published gives a likely answer: people with low blood sugar smell different.
Medical detection dogs are increasingly being used to detect diseases such as diabetes and cancer. The BBC reported on the British charity Medical Detection Dogs, which trains dogs to watch over patients with various conditions. In March 2016, the Washington Post and others wrote about the dog Jedi, who reportedly detected a hypoglycemic attack in his 7-year-old owner while the boy slept — and while the boy's glucose monitor erroneously gave out normal readings.
It is important to point out that the study points out that much of the evidence for the use of dogs for medical detection is anecdotal, but it remains a promising field of research.
Hypoglycemia occurs in patients when there is too much insulin in the blood and not enough sugar, or glucose. Diabetes patients often suffer from hyperglycemia — a condition where there is excess sugar in the blood. This is typically because the pancreas is not producing enough insulin to process the glucose in the bloodstream. But sometimes diabetes patients can become hypoglycemic — if, for example, they do not eat enough after taking an insulin dose.
Now researchers from Cambridge University and the University of Oxford have found one chemical — called isoprene — that the dogs might be detecting, according to an article in Gizmodo discussing the research. For reasons still unknown, isoprene levels in human breath rise as blood sugar lowers, and it may be one of the chemicals, or the sole chemical, dogs are sensing.
The study was published in the July 2016 issue of the journal Diabetes Care.
"Dogs don't so much see the world as they do smell it," the article in Gizmodo notes, and they are capable of detecting chemical traces so minute, they might be compared to sniffing out a teaspoon of sugar in two Olympic-sized swimming pools.
The research could lead to the development of new medical sensors that can detect changing levels of these chemicals and warn patients about potential symptoms.