Scientists can now detect diseases by smell


For nearly the past decade, Israeli scientist Hossam Haick has been working on a device that some have called an “electronic nose.” His goal was lofty: He wanted to invent a medical device that could detect cancer early via the smell of a patient’s breath.

A study just published in the journal American Chemical Nanosociety suggests that not only can such a device work, but it is applicable to far more than one disease.

The study used breath samples collected from 1,404 people from 2011 to 2014 and was written by scientists from Israel, the United States, Latvia, China, and France. The test subjects were either known to be healthy or to be suffering from one of 17 diseases, including eight different types of cancer, Crohn’s disease, irritable bowel syndrome, and multiple sclerosis. The sensors make use of artificially intelligent nanoarrays (extremely small sensor points capable of identifications at a molecular level).

Other recent studies concluded that individual diseases can be predictably “smelled” by such sensors: A study published at the end of September found preeclampsia (a pregnancy-related complication characterized by high blood pressure) was detectable with up to 84 percent accuracy in “real world,” clinical conditions.

The theory that disease is detectable on our breath (and also our urine) dates back to Hippocrates. But the innovations of the past few years have found conclusively that each disease has its own “breathprint,” as Dr. Haick calls it. “We have a mixture of compounds which characterize a given disease,” he told Smithsonian Magazine, “and this picture is different from one disease to another.”

The study further identified 13 distinct chemical species, called volatile organic compounds, that are associated with certain diseases. Once particles in a person’s breath are exhaled, they can be identified, characterized, and associated with each particular disease. The results of each disease identification by the nanosensor were independently confirmed by other methods to ensure accuracy.

Dr. Haick began his research working on early identification of lung cancer, and he developed a breathalyzer-style device that he said was up to 90 percent accurate in diagnosing malignant lung cancer tumors. A commercial device is currently in testing for market, developed by Haick and the Israel Institute of Technology, that identifies strep throat and the flu using the same technology. He said he started with lung cancer because it’s very treatable in early phases, but most people don’t notice something is wrong until later, more fatal stages. Lung cancer can take years from onset of the growth of a tumor until it is detected, making it one of the least survivable cancers primarily because it is diagnosed so late. About 40 percent of people diagnosed with lung cancer are already in Stage IV of the disease. Haick’s sensors seek to identify the disease early, which would make it a life-saving device for hundreds of thousands of people every year.

The new study generalizes the device for a wider array of applications and has allowed practitioners to begin to map the breath prints of different diseases. The study concludes that, though at least years away, they would potentially be “easy-to-use, inexpensive (affordable), and miniaturized tools that could also be used for personalized screening, diagnosis, and follow-up of a number of diseases, which can clearly be extended by further development.” One thing is for sure: They already have way better odds than a dog does of smelling your cancer.