The sense of smell is most important in sensing danger. Smoke, poisonous gas, any familiar odour may help save your life at any given moment. As it turns out, the sharpness of this particular sense also helps to determine whether the grim reaper is near.
A study published in the open access journal, PLOS ONE revealed that a connection between losing the sense of smell and nearness of death has been proposed according to a study. This study, conducted by Jayat Pinto and his colleagues from the University of Chicago in 2005-6, included over 3000 participants between the ages of 57 and 85 from the National Social Life, Health, and Aging Project. The study asked the participants to identify 5 common smells (rose, fish, orange, peppermint and leather). The severity of smell loss was measured by the number of smells not identified.
After five years the team tracked down as many of the original participants as they could for a repeat of the test and found that 430 (12.5%) of them had died. 39% of those who had failed the original test had died before taking the second test, 19% of those who had moderate scores had died and of the ones who had passed the original test, 10% had kicked the bucket.Smell loss proved to be a greater indicator of death than diagnosis of cancer, heart failure and lung disease but the researchers stressed that it is only a strong indicator not a cause. Two reasons for this are that the olfactory nerve is constantly repaired by stem cells. Smell loss is an indicator that the repair is slowing down, hence bodily function is deteriorating; also smell loss means that poisonous gases and smoke and harmful substances may find their way in to the body without identification.