Strangely enough, researchers suggest that your sense of smell may provide hints about your time of death. Focusing on olfactory dysfunction as a sign of mortality, a 2014 study claimed that loss of smell is a more strong predictor of approaching death than lung disease, cancer, or heart failure.
Lead author Dr. Jayant Pinto compares losing smell to a canary in a coal mine—an early warning sign of underlying medical problems. Having 3,005 older U.S. adults identify five scents—peppermint, fish, orange, rose, and leather—the study evaluated their olfactory capacity.
Of the participants with accurate identification, 78% had normal smelling ability; 20% with two or three right identifications had substantial smell loss; and 3.5% straining to identify any or only one scent showed notable loss. Of the dead people, 39% had showed a notable loss of smell after five years, implying a relationship between olfactory impairment and mortality.
Although the injured olfactory system alone does not lead to death, researchers hypothesize that a diminished ability to smell could point to a decrease in the body’s capacity to restore important components, so perhaps contributing to mortality by other causes. According to the study, olfactory impairment may indicate either slower cellular regeneration or the cumulative consequences of environmental exposures over years.