An Australian woman noticed her husband smelled differently, but dismissed it until after he was diagnosed with Parkinson’s Disease. Upon attending a lecture on Parkinson’s Disease, she recalled the experience and asked the lecturer what scent she might have smelled. Intrigued, researchers explained that the “slightly musky aroma” might be caused by changes in the composition of the oils on his skin. Upon investigation, the University of Edinburgh confirmed that she could not only identify her husband’s scent, but she could also detect the smell of other Parkinson’s patients from smelling their shirts (https://www.eveningtelegraph.co.uk/fp/joys-amazing-ability-tobe-featured-in-tv-show/).
While this woman exhibits extraordinary powers of smell, studies across species suggest females generally have greater olfactory sensitivity than males, including canines (http://emainehosting.com/mesard/Articles/Canine-Olfaction-Review%20-kab.pdf).
According to Medical News Today (https://www.medicalnewstoday.com/articles/284991.php), a research team at the Federal University of Rio de Janeiro in Brazil studied human brains of healthy people who were over the age of 55 years when they died. None of them were employed in jobs requiring an unusually good sense of smell. They found that the women’s brains had up to 50% more neurons in the olfactory bulbs than the men. This suggests that “more neurons in the female olfactory bulbs would provide women with higher olfactory sensitivity”.
Future medical research may help to understand how disease processes alter the chemical composition of scents, as well as gender differences in olfactory capabilities.