Is the ability of humans to sense smell changing?
Variations in the genes for the newly discovered scent receptors for musk and underarm odour add to a growing body of research suggesting that humans' sense of smell is gradually becoming less sensitive (PLOS Genetics).
Scientists can combine differences in scent perception with a person's genetics to discover the role of various scent receptors. In a new study, a team of researchers from the University of Chinese Academy of Sciences, Shanghai, China, screened genomes of 1,000 Han Chinese people to find genetic variations linked to how the participants perceived 10 different scents. Then they repeated the experiment for six odours in an ethnically diverse population of 364 people to confirm their results. The team identified two new receptors, one that detects a synthetic musk used in fragrances and another for a compound in human underarm odour, says release from PLOS.
In combination with previously published results, the researchers find that people with the ancestral versions (the version shared with other non-human primates) of the scent receptors tend to rate the corresponding odour as more intense. This supports the hypothesis that the sensitivity to smells of humans and other primates has degraded over time due to changes in the genes that code for our smell receptors.
