Can you smell sweat?

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Genetic Elucidation of Human Hyperosmia to Isovaleric Acid (Open Access):

Humans can accurately discern thousands of odors, yet there is considerable inter-individual variation in the ability to detect different odors, with individuals exhibiting low sensitivity (hyposmia), high sensitivity (hyperosmia), or even “blindness” (anosmia) to particular odors. Such differences are thought to stem from genetic differences in olfactory receptor (OR) genes…which have both functional and inactive alleles in the population…Here, we provide evidence that a particular segregating OR gene is related to sensitivity to a sweaty odorant, isovaleric acid. We show that hypersensitivity towards this odorant is seen predominantly in individuals who carry at least one copy of the intact allele. Furthermore, we demonstrate that this hyperosmia is a complex trait, being driven by additional factors affecting general olfactory acuity. Our results highlight a functional role of segregating pseudogenes in human olfactory variability, and constitute a step towards deciphering the genetic basis of human olfactory variability.

PLoS also has a nice write up for the lay audience, with a more frank title.

Related: A universal olfactory aesthetic?, A world of sensory difference, PTC taste, balancing selection?, PTC, part II, Taste & behavior genetics, Genetics of taste and Slow & diverse food.

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8 Comments

  1. from Plos “Women in the study showed somewhat better sensitivity than the men, but age, smoking habits, and ethnic origin did not affect the results.” Aren’t surprising results fascinating? Smoking and age have no effect; I’d have lost a bet on that. One caveat: would smoking and age have been self-reported, or would they expect factual information?

  2. Neat! 
     
    ethnic origin did not affect the results 
     
    The participants ran the gamut of ethnicities from Ashkenazi to Sephardi to mixed. Not surprising. From the big recent selection papers, we know that genes involved in olfaction consistently show signals of recent selection, usually different across groups.

  3. Hmm, Haplotter says OR11H7P doesn’t show signs of recent selection. The Fst suggests a diff between Africans and Asians, but don’t know if it’s significant.

  4. I wonder if more investigation might discover ethnic differences. There are big ethnic differences in apocrine sweat gland density and activity. Perhaps there are complementary ethnic differences in olfactory perception.

  5. Is it true that many East Asians, Koreans in particular, have no apocrine glands? What does that mean for pheromone production?

  6. In my youth I briefly had a Japanese gf who, uh, really enjoyed nuzzling into my armpit. It was curious back then, but even more so now.

  7. Interesting, Dumb-Dumb. My Thai wife often has her nose close to my armpits. 
     
    About sensitivity to odors: not only do I have a very weak sense of smell, but a lot of the few things that I can detect smell like alcohol to me.

  8. smelliness & smell-ability (or lack of) seems the sort of “coupled” traits which might be the target of sexual selection.

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