Asparagus Odor Detection & Genetics

How it works

Ever noticed your urine smells different after eating asparagus? You’re not the only one.

The genetic link 

23andMe researchers identified a genetic marker located near the OR2M7 gene that is associated with the likelihood of smelling asparagus-related odor in their urine. This gene has instructions for a protein that detects odor molecules. 

What causes the smell?

Scientists believe the smell comes from molecules the body makes when it breaks down the asparagus. One of these molecules contains sulfur and has an odor like cooked cabbage. 

Did you know?

The skin lining your nose contains nerve cells that are covered in molecular sensors, called “olfactory receptors.” These receptors specialize in detecting odor molecules. Humans can detect thousands of different scents using various combinations of more than 300 olfactory receptors. And the types of olfactory sensors you have determine what you can and cannot smell. 

Learn more  

Got a whiff of your genetics and want to learn more? Pick up a 23andMe DNA kit to see what your genes have to say about asparagus odor detection and other interesting traits. 

References

Bushdid C et al. (2014). “Humans can discriminate more than 1 trillion olfactory stimuli.” Science. 343(6177):1370-2. 

Eriksson N et al. (2010). “Web-based, participant-driven studies yield novel genetic associations for common traits.” PLoS Genet. 6(6):e1000993. 

Lison, M et al. (1980). “A Polymorphism of the Ability to Smell Urinary Metabolites of Asparagus.” Br Med J 281 (6256):1676–78. 

Logan DW (2014). “Do you smell what I smell? Genetic variation in olfactory perception.” Biochem Soc Trans. 42(4):861-5. 

Malnic B et al. (2004). “The human olfactory receptor gene family.” Proc Natl Acad Sci U S A. 101(8):2584-9. 

Mitchell SC. (1987). “Odorous Urine Following Asparagus Ingestion in Man.” Experientia 43(4):382-3. 

Mitchell SC. (2001). “Food Idiosyncrasies: Beetroot and Asparagus.” Drug Metab Dispos. 29(4 Pt 2):539–43. 

Pelchat ML et al. (2011). “Excretion and perception of a characteristic odor in urine after asparagus ingestion: a psychophysical and genetic study.” Chem Senses. 36(1):9-17. 

Weimer B et al. (1999). “Sulfur metabolism in bacteria associated with cheese.” Antonie Van Leeuwenhoek. 76(1-4):247-61.