Asparagus Officinalis Case Study

For over two thousand years, people have been cultivating and consuming Asparagus officinalis. During this time some people have observed a peculiar manifestation of an odd odor in their urine shortly after ingesting this vegetable (Mitchel and Waring 2014). This particular stench has been described as smelling like boiled cabbage (Mitchel et al. 1987, Pelchat et al. 2011). Many experiments have contributed this smell to sulfurous molecules found in the urine after asparagus ingestion, the most common molecules found being methanethiol and dimethyl sulfide (Lison et al. 1980, McDonald 2011, Mitchel et al. 1987, Mitchel and Waring 2014, Pelchat et al. 2011). It is thought that the digestion of the chemical compound 1, 2-dithiolane-4-carboxylic

1980, Pelchat et al. 2011). It was suggested first as a specific smell hypersensitivity by Lison et al. in 1980, meaning that the people that could smell the odor had a heightened sense of smell allowing them to distinguish the asparagus odor from regular urine odors. However, in the experiment conducted by Lison et al. (1980), there was not a big enough difference or variation between those that could smell the odor and those that could not smell it, these results do not have enough evidence to support that a specific smell hypersensitivity exists they simply show that each of the different subjects can smell the odor at varying concentrations of the diluted urine (Lison et al. 1980, McDonald 2011). The results of the experiment conducted in 1980 by Lison et al. could also be considered as inaccurate because they used a single urine sample for the experiment with unknown concentrations of the sulfurous compounds, the sample could have had a small concentration of the sulfurous compounds meaning only the most sensitive of noses could have registered the characteristic

2011). This hypothesis was put to the test by Pelchat et al. in 2011, who had volunteers donate both regular urine and asparagus urine, then presented the volunteers with samples of urine from all the volunteers to see whether or not they could detect the scent in the samples, of not just their own urine but in others as well. The results of this experiment revealed that six percent of the volunteers were unable to detect the asparagus odor in the urine samples, which highly suggests that there is an anosmia present for the asparagus odor. However, these results do not prove the anosmia because the urine samples used contained varying amounts of the sulfurous compounds meaning that some of the samples could have had ample amounts of the sulfur molecules while other samples could have had lesser amounts making it either easier or more difficult for the different subject’s to perceive the odor. Much like the experiment conducted by Lison et al. in 1980 this experiment really just proved that at varying concentrations different people can smell the odor. It did not present clear cut data that proved whether there really are “smellers” and “nonsmellers.”