Two Unifactorial Characters for which Man is Polymorphic

  title={Two Unifactorial Characters for which Man is Polymorphic},
  author={Anthony C. Allison and Kennedy Mcwhirter},
IT has been recognized for many years that humans excrete methanethiol (methyl mercaptan) after eating asparagus, and it has been assumed that this character is universal1,2. We have found, however, that while some subjects excrete detectable amounts of methanethiol after ingesting only three or four sticks of asparagus, no significant amount of the compound appears in the urine of others after ingestion of as much as a pound of asparagus. Biochemical investigations of this metabolic difference… Expand
Race Differences in the Ability to excrete Beetroot Pigment (Betanin)
A study of the frequencies of betanin excretors among different racial groups found a great deal of variation was observed in the intensity of the red tint in the urine of the excretor. Expand
A polymorphism of the ability to smell urinary metabolites of asparagus.
Thresholds for detecting the odour appeared to be bimodal in distribution, with 10% of 307 subjects tested able to smell it at high dilutions, suggesting a genetically determined specific hypersensitivity. Expand
Metabolic Polymorphisms in Mammals and Their Bearing on Problems of Biochemical Genetics
Examples of chemical differences between different members of a single mammalian species are reviewed and there is suggestive evidence that other metabolic polymorphisms may also be subject to selection. Expand
New medicine and new biology.
Olfactory genetics and anosmia: a clue to the olfactory code in normal man and in patients with advanced adrenal cortical insufficiency. Expand
Excretion and Perception of a Characteristic Odor in Urine after Asparagus Ingestion: a Psychophysical and Genetic Study
It is concluded that individual differences exist in both odorant production and odor perception, and the biological basis for the inability to produce the metabolite in detectable quantities is unknown. Expand
Food idiosyncrasies: beetroot and asparagus.
  • S. Mitchell
  • Biology, Medicine
  • Drug metabolism and disposition: the biological fate of chemicals
  • 2001
Two examples, where the population appears divided in its ability to process food products or more precisely the chemicals contained within them, are reviewed in detail in this article. Expand
Occurrence of S-methyl thioesters in urines of humans after they have eaten asparagus.
S-Methyl thioacrylate and S-methyl 3-(methylthio)thiopropionate were identified from methylene chloride extracts of such urines and appear to be the odor-causing compounds. Expand
The chemical nature of the urinary odour produced by man after asparagus ingestion.
The possible roles of S-methylmethionine and asparagusic acid as precursors of these odorous substances are discussed in relation to the known chemistry of the vegetable. Expand
Sniffing out significant “Pee values”: genome wide association study of asparagus anosmia
A large proportion of people have asparagus anosmia, and genetic variation near multiple olfactory receptor genes is associated with the ability of an individual to smell the metabolites ofAsparagus in urine. Expand
Odorous urine following asparagus ingestion in man
The production of odorous urine after the ingestion of asparagus has been shown to occur in 43% of 800 volunteers investigated and is reproducible over a 12-month-period. Expand