  The leaves of the Coriandrum sativum plant, known as cilantro or coriander,
are widely used in many cuisines around the world. However, far from being a
benign culinary herb, cilantro can be polarizing---many people love it while
others claim that it tastes or smells foul, often like soap or dirt. This soapy
or pungent aroma is largely attributed to several aldehydes present in
cilantro. Cilantro preference is suspected to have a genetic component, yet to
date nothing is known about specific mechanisms. Here we present the results of
a genome-wide association study among 14,604 participants of European ancestry
who reported whether cilantro tasted soapy, with replication in a distinct set
of 11,851 participants who declared whether they liked cilantro. We find a
single nucleotide polymorphism (SNP) significantly associated with soapy-taste
detection that is confirmed in the cilantro preference group. This SNP,
rs72921001, (p=6.4e-9, odds ratio 0.81 per A allele) lies within a cluster of
olfactory receptor genes on chromosome 11. Among these olfactory receptor genes
is OR6A2, which has a high binding specificity for several of the aldehydes
that give cilantro its characteristic odor. We also estimate the heritability
of cilantro soapy-taste detection in our cohort, showing that the heritability
tagged by common SNPs is low, about 0.087. These results confirm that there is
a genetic component to cilantro taste perception and suggest that cilantro
dislike may stem from genetic variants in olfactory receptors. We propose that
OR6A2 may be the olfactory receptor that contributes to the detection of a
soapy smell from cilantro in European populations.
