Cilantro is one of the most controversial, heavily debated herbs. To some individuals, it’s a refreshing and bright addition to any meal. For others, cilantro has a pungent soap flavor. This can be attributed to genetic differences between populations. More specifically, variations in taste and sensory receptors that influence overall sensory perception (Knaapila et al., 2012). The genes hypothesized to be involved in cilantro’s perceived taste are TRPA1, GNAT3, and TAS2R50 (Knaapila et al., 2012). This taste study was conducted on twins in order to determine if taste perception is attributed to genetic or environmental factors. I would say it embodies the autonomy biomedical value, as the research took volunteers who willingly consented to be studied. Therefore, autonomy was heavily considered in the experimental process.
My sister and I have opposing views on cilantro. She loves a good cilantro garnish, while I would prefer my food cilantro-less. This doesn’t seem odd, until you consider that we are monozygotic twins. Meaning, we should, for the most part, share fairly similar genomes. In the cilantro debate, this can only mean one thing. We have the soap gene and, therefore, my sister enjoys the taste of soap. Conversely, we don’t have the soap gene and I genuinely don’t like the taste of cilantro. However, it turns out there’s more to the cilantro controversy. Although monozygotic twins share mostly the same genes, there can still be some mutations that result in diversity. Also, it turns out that sensory perception is only partially explained by our genetic foundation. This adds some nuance to the argument. Maybe my sister does have the cilantro soap gene, but there are additional external influences that alter her perception of it. Another possible explanation is that one of us could have acquired a mutation, causing one to have the soap gene and the other one to lack it. Overall, I guess we can’t definitively prove that my sister enjoys the taste of soap, but I would argue that we also can’t prove that she doesn’t.
https://academic.oup.com/chemse/article/37/9/869/327642
https://www.npr.org/sections/thesalt/2012/09/14/161057954/love-to-hate-cilantro-its-in-your-genes-and-maybe-in-your-head
Great post Katie! I also don't like cilantro because it tastes like soap to me. I find it interesting that you both share similar genes, but have a mutation for certain things. I found a study where they hypothesized that food preferences are more influenced by the shared and unique environment than genetics in adolescent twins. 2865 twins from Britain rated their liking of certain food in different categories for 2 years. The results showed that shared environments do not influence food preferences in twins as they age, but genetics and unshared environments contribute to different tastes (Smith et al., 2016).
ReplyDeleteSmith, A. D., Fildes, A., Cooke, L., Herle, M., Shakeshaft, N., Plomin, R., & Llewellyn, C. (2016). Genetic and environmental influences on food preferences in adolescence. The American journal of clinical nutrition, 104(2), 446–453. https://doi.org/10.3945/ajcn.116.133983
Personally, I find cilantro very unpleasant to smell and taste, even though I am only a heterozygous for the TAS2R50 gene. With that being said, you have made a very interesting point mentioning the difference between you and Bella, your monozygotic sister, regarding your preferences for the herb. I came across the topic of epigenetic and the studies scientists performed on monozygotic twins to understand the field, which might explain your very opposite liking to cilantro.
ReplyDeleteBasically, epigenetic involves the changes of genetic expression in a person, not a mutation in the DNA sequence, that are caused by environmental factors. The thing that makes epigenetics interesting is that it emphasizes how susceptible we are to environmental agents during our development, since simple things such as chemical exposure, stress, love, affections, can cause irreversible and heritable changes to the way our DNA get methylated or not. This topic might also serve as the answers as to why one monozygotic twin dislikes cilantro and the other does not. Perhaps, the exposure that Katie experienced in the past increased her DNA histones methylation of in the region containing the TAS2R50 gene, causing transcription of that gene to be repressed. Or Bella experienced something that demethylated her DNA?
Li, S., & Hopper, J. L. (2021). Twin and family studies of epigenetics. Academic Press.
I enjoyed your post Katie. I personally don't mind the taste of cilantro, and it now makes sense as to why others refuse to have any of it. It was also interesting that you and your sister share different experiences with the taste of cilantro and sparked some reflection on other potential foods whose taste perception relies on the coding of genes. As it turns out there is a similar phenomena associated with Brussels sprouts. A chemical that our taste buds tastes for is a bitter chemical PTC (phenylthiocarbamide), and the receptor for this chemical is coded by the gene TAS2R38 which is very close to the cilantro gene TAS2R50. The gene for Brussels sprouts comes in 2 forms, bitter-tasting and non-tasting. Having 2 copies of the non-tasting gene will lead to no reception, one copy of each will lead to partial reception and so forth. So maybe you and your sister could try some Brussels sprouts and see if a similar situation arrises?
ReplyDeletehttps://www.centreofthecell.org/blog/science-questions/why-do-some-people-hate-brussels-sprouts/#:~:text=One%20type%20of%20these%20taste,TAS2R38%2C%20or%20the%20PTC%20gene.
Soap fan here. I love the taste of cilantro but my girlfriend hates it so our food is mostly cilantro less. I wonder if post-translational modifications such as methylation patterns could also explain the differences in gene expression in the case of the monozygotic twins. There have also been instances of people who have recovered from covid-19 that report cilantro now had the soap taste. Olfactory and gustatory receptors are both part of the g-protein coupled receptor family and both contribute to our sense of taste (Otte et al., 2020). Following covid-19 exposure, it would be interesting to see if there were modifications to the GPCR in either receptor type and if that contributed to the change in taste for cilantro.
ReplyDeleteOtte, M. S., Eckel, H., Poluschkin, L., Klussmann, J. P., & Luers, J. C. (2020). Olfactory dysfunction in patients after recovering from COVID-19. Acta oto-laryngologica, 140(12), 1032–1035. https://doi.org/10.1080/00016489.2020.1811999