The guava is one of my favourite fruits, and one that, particularly represents this time of year here in Israel. Walk through any vegetable market, or ride the bus with people carrying their shopping and the guavas will soon make their presence known. I feel very sorry for those unfortunate souls who hate the smell

The guava, Psidium guajava, is tree in the Myrtaceae family, along with myrtle, eucalyptus clove and allspice, all with powerful but very different fragrances. The guava fragranceseems to be due mostly to a sesquiterpene called β-caryophyllene that is also found in the essential oils of cloves, black pepper, rosemary, cannabis and hops. The distinctiveness of the guava smell is due to other aromaticphytochemicals present.

Caryophyllene has interesting bioactivities. It activates the cannaboid-2 receptor (CB2), and is thus able to interrupt pathways of pain and inflammation. This may explain the use of clove oil to relieve toothache.

The guava is native to central America, but has spread to tropical and subtropical parts around the world, primarily for the edible fruit and its juice. Different parts of the guava plant are used as ethnic medicines for a number of a variety of disorders (see Gutiérrez et al, 2008), including those of the digestive and respiratory systems.

A focus of Guava medicinal use is for treating disorders of the mouth and teeth. Alam A et al (2023) showed that guava leaf extracts are antimicrobial towards against oralpathogens Candida albicans and Streptococcus mutans. Their extracts also acted against cells responsible for oral cancer. Some of these bioactivities they attribute to β-caryophylleneand D-limonene, the main constituents, though essentialoil they used also contained dozens more phytochemicals that may also have contributed to the bioactivities observed.

Guava extracts are marketed widely as food supplements, fragrances and flavourings. Personally, I like the fresh fruit best and enjoy guava season every year.

Further reading

🍈Gutiérrez RM, Mitchell S., Solis RV (2008). Psidium guajava: a review of its traditional uses, phytochemistry and pharmacology. J Ethnopharmacol. 117(1), 1–27. https://doi.org/10.1016/j.jep.2008.01.025

🍈 Alam A et al (2023). Composition, Antibacterial Efficacy, and Anticancer Activity of Essential Oil Extracted from Psidium guajava (L.)Leaves. Plants (Basel), 12(2), 246. https://doi.org/10.3390/plants12020246

🍈 Wikipedia (2023). Caryophyllene. https://en.wikipedia.org/w/index.php?title=Caryophyllene&oldid=1172904664

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