Oregano - The mountain joy

Brief History

The species of Origanum, mostly cultivated for many centuries in the Mediterranean, Euro-Siberian, and Iran-Siberian regions belong to the same family (Lamiaceae) as basil, but their leaves and flowers have a completely different and characteristic odor and flavor. Nowadays, we can find them in most of the continents. The species of this family that are most commonly used for culinary purposes in Europe and US is the Origanum vulgare, although the species Coridohymus capitatu, Origanum onites and lately, the Cretan oregano, Origanum dictamnus, can also be found in the market. There are two other species of Origanum,  usually called as the Mexican oregano (Poliomintha longiflora and Lippia berlandieri) which are different in color, odor and flavor³. 

The name, Origanum, comes from the Greek words oros, which means mountain, and ganos, meaning joy, because this plant grows or is cultivated in mountainous regions and gives a pleasant feeling due to its odor and appearance. Many different species of oregano are used around the world, and the climate they grow plays a big role in the content of their essential oils and the chemical components that they contain and are important for our health.

Health benefits

Oregano has been associated with several medicinal properties: it is orexigenic (triggers appetite), antioxidant^{4, 9, 11-14, 21}, diuretic and digestive², emmenagogue², antispasmodic²², astringent and soothing for the nervous system².

Antiseptic

It has been shown in several studies that Oregano can inhibit the growth of bacteria, like the bacterium Helicobacter pylori, which causes gastritis in humans as well as fungi, like ringworms^{5, 6, 10, 15, 19, 20, 23}. Apart from that, it has also the ability to inhibit the growth of several parasites (anthelmintic activity) and even kill some human intestinal parasites^{7, 16, 17, 22}. Finally, the phytochemicals that oregano contains can suppress the growth of microorganisms which cause oral diseases and ear infections¹⁹.

Anti-inflammatory – Helps the immune system

Extracts of oregano have anti-inflammatory action¹⁹. There are several studies which showed that the oregano oil has a beneficial effect against inflammation and can help the immune system^{18, 19}. More specifically, the rosmarinic acid that is one of the constituents of the oregano oil, can induce the death of lymphocytes, T and natural killer cells, which are part of harmful immune responses, as well as reduce the symptoms of seasonal allergies. The essential oil of oregano has also been shown to reduce cytokine levels, which are normally high during inflammation.

Gastrointestinal disorders

There is more and more evidence that the phytochemicals oregano contains display properties beneficial for the health of the gut⁸. In a recent animal study¹ oregano was shown to be beneficial for the intestinal function and to shape the microbiome, by promoting the growth of beneficial bacteria, while reducing the growth of pathogenic bacteria.  The species Origanum dictamus, has also been evaluated from the European medicines agency (EMA/HMPC) as a safe traditional herb, especially for gastrointestinal disorders.  

Anti-oxidant – Protects from cancer

Due to its high phenolic content, oregano has a strong antioxidant capacity and can protect us from cancer or other chronic oxidative diseases, such as atherosclerosis, Alzheimer’s disease, Parkinson’s disease, diabetes, rheumatoid arthritis, chronic inflammation etc. Mainly the compounds carvacrol, γ-terpinene, rosmarinic acid, ursolic acid, protocatechuate-glycosides, and thymol are the most studied and promising ones¹⁹. In animal studies it has been shown that some of these compounds can protect the DNA molecules, and the cells from damage. They can increase the activity of enzymes that repair the damaged DNA, as well as inhibit cells from proliferating, something that happens during cancer. Rosmarinic acid specifically, was shown to block processes related to cancer metastasis, as well as skin inflammation¹⁹.

Recipes

1. Eggplant Imam 
2. Add dried oregano to your omelettes, Greek salad or dakos

Tips and tricks

• Store your dry oregano in a well closed container or bag, away from humidity, to maintain the aroma and the flavor.
• Add oregano to your food at the end of cooking in order to avoid bitter taste and to maintain all the healthy components that it contains.

References

1. Bauer B.W., Radovanovic A., Willson N.L., Bajagai Y.S, Hao van T.T., Moore R.J., Stanley D., Oregano: A potential prophylactic treatment for the microbiota, In Heliyon, 2019; 5, 10: e02626.
2. Bazaios, K., 100 Herbs for 1000 therapies, 1982, Athens.
3. Cid-Pérez T.S., … López-Malo A., in Essential Oils in Food Preservation, Flavor and Safety, 2016.
4. Couladis M., Tzakou O., Verykokidou E., Harvala C., Screening of some Greek aromatic plants for antioxidant activity, Phytother.Res., 2003; 17, 2: 194–195.
5. Daferera D.J., Ziogas B.N., Polissiou M.G., GC–MS analysisof essential oils from some Greek aromatic plants and their fungitoxicity on Penicillium digitatum, 2000, J.Agric.FoodChem, 48; 6: 2576–2581.