Giorgio Samorini

Giorgio Samorini is an Italian ethnobotanist specialized on psychoactive plants and mushrooms. He developed field research among native groups of Africa, Asia and Americas. He authored many scientific papers and books published in different languages.
Giorgio Samorini

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In recent years, a small group of researchers from different disciplines, including myself, has been highlighting a set of data that, not only does not confirm the millenary use of ayahuasca, but would demonstrate the contrary; that is, they would endorse a rather recent discovery, someone proposing only few centuries. In response to this new hypothesis, there are many protests against me (in Italy and elsewhere) and other researchers on the part of modern religious, neo-shamanic, and New Age movements that have sentimental (if not economic) interests to endorse the great antiquity of the visionary drink they employ in their rituals. I respond to these protests with the consideration that this possible recent discovery would take nothing away from the importance and profound sacramental value of this visionary drink. One could only give a happy welcome to such a recent conquest by the traditional world, proving itself to still be able, despite the imposed Western influence, to create such cultural jewels.

In this article, I offer a critical analysis concerning the few archeological data that have been associated to ayahuasca, showing how this visionary brew has been “victim” of fakes that are still repeatedly proposed, even in the academic field.

In this article, I offer a critical analysis concerning the few archeological data that have been associated to ayahuasca, showing how this visionary brew has been “victim” of fakes that are still repeatedly proposed, even in the academic field. A common, widespread idea concerns the great antiquity of this visionary drink, reaching back 5000–6000 years. This idea originated from a script by the Ecuadorian anthropologist Plutarco Naranjo, dated 1986,1 who, observing how the preparation of the ayahuasca drink requires the prolonged decoction of its vegetable ingredients, deduced that it could only have occurred after the invention of pottery, whose oldest finds in South America, belonging to the prehistoric Valdivia culture of Ecuador, are nowadays dated to 4400 BC. This dating was later arbitrarily and uncritically regarded as the moment of the origin of ayahuasca.

This is also due to imaginative interpretations of the same anthropologist, who wanted to see certain “wizard’s vases” (ollas de brujo) of the ancient Ecuadorian cultures as irrefutable ceremonial containers for the ayahuasca brew, as he wanted to see in some figurines—depicting men or gods with the phallus erect or taken up in the act of masturbating—as the testimony of a cult of the phallus associated with the ritual intake of ayahuasca. This interpretation is hardly acceptable, as it is not found at an ethnographic level and suffers from obvious Western interpretative extrapolations of an obsolete Freudian mold.

In this critique, I might add the fact that it is not true that ayahuasca requires a long decoction, although this is the most widespread practice. There are reports from the Colombian Putumayo—which I have recently confirmed in the field—of cases of cold drink preparation, leaving the fibers of the two vegetable ingredients to macerate in unheated water; simply performing a periodic mixing operation of the concoction.

If, in the case of these archaeological finds from Ecuador, it is easy for anyone to understand the unreliability of the theses proposed by Plutarco Naranjo, the critical analysis of another archaeological find—the one identified by the Chilean team of Juan Ogalde—2 3 requires a set of knowledge, especially biochemical, that is not available to everyone, and which I present here.

In two mummies—corresponding to a child of one year of age and to an adult man—harmine, one of the beta-carboline alkaloids present in the liana of ayahuasca (Banisteriopsis), was found.

The Ogalde team analyzed the hair of several mummies dated to the Middle Tiwanaku Period, found during the archaeological excavations in the Azapa Valley, located in the extreme north of Chile. In two mummies—corresponding to a child of one year of age and to an adult man—harmine, one of the beta-carboline alkaloids present in the liana of ayahuasca (Banisteriopsis), was found. From this, Ogalde concluded that the presence of harmine was a certain indication of consumption of the Banisteriopsis liana, since it is the only vegetable source in South America that produces this alkaloid, and its use in the Valley of Azapa would demonstrate an extensive commercial network, with the import of this plant from the areas of the Amazon more than 800 km away.

It could be pointed out that there is no need to look at the distant Amazon for the supply of Banisteriopsis, as the area of natural diffusion of this liana reaches the Bolivian plateau to the south;4 “only” 250–300 km away from the Chilean valley of Azapa. One could smile, also, at the erroneous statement given by Ogalde et al.5 that the mushroom Amanita muscaria produces tryptamines, revealing a certain degree of ignorance concerning psychoactive plants. But it is more important to counter that it is not true that Banisteriopsis is the only South American plant that produces harmine.

Personally, I counted about 30 South American plants known to produce harmine, and some in significant quantities.

Personally, I counted about 30 South American plants known to produce harmine, and some in significant quantities. Among these, 25 species of Passiflora,6 several of which spread to Peru and Argentina. Another harmine-producing plant is Tribulus terrestris, a ubiquitous species on several continents, also present in northern Chile7 and in Peru. In this last nation, where it is popularly called abrojo, anocar cchapi and estrella-casha, it is used in traditional medicine as a diuretic (Soukoup, 1970). Another source of harmine are the dried walnuts of Anacardium occidentale, the common cashew, originating in the northeastern regions of Brazil.8

But there is another harmine-bearing plant that more closely affects the geographical area and the chronology related to the mummies studied by Ogalde: It is Oxalis tuberosa Molina, a well-known culture of the Andean regions, popularly called oca, apilla, cuiba, whose tubers have been an important food source for Andean populations since prehistoric times. This plant does not produce seeds, but is reproduced by propagating its tubers. The absence of seed production is indicative of a great antiquity in its cultivation, and indeed, genetic studies have shown that this species was originally created by humans following the cultivation and selection of wild Oxalis species.9

The roots of this plant exude a compound that Bais et al.10 determined to be a mixture of harmine and harmaline. Although the Bais team subsequently retracted the results of their 2003 publication, for apparent reasons of protocol irregularities,11 other scholars have confirmed the presence of harmine and harmaline in the radical parts of O. tuberosa, and also inside its tuber.12

It is important to observe that this tuber is found in the Andean archaeological excavations, including those that came to light in the northern region of Chile, i.e., in the same area as the mummies studied by Ogalde (for a review of these archaeological findings see Samorini13) Probably, the most decisive datum concerns the presence of O. tuberosa precisely in the Valley of Azapa during the Middle Period, which corresponds to the Tiwanaku occupation phase; therefore, to the same chronological phase of the mummies studied by Ogalde.14

These data confirm—in contrast to the unreliability of the hurried deductions of the Ogalde team—the presence of a food source containing harmine in the same chronological and geographical context of the two mummies of the Azapa Valley in whose hair harmine was found. Assuming that this presence was caused by the intake of some vegetable, it is more likely that the food tuber of O. tuberosa, rather than the distant Banisteriopsis liana, was responsible for this.

But, there is more: The presence of harmine in hair and other biological tissues, both ancient and modern, may be due to exogenous and endogenous factors that do not involve the assumption of a direct source of harmine. It is a long-standing fact that, in different protein foods cooked  at high temperatures, simple beta-carbolines are formed; above all, harman, and harmaline. Fried or grilled meat and fish contain the highest concentrations of these compounds,15 which are also present in smoked foods,16 and in tobacco smoke.17 For example, harmine, together with harmaline and harman, are formed in grape wine, in cereal beers and in other fermented wines,18 due to specific chemical reactions of fermented alcoholic beverages. It is therefore very probable that they are also formed in fermented South American beverages, such as maize chicha, chicha de molle, and cauím, whose use in ancient Andean populations is well documented by archeology.19

But there is a further possibility for the presence of harmine in biological tissues, which does not necessarily entail the external introduction of this compound, and that is through the metabolization in the human body of different beta-carbolines, including harmaline and harman. Laboratory studies have shown that 13% of the harman absorbed in the body of a mammal is transformed into harmine,20 and also, harmaline is partly transformed into harmine.21 It is therefore possible that harmaline and harman, introduced into the body through plants, food, tobacco smoke, and alcoholic beverages, are, in part, metabolized in harmine, that, when recirculated, can then be fixed in the hair.

I have shown that the presence of harmine in biological tissues may be due to a set of factors, both exogenous and endogenous, and is not an exclusive indication of intake of Banisteriopsis.

With this, I believe I have shown that the presence of harmine in biological tissues may be due to a set of factors, both exogenous and endogenous, and is not an exclusive indication of intake of Banisteriopsis. If hair analysis should be carried out in search of beta-carboline alkaloids—including harmine—in different types of modern men, from smokers to alcoholic drinkers, to consumers of fried and barbecued foods, there could be some surprising results. And indeed, Ogalde’s team, in their analysis of Chilean mummies’ hair, used hair samples from three modern individuals as control data, including a 12-year-old teenager and his 45-year-old mother. These last two were also positive for harmine; this has been explained by the use, by both, of the same hair dye containing harmine!

A third archaeological fact that claims to demonstrate an ancient use of Banisteriopsis remains to be taken into consideration: that of the international team of Melanie Miller,22 concerning the recent discovery in a Bolivian site, dated to around 1000 AD, of a small bag whose chemical analyzes would have corroborated the ancient presence of five psychoactive sources; among these was included the Banisteriopsis liana, as a result of the determination of harmine. The critical analysis of this finding is still being studied by other scholars and myself, so I will not pronounce a conclusion at the moment.

The fact remains that, in the lists I recently published23 24 of the most ancient archaeological dates referring to the human use of the main intoxicating sources of the world, I excluded ayahuasca, both as a liana and as a drink, not believing reliability of the archaeological data that I have described and critically analyzed above (for the problem of the antiquity of ayahuasca, see also25).


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  1. Naranjo, P. (1986). El ayahuasca en la arqueología ecuatoriana (Ayahuasca in Ecuatorian Archeology). América Indígena, 46(1), 117–127.
  2. Ogalde, J. P., Arriaza, B. T., & Soto, E. C. (2009). Identification of psychoactive alkaloids in ancient Andean human hair by gas chromatography/mass spectrometry, J.Arch.Sci., 36, 467–472.
  3. Ogalde, J. P., Arriaza, B. T., & Soto, E. C. (2010). Uso de plantas psicoactivas en el Norte de Chile: evidencia química del consumo de ayahuasca durante el Periodo Medio (500–1000 d.C.) (Use of psychoactive plants in northern Chile: Chemical evidence of ayahuasca consumption during the Middle Period (AD 500–1000) Latin American Antiquity, 21(4), 441–450.
  4. Gates, B. (1982). Banisteriopsis, Diplopterys (Malpighiaceae). Flora Neotropica Monograph N. 30. New York City, NY: New York Botanical Garden.
  5. Ogalde, J. P., Arriaza, B. T., & Soto, E. C. (2010). Uso de plantas psicoactivas en el Norte de Chile: evidencia química del consumo de ayahuasca durante el Periodo Medio (500–1000 d.C.) (Use of psychoactive plants in northern Chile: Chemical evidence of ayahuasca consumption during the Middle Period (AD 500–1000)) Latin American Antiquity, 21(4), 441–450.
  6. Abourashed, E.A., Janderplank, J., & Khan, I. A. (2003). High-speed extraction and HPLC fingerprinting of medicinal plants. II. application to harman alkaloids of genus Passiflora. Pharm.Biol., 41(2), 100–6.
  7. Muñoz Pizarro, C. (1959). Sinopsis de la flora chilena: Claves pára la identificación de familias y géneros. (Synopsis of Chilean flora: Keys to the idenfication of families and genres) Santiago, Chile: Universidad de Chile.
  8. Tsuchiya H., Hayashi, H., Sato, M., Shimizu, H., & Iinuma, M. (1999). Quantitative analysis of all types of beta-carboline alkaloids in medicinal plants and dried edible plants by high performance liquid chromatography with selective fluorometric detection. Phytochem.Anal., 10(5), 247–253.
  9. Emshwiller, E., & Doyle, J. J. (2002). Origins of domestication and polyploidy in oca (Oxalis tuberosa, Oxalidaceae). 2. Chloroplast-expressed glutamine synthetase data, Am.J.Bot., 89(7), 1042–56.
  10. Bais, H. P., Vepachedu, R., & Vivanco, J. M. (2003). Root specific elicitation and exudation of fluorescent beta-carbolines in transformed root cultures of Oxalis tuberosa. Plant Physiol.Biochem., 41(4), 345–353. DOI: 10.1016/S0981-9428(03)00029-9
  11. Retraction notice (2010). Retraction notice to: Exudation of fluorescent beta-carbolines from Oxalis tuberosa L. roots, Phytochem., 71(1), 123
  12. Bocanegra, C. et. al., (2005, August). Evaluación de alcaloides radiculares fluorescentes de la oca (Oxalis tuberosa Mol) y su posible acción en el gorgojo de la oca (Aristidius tuberculatus Voss) (Evaluation of hollow fluorescent root alkaloids (Oxalis tuberosa Mol) and their possible action on the hollow gorilla (Aristidius tuberculatus Voss). Paper presented at the III Congreso Internacional de Cientificos Peruanos, Universidad Nacional Agraria La Molina, Lima, Peru.
  13. Samorini, G. (2015). Acerca de la presencia de beta-carbolinas en tejidos biológicos de los hallazgos arqueológicos sudamericanos (About the presence of beta-carbolines in biological fabrics of South American archaeological hallazgos) Retrieved from https://www.samorini.it/doc1/sam/samorini-acerca-de-la-presencia-de-beta-carbolinas-en-tejidos-biologicos-de-los-hallazgos-arqueologicos-sudamericanos.pdf
  14. Ovalle, M., & Ricardo, I. (2008). Formaciones aldeanas tempranas en el Desierto de Atacama: Nuevos indicadores bioculturales para el Valle de Azapa (Early African formations in the Atacama Desert: New biocultural indicators for the Azapa Valley)  22 Reunión Anual de Etnología, 45–73.
  15. Pfau, W., & Skog, K. (2004). Exposure to beta–carbolines norharman and harman. J.Chromat.B, 802(1), 115–126.
  16. Papavergou, E., & Herraiz, T. (2003). Identification and occurrence of 1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid: The main beta-carboline in smoked foods. Food Res.Intern., 36(8), 843–848. Retrieved from https://www.researchgate.net/publication/222193381_Identification_and_occurrence_of_1234-tetrahydro-b-carboline-3-carboxylic_acid_The_main_b-carboline_alkaloid_in_smoked_foods
  17. Poindexter, E. H., & Carpenter, R. D. (1962). The isolation of harmane and norharmane from tobacco and cigarette smoke, Phytochem., 1(3), 215–221
  18. Agüí, L., Peña-Farfal, C., Yáñez-Sedeño, P., & Pingarrón, J. M. (2007). Determination of beta-carboline alkaloids in foods and beverages by high-performance liquid chromatography with electrochemical detection at a glassy carbon electrode modified with carbon nanotubes. Anal.Chim.Acta, 585(2), 323–330.
  19. Jennings, J. (2005). La chichera y el patrón: Chicha and the energetics of feasting in the prehistoric Andes. Arch.Pap.Am.Anthrop.Ass., 14, 241–259.
  20. Guan, Y., Luis, E. D., & Zheng, W. (2001). Toxicokinetics of tremorgenic natural products, harmane and harmine, in male Sprague-Dawley rats.  J.Toxicol.Environm.Health A, 64(8).: 645–660.
  21. Zhao T., Zheng, S. S., Zhang, B. F., Li, Y. Y., Bligh, S. W., Wang, C. H., & Wang, Z. T. (2012). Metabolic pathways of the psychotropic-carboline alkaloids, harmaline and harmine, by liquid chromatography/mass spectrometry and NMR spectroscopy, Food Chem., 134(2) 1096–1105.
  22. Miller J. M., Albarracin-Jordan, J., Moore, C, & Capriles, J. M. (2019). Chemical evidence for the use of multiple psychotropic plants in a 1,000-year-old ritual bundle from South America, PNAS 116(23),11207–11212.
  23. Samorini, G. (2017). Las fechas más antiguas de la relación humana con las drogas (The most ancient closures of the human relationship with drugs) Revista Cultura y Droga, 21, 91–113.
  24. Samorini, G. (2019) The oldest archeological data evidencing the relationship of Homo sapiens with psychoactive plants: A worldwide overview. Journal of Psychedelic Studies, 3(2), 1–18.
  25. Samorini G. (2014). Aspectos y problemas de la arqueología de las drogas sudamericanas (Aspects and problems of the archeology of South American drugs) Revista Cultura y Droga, 19(21), 13–34.

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