The Hoasca Project: Proposal For A Biomedical Investigation of Ayahuasca

Summer 1992 Vol. 03, No. 3 Building on Common Ground

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"Ayahuasca" is a Quechua term meaning "vine of the souls," and is one of the numerous indigenous names for the hallucinogenic drink prepared from a combination of two Amazonian plants, Banisteriopsis caapi, and Psychotria viridis. In Amazonian Peru and parts of Colombia and Ecuador, the drink is known as ayahuasca; in other parts of the Amazon, it is known as yage, natema, or pilde; in Brasil, it is known as hoasca, or sometimes simply "the tea." In whatever cultural context it is found, and by whatever name, ayahuasca plays a pivotal role both in the spiritual life of the populations that use it, and in local ethnomedical practices. The drink is regarded as both a sacrament, and a medidne. For the shamans familiar with its properties, it is both a diagnostic aid and a respected teacher, for the patients who seek the healing the shamans can offer, it is the ideal holistic medicine, providing the means to cleanse and heal both the mind and the body. From the perspective of modern psychopharmacology, practically nothing is known of how it actually effects the human mind / body.

Recently, a unique opportunity has become available to carry out a biomedical investigation of the immediate and long-term effects of ayahuasca in human users. This opportunity has resulted from recent friendships established by the author, Dennis McKenna, with members of a Brasilian organization, the União do Vegetal (UDV) which is essentially a syncretic religious movement in which the collective, periodic ingestion of hoasca tea is the central ceremony and sacrament. Unlike the more traditional use of ayahuasca in the context of mestizo or aboriginal shamanism, the use of hoasca tea within the UDV is strictly regarded as a religious or spiritual practice (as opposed to a curing or medical practice). Moreover, many of the younger adherents to the UDV "cult" tend to be well-educated, urban professionals. Some of the members are Western-trained physicians, psychiatrists, or other health profession- als, who frequently possess a solid training in medical disciplines and a healthy sdentific curiousity about the physical and psychological effects of hoasca tea. They understand as much as anyone does about the active alkaloids found in hoasca tea, and about its putative mechanism of action. They would like to learn all that can be learned about how it works, but at the same time they maintain a sense of reverence regarding their sacrament; they consider that an effort to understand hoasca using the tools and paradigms of science is not a sacrilege, if it is pursued as part of a sincere effort to increase our knowledge of this remarkable medicine.

This enlightened attitude establishes an intellectual climate in which a pharmacological and psychological investigation of hoasca could be carried out, if the required resources were available. While attending a conference on the biomedical aspects of hoasca which was hosted by the UDV in Sao Paulo in June, 1991, I made a proposal for a biomedical investigation of the human pharmacology of hoasca to some of the leaders of the UDV. The response was more than receptive; it was enthusiastic Since this conference, we have remained in frequent contact, and have continued to work together on developing a proposal setting forth the objectives and methodologies for a pilot study on the action of hoasca in humans.

As currently conceived, a number of parameters related to the psychophysiological effects of hoasca will be investigated, among them the following:

  • Composition of hoasca teas. The UDV recognizes several kinds of hoasca, which differ in their modes of preparation and in their effects. The composition and amount of active alkaloids in these various types of tea will be analyzed and compared.
  • Acute pharmacokinetics of hoasca. Pharmacokinetics is the study of the absorbtion, metabolism, and excretion of drugs. The pham~cokinetics of the major alkaloids of hoasca (harmine and DMT) will be determined in blood samples taken from volunteers using a technique known as gas chromatography/mass spectrometry (GC/MS).
  • Acute / long-term effects of hoasca on serotonergic functions. Hoasca, like other hallucinogens, is known to interact primarily with receptors for the neurotransmitter serotonin (5-HT, 5-hydroxytryptamine).

The effects of hoasca on serotonergic functions can be determined in blood and plasma samples by analyzing various parameters, such as levels of hormones known to be modulated by the serotonin system (e.g., prolactin, ACTH, B-endorphin). In addition, blood platelets contain many of the same serotonin receptors that are found in the brain, and psychopharmacologists have long used platelet receptor binding assays as a peripheral marker for changes presumably occurring in the central nervous system. We propose to use platelets to moniter the effects of hoasca on certain serotonin receptor subtypes, and also to measure peripheral monoamine oxidase (MAO) inhibitiors These parameters will be measured in volunteers, drown from the membersof the UDV, before and after the ingestion of known doses of hoasca tea.

In addition, a parallel study will investigate the possible long-term effects of hoasca by examining these parameters in a group of older maestres, members of the UDV who have taken hoasca regularly for much of their adult lives. This group of maestres will be compared with a set of age-matched control volunteers who have not taken hoasca.

These are the primary objectives of the initial study. Additional parameters may also be measured, such as the effect of hoasca on immune functions, or its effect on cognitive function as measured by psychological and cognitive assessment procedures.

Good science cannot be done for free, or even cheaply. The complete study outlined in our proposal would require about 6 months and $50,000 to complete. We are in the process of preparing a formal grant proposal for submission to NIDA (National Institute on Drug Abuse) in September of this year. The Prindple Investigator for the study will be Dr. Charles S. Grob, a psychiatrist and faculty member in the Department of Psychiatry and Human Behavior, U.C. Irvine (Dr. Grob is also the lind investigator in the MDMA research project). Although we will submit the proposal to NIDA, we feel that the prospect of receiving funding for the project from this source is rather slim. In this era of a shrinking government research budget, NIDA is unlikely to fund a grant on a little-known South American hallucinogen that not only is not a major drug-abuse problem, but may actually bring some benefit to those who use it.

The political realities of government-supported Big Science being what they are, this is not the kind of thinking NIDA wants to hear, much less fund, An alternative possibility is to seek funding from non-government sources, either private foundations or interested individuals. One such donor, whose life has been touched in a very personal way by hoasca, has pledged a donation of $10,000 to support the study. This donation will be placed into a special account, to be administered by Botanical Dimensions and held apart from general operating funds. We are hoping that this will encourage other individuals, who have finandal resources and would like to see progress in this field of research, to contribute to the support of this study. We hasten to remind you: Botanical Dimensions operates on a shoestring and depends on your contributions for its support. We still need those contributions, in order to continue the work that we are doing to investigate and protect ethnomedical plants and lore. But the hoasca study is also within this spirit and certainly fits within our mandate as an ethnomedical research organization. It is also an opportunity to support the investigation of one of the most significant, but least understood, of the New World hallucinogens. Individuals who are interested in contributing to the fund for the hoasca study and would like more details on the planned research should contact Dennis McKenna, through MAPS or Botanical Dimensions.

Botanical Dimensions
P.O. Box 807
Occidental, CA, 95465
(707) 874-1531