Guayusa (Ilex guayusa): Benefits, Dosage, Safety & Evidence

Questions fréquentes

How does guayusa provide sustained energy without the jitters?

Guayusa contains a unique balance of stimulants, specifically caffeine and L-theanine. While caffeine stimulates the central nervous system to promote alertness, L-theanine promotes relaxation without drowsiness. This combination is believed to provide a smoother, more sustained energy release compared to coffee, preventing the sudden 'crash' or jitters often associated with isolated caffeine consumption. (Evidence Level: C/Traditional)

Does guayusa interact with stimulants or blood thinners?

Due to its caffeine content, guayusa may interact with stimulant drugs, potentially increasing heart rate and blood pressure. It may also interact with blood thinners like warfarin, as caffeine can affect clotting factors, though specific studies on guayusa are limited. Patients taking MAOIs or medications for heart arrhythmias should avoid guayusa. Always consult a physician before combining with prescription medications. (Evidence Level: C)

What is the recommended dosage for guayusa tea?

The traditional adult dosage for guayusa is 2 to 4 grams of dried leaves brewed as a tea, taken one to three times daily. This amount typically provides a moderate dose of caffeine suitable for sustained energy. Beginners should start with a lower amount (1-2 grams) to assess tolerance, especially if sensitive to stimulants. (Evidence Level: Traditional)

Is guayusa safe to consume during pregnancy?

Guayusa is considered unsafe during pregnancy and breastfeeding due to its caffeine content. High caffeine intake has been linked to miscarriage, low birth weight, and other developmental risks. Health authorities generally recommend limiting caffeine intake during pregnancy; however, because guayusa's specific safety profile lacks robust clinical trials, it is best avoided entirely while pregnant or nursing. (Evidence Level: D)

Can guayusa really help with lucid dreaming?

Traditionally, the Kichwa people of the Amazon have used guayusa to induce lucid dreams and improve dream recall. While scientific evidence is limited (Level C), the theory suggests that the combination of caffeine and L-theanine may maintain a state of mental awareness during REM sleep. Users typically consume the tea in the early morning hours to facilitate this state of consciousness. (Evidence Level: Traditional)

Fiche d'information compilée à partir de PubMed

Cette fiche a été compilée à partir de résumés PubMed (NIH) avec l'assistance d'une IA. Chaque affirmation factuelle est citée par un article PubMed réel (voir la liste des sources). Elle n'a pas encore été révisée par un humain — confirmez auprès d'un professionnel de santé avant utilisation.

Compilé à partir de 30 articles PubMed · modèle : gemma4:31b

Résumé

Guayusa (Ilex guayusa) is an Amazonian evergreen tree used traditionally as a stimulant and antioxidant beverage [PMID:31366209, PMID:28188617].

Contexte

Ilex guayusa is an evergreen tree native to South America, specifically the upper Amazon region of Ecuador [PMID:28188617, PMID:31366209].

Usages traditionnels

It has been consumed for centuries by Amazonian indigenous tribes, such as the Kichwa and Achuar (Jivaro) Indians, as a morning stimulant and in ceremonial contexts [PMID:31366209, PMID:1682531, PMID:42228731].

Composés actifs

The plant contains methylxanthines (caffeine and theobromine), chlorogenic acids, flavonoids, and sugars [PMID:26811391]. It is also rich in pentacyclic triterpenoids (including ursolic acid and amyrin esters), carotenoids (primarily lutein), and various phenolic compounds [PMID:30599971, PMID:28188617, PMID:34467704].

Mécanisme d'action

Ursolic acid found in guayusa extracts is identified as an activator of TGR5, a nuclear receptor involved in the regulation of insulin sensitivity and energy expenditure [PMID:30599971].

Preuves cliniques

Preuve BCognitive Performance

A single dose of 650 mg guayusa extract significantly improved reaction time during N-Back tasks and the number of correct responses and attempts during Serial 7s tasks, though it reduced correct responses in No-go stimulus response [PMID:38140277].

Preuve BMood and Cognition

A 600 mg dose of guayusa leaf extract significantly improved total mood disturbance [PMID:39014963].

Preuve DDiabetes (Animal Model)

In female streptozotocin-induced diabetic rats, guayusa tea administration improved glycaemia and autonomic modulation [PMID:40143095].

Preuve DDental Remineralization (In Vitro)

Ilex guayusa extracts exhibited phosphate and orthophosphate mineral apposition on teeth with Amelogenesis imperfecta [PMID:34498426].

Synthèse des preuves

Evidence consists primarily of phytochemical analyses, in vitro studies, and animal models (Level D), with a limited number of small-scale randomized controlled trials (Level B) assessing acute cognitive and mood effects.

Sources PubMed

1.PMID: 38140277 (2023) — Acute Effects of Naturally Occurring Guayusa Tea and Nordic Lion's Mane Extracts on Cognitive Performance. · Nutrients
2.PMID: 31366209 (2020) — A critical review of the composition and history of safe use of guayusa: a stimulant and antioxidant novel food. · Critical reviews in food science and nutrition
3.PMID: 26811391 (2016) — General and Genetic Toxicology of Guayusa Concentrate (Ilex guayusa). · International journal of toxicology
4.PMID: 34467704 (2021) — [Triterpenoids from leaves of Ilex guayusa]. · Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica
5.PMID: 1682531 (1991) — Ritualistic use of the holly Ilex guayusa by Amazonian Jívaro Indians. · Journal of ethnopharmacology

Guayusa

Sources et citations

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