1. ¹Unitat de Recerca en Farmacologia, Institut Municipal d'Investigació Mèdica, Barcelona, Spain
2. ²Unitat de Lipids I Epidemiologia Cardiovascular, Institut Municipal d'Investigació Mèdica, Barcelona, Spain

Correspondence: M I Covas, Unitat de Lipids I Epidemiologia Cardiovascular, Institut Municipal d'Investigació Mèdica, Carrer Dr Aiguader 80, 08003 Barcelona, Spain. E-mail: mcovas@imim.es

^*Guarantor: MI Covas.

Received 22 March 2002; Revised 3 May 2002; Accepted 17 May 2002.

Abstract

Objective: To investigate the absorption of tyrosol and hydroxytyrosol from moderate and sustained doses of virgin olive oil consumption. The study also aimed to investigate whether these phenolic compounds could be used as biomarkers of virgin olive oil intake.

Design and interventions: Ingestion of a single dose of virgin olive oil (50 ml). Thereafter, for a week, participants followed their usual diet which included 25 ml/day of the same virgin olive oil as the source of raw fat.

Setting: Unitat de Recerca en Farmacologia. Institut Municipal d'Investigació Mèdica (IMIM).

Subjects: Seven healthy volunteers.

Results: An increase in 24 h urine of tyrosol and hydroxytyrosol, after both a single-dose ingestion (50 ml) and short-term consumption (one week, 25 ml/day) of virgin olive oil (P<0.05) was observed. Urinary recoveries for tyrosol were similar after a single dose and after sustained doses of virgin olive oil. Mean recovery values for hydroxytyrosol after sustained doses were 1.5-fold those obtained after a single 50 ml dose.

Conclusion: Tyrosol and hydroxytyrosol are absorbed from realistic doses of virgin olive oil. With regard to the dose–effect relationship, 24 h urinary tyrosol seems to be a better biomarker of sustained and moderate doses of virgin olive oil consumption than hydroxytyrosol.

Sponsorship: This work was supported by grants ALI97-1607-CO2-01 from CICYT, 98/9562 FPI from FIS and by Federació de Cooperatives Agràries de Catalunya.