British Journal of Nutrition

Research Article

Daily consumption of a high-phenol extra-virgin olive oil reduces oxidative DNA damage in postmenopausal women

Simonetta Salvinia1 c1, Francesco Seraa1, Donatella Carusoa2, Lisa Giovannellia3, Francesco Visiolia2, Calogero Saievaa1, Giovanna Masalaa1, Marco Cerotia1, Valentina Giovacchinia1, Vanessa Pitozzia3, Claudio Gallia2, Annalisa Romania4, Nadia Mulinaccia4, Renzo Bortolomeazzia5, Piero Dolaraa2 and Domenico Pallia1

a1 Molecular and Nutritional Epidemiology Unit, Centro per lo Studio e la Prevenzione Oncologica (CSPO), Scientific Institute of Tuscany, Florence, Italy

a2 Department of Pharmacological Sciences, University of Milan, Milan, Italy

a3 Department of Preclinical and Clinical Pharmacology, University of Florence, Florence, Italy

a4 Department of Pharmaceutical Sciences, University of Florence, Florence, Italy

a5 Department of Food Science, University of Udine, Udine, Italy

Abstract

Extra-virgin olive oils (EVOO), high in phenolic compounds with antioxidant properties, could be partly responsible for the lower mortality and incidence of cancer and CVD in the Mediterranean region. The present study aims to measure oxidative DNA damage in healthy human subjects consuming olive oils with different concentrations of natural phenols. A randomised cross-over trial of high-phenol EVOO (high-EVOO; 592mg total phenols/kg) V low-phenol EVOO (low-EVOO; 147mg/kg) was conducted in ten postmenopausal women in Florence. Subjects were asked to substitute all types of fat and oils habitually consumed with the study oil (50g/d) for 8 weeks in each period. Oxidative DNA damage was measured by the comet assay in peripheral blood lymphocytes, collected at each visit during the study period. Urine samples over 24h were collected to measure the excretion of the olive oil phenols. The average of the four measurements of oxidative DNA damage during treatment with high-EVOO was 30% lower than the average during the low-EVOO treatment (p=0·02). Urinary excretion of hydroxytyrosol and its metabolite homovanillyl alcohol were significantly increased in subjects consuming high-EVOO. Despite the small sample size, the present study showed a reduction of DNA damage by consumption of an EVOO rich in phenols, particularly hydroxytyrosol.

(Received June 06 2005)

(Revised November 03 2005)

(Accepted November 22 2005)

Correspondence:

c1 *Corresponding author: Dr Simonetta Salvini, fax +39 055 32697829, email s.salvini@cspo.it

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