Prepared Foods October 31, 2005 e-newsletter

Virgin olive oil phenols may exert anticancer effects on colorectal carcinogenesis.

"The traditional Mediterranean diet is thought to represent a healthy lifestyle, especially given the incidence of several cancers including colorectal cancer is lower in Mediterranean countries compared to Northern Europe. Olive oil, a central component of the Mediterranean diet, is believed to beneficially affect numerous biological processes," scientists in North Ireland reported.

"We used phenols extracted from virgin olive oil on a series of in vitro systems that model important stages of colon carcinogenesis. The effect the extract on DNA damage induced by hydrogen peroxide was measured in HT29 cells using single-cell microgel-electrophoresis," described C.I.R. Gill and colleagues, University of Ulster.

"A significant anti-genotoxic linear trend (p=.011) was observed when HT29 cells were preincubated with olive oil phenols (0, 5, 10, 25, 50, 75, 100mcg/ml) for 24 hours, then challenged with hydrogen peroxide. The olive oil phenols (50, 100mcg/ml) significantly (p=.004, p=.002) improved barrier function of CACO cells after 48 hours as measured by transepithelial resistance."

"Significant inhibition of HT115 invasion (p<.01) was observed at olive oil phenols concentrations of 25, 50, 75, 100mcg/ml using the matrigel invasion assay. No effect was observed on HT115 viability over the concentration range 0, 25, 50 75, 100mcg/ml after 24 hours, although 75 and 100mcg/ml olive oil phenols significantly inhibited HT115 cell attachment (p=.011, p=.006). Olive oil phenols had no significant effect on metastasis-related gene expression in HT115 cells."

The researchers concluded, "We have demonstrated that phenols extracted from virgin olive oil are capable of inhibiting several stages in colon carcinogenesis in vitro."

Gill and colleagues published their study in International Journal of Cancer (“Potential Anti-cancer Effects of Virgin Olive Oil Phenols on Colorectal Carcinogenesis Models in Vitro.” Int J Cancer, 2005;117(1):1-7).

For more information, contact C.I.R. Gill, University of Ulster, No Ireland Center Food & Health, Cromore Rd., Coleraine BT52 1SA, Londonderry, North Ireland.