1 3 Eur J Nutr DOI 10.1007/s00394-016-1205-1 ORIGINAL CONTRIBUTION Frying oils with high natural or added antioxidants content, which protect against postprandial oxidative stress, also protect against DNA oxidation damage Oriol A. Rangel-Zuñiga 1,2 · Carmen Haro 1,2 · Carmen Tormos 2,3 · Pablo Perez-Martinez 1,2 · Javier Delgado-Lista 1,2 · Carmen Marin 1,2 · Gracia M. Quintana-Navarro 1,2 · Concha Cerdá 2,3 · Guillermo T. Sáez 2,4 · Fernando Lopez-Segura 1,2 · Jose Lopez-Miranda 1,2 · Francisco Perez-Jimenez 1,2 · Antonio Camargo 1,2 Received: 17 September 2015 / Accepted: 12 March 2016 © Springer-Verlag Berlin Heidelberg 2016 XPC after the intake of the breakfast prepared with SFO, whereas no significant changes at the postprandial state were observed after the intake of the other breakfasts (all p values <0.05). We observed lower 8-OHdG postprandial levels after the intake of the breakfast prepared with VOO and SOP than after the intake of the breakfast prepared with SFO and SOX (all p values <0.05). Conclusions Our results support the beneficial effect on DNA oxidation damage of virgin olive oil and the oil mod- els with added antioxidants, as compared to the detrimental use of sunflower oil, which induces p53-dependent DNA repair pathway activation. Keywords Frying oils · Virgin olive oil · Oxidative stress · DNA oxidation damage · Phenolic compounds Introduction Eating out is becoming a common habit nowadays, espe- cially for people from developed countries, mainly due to busy work schedules and social factors, and these meals usually contain fried food [1, 2]. During the frying pro- cess, the oils undergo repeated heating cycles at high tem- peratures, which affects their safety for consumption, since the toxic oxidative compounds generated by heating may be absorbed into the foods and ingested [1, 3]. Few stud- ies have focused on the biological consequences of frying oil consumption in humans. However, it has been shown that the content of polar compounds in frying oils has been associated with endothelial dysfunction and hypertension [4, 5], and that frying oils rich in phenolic compounds of olive origin, whether natural or added to a mixed seed oil, after heating at frying temperature, reduce the postprandial inflammatory response as compared to sunflower oil intake Abstract Purpose Using sunflower oil as frying oil increases post- prandial oxidative stress, which is considered the main endogenous source of DNA oxidative damage. We aimed to test whether the protective effect of virgin olive oil and oil models with added antioxidants against postprandial oxida- tive stress may also protect against DNA oxidative damage. Methods Twenty obese people received four breakfasts following a randomized crossover design consisting of dif- ferent oils [virgin olive oil (VOO), sunflower oil (SFO), and a mixed seed oil (SFO/canola oil) with added dimeth- ylpolysiloxane (SOX) or natural antioxidants from olives (SOP)], which were subjected to 20 heating cycles. Results We observed the postprandial increase in the mRNA levels of p53, OGG1, POLB, and GADD45b after the intake of the breakfast prepared with SFO and SOX, and an increase in the expression of MDM2, APEX1, and Francisco Perez-Jimenez and Antonio Camargo have contributed equally in this work. * Antonio Camargo b92cagaa@uco.es; antonio.camargo@imibic.org 1 Lipids and Atherosclerosis Unit, IMIBIC/Reina Sofia University Hospital/University of Córdoba, Av. Menendez Pidal s/n., 14004 Córdoba, Spain 2 CIBER Fisiopatología de la obesidad y la nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain 3 Department of Biochemistry and Molecular Biology, Service of Clinical Analysis, General University Hospital-CDB, University of Valencia, Valencia, Spain 4 Department of Biochemistry and Molecular Biology, Service of Clinical Analysis, School of Medicine-INCLIVA, University Hospital Doctor PESET, University of Valencia, Valencia, Spain