For 4 weeks, male outbred IF₂Jaz rats, divided into 4 groups (n=10), were administered ad libitum diets with 30% addition of dried tubers of transgenic potatoes with repression of isoform a, c as well as a and c of 14-3-3 protein (experimental groups) or with the addition of non-transgenic potatoes of Desiree cultivar (control group). The administration of transgenic potatoes did not affect the growth rate of model animals nor most of the analysed parameters of their health status. Neither anti-nutritional, nor immunostimulatory or toxic effects of the experimental diets were demonstrated. Yet, in liver tissue of rats fed a diet with transgenic potatoes J4 and G1 the concentration of 8-oxo-2’deoxyguanosine – a biomarker of oxidative damage to DNA – was higher than in animals administered a diet with non-transgenic potatoes. Results obtained in the study indicate a threat to the health status of animals fed diets with a high content of genetically-modified potatoes with repression of 14-3-3 protein.