In this paper we compare the effects of a polyphenol-rich extract from black chokeberry fruit, chicory flour containing non-digestible fructans and their dietary combination on blood parameters and antioxidant status of healthy and diabetic rats. The rat model of diabetes was induced by streptozotocin (STZ) and characterised by severe hyperglycaemia, hypercholesterolaemia, hypertriglyceridaemia and some disturbances in the antioxidant status, connected with body weight gain (BWG) depression, as well as liver and kidneys enlargement. The dietary treatments had no influence on glycaemia and BWG of the diabetic animals, but significantly alleviated liver and kidneys hypertrophy. The chicory preparation to a lesser extent, but the chokeberry extract – alone or in combination – effectively reduced total cholesterol level in the serum of diabetic rats. Moreover, the dietary combination of both examined preparations diminished triglycerides concentration to the control level observed in healthy animals. The STZ administration substantially decreased integral antioxidant capacity of hydrophilic substances in plasma (ACW), as well as increased the concentration of a lipid peroxidation indicator (TBARS) in the kidney tissue. Both tested dietary additives did not increase ACW, while the extract decreased TBARS concentration in the diabetic rats. Although the preparations used in our experiment did not fully protect against serious diabetic dysfunctions, positive changes observed in the blood parameters (total cholesterol and triglycerides level), as well as attenuated kidneys’ hypertrophy and lipid peroxidation, indicate that the chokeberry fruit extract and/or its combination with chicory flour constituents may provide a useful supplementary therapeutic option in the prevention and treatment of diabetes and its complications.