Given the importance of oxidative stress associated to aging, it would be interesting to assess the effect of oral supplementation with antioxidant substances capable of diminishing oxidative aggression and free radicals generation associated to this condition. This study investigated the effects of AIN-93 M diet supplemented either with 2 % of propolis, or with 4 % of a natural product obtained from lyophilizate vegetables, selected by its antioxidant properties, in senescent healthy Wistar rats fed ad libitum over 3 months. Propolis supplementation leads to a lower level of glucose and cholesterol concentrations together with a reduction in protein oxidation. Plasma thiobarbituric acid-reactive substance levels were lower in the rats consuming the natural vegetable product and propolis possibly due to its antioxidant components, neutralizing the free radical produced, and thus preventing cellular damage. The results of the present study suggest a synergic effect of overall propolis compounds reducing the oxidative stress and glucose and cholesterol plasma levels associated with aging.