Tannic Acid influence on lead and cadmium accumulation in the hearts and lungs of rats.

BACKGROUND The presence of heavy metals in food products has become a global problem. In order to reduce the absorption of heavy metals from food we should consider substances which bind these toxic metals and are generally available and easy to apply, such as tannins. OBJECTIVES The study aimed at verifying if oral administration of tannic acid could reduce the accumulation of lead and cadmium in the heart and lungs of rats subjected to a continuous exposure of toxic metals in low doses. MATERIAL AND METHODS Adolescent and adult male Wistar rats were given tannic acid (2% solution) or distilled water containing 0, 50, 100 mg Pb (as (CH₃COO)₂Pb)/L or 0, 7, 14 mg Cd (as CdCl₂)/L, for 6 or 12 weeks. RESULTS Administering a 2% solution of tannic acid alternately with Pb or Cd to the rats was the effective method of reducing lead and cadmium content in the rats' heart and lungs. CONCLUSIONS The obtained results may be referred to people. It is necessary to conduct further research in order to confirm the hypothesis that tannic acid, present in numerous food products and primarily in drinks (wine, tea and coffee), used in the human diet, may reduce the accumulation of lead and cadmium in the tissues and thus weaken their toxicity, which is important regarding our common exposure to heavy metals found in food.