Antioxidants reduce the toxic effects of lead

Oct 31 2008

A research study carried out by the Universidad Complutense de Madrid (UCM) proves that administering natural antioxidants can reduce the effects of lead poisoning in animals during the gestation and lactation periods. The study suggests that it could also be effective in humans.

In this study, published in the magazine Food and Chemical Toxicology, the researchers aimed to prove that since the principal toxicity mechanism of lead poisoning is that it creates free radicals that lead to cellular destruction; administrating natural antioxidants could reverse this process and re-establish the organism's lost balance. The results of the study are preliminary but they could be the beginning of a possible therapeutic treatment to cure the disease.

In order to prove their theory, the researchers carried out an experiment using gestating mice that were separated in to four different groups with different additives in their drinking water. The control group was only subjected to purified water, the drinking water for the second group was contaminated with lead, the drinking water for the third group was also contaminated with lead, but the mice were also treated with antioxidants (zinc, vitamins A,C, E and B6) and the fourth group was just treated with the antioxidants and uncontaminated water.

The research stemmed from the belief that the main cause of the toxicity of lead is the oxidative stress, an imbalance between the antioxidants and the free radicals present in an organism, leading to an excess of free radicals and a consequent destruction of tissues. The results have concluded that such alterations, measured by evaluating various biochemical changes in the brain of the baby mice, diminish in subjects subjected to lead and treated with antioxidants, almost reaching the levels of the control group. The symptoms of lead poisoning were also drastically reduced, reinforcing the theory that administering antioxidants could be a very effective therapy.

Lead poisoning also known as "saturnism" for its violent and demented character that is associated with the god Saturn has been identified at least before the fifth century before Christ. The most common symptoms range from anaemia to irritability, with headaches, motor impairment or weight loss in between. The damages are greater the younger the affected subject, since their organs are at the early stages of development, and they are particularly harsh in subjects below 3 years of age. During gestation, lead can penetrate through the placenta easily and accumulate in the tissues of the embryo, including the brain, which can cause permanent damage such as developmental delay, learning difficulties, hearing problems, diminished memory or aggressiveness. In Europe, the disease occurs in humans mainly as an occupational hazard, and in animals, as a direct consequence of eating hunting pellets. Nevertheless, in other countries, the disease is widely present. For example, the Dominican Republic is home to one of the cities most contaminated by this metal, or the United States, where it is estimated that up to 3% of children are chronically exposed to lead.

The study, carried out by the researchers Mª Teresa Antonio García and Elvira Massó González from the Universidad Complutense de Madrid, used low doses of lead of a similar size to what could normally be assimilated through food or by contact with the environment and has concluded that the treatment with antioxidants is effective. Hopefully these results will provide beneficial treatments for humans in the future.