Toxic metals and antioxidants: Part II. The role of antioxidants in arsenic and cadmium toxicity

Altern Med Rev. 2003 May;8(2):106-28.

Abstract

Exposure to toxic metals has become an increasingly recognized source of illness worldwide. Both cadmium and arsenic are ubiquitous in the environment, and exposure through food and water as well as occupational sources can contribute to a well-defined spectrum of disease. The symptom picture of arsenic toxicity is characterized by dermal lesions, anemia, and an increased risk for cardiovascular disease, diabetes, and liver damage. Cadmium has a significant effect on renal function, and as a result alters bone metabolism, leading to osteoporosis and osteomalacia. Cadmium-induced genotoxicity also increases risk for several cancers. The mechanisms of arsenic- and cadmium-induced damage include the production of free radicals that alter mitochondrial activity and genetic information. The metabolism and excretion of these heavy metals depend on the presence of antioxidants and thiols that aid arsenic methylation and both arsenic and cadmium metallothionein-binding. S-adenosylmethionine, lipoic acid, glutathione, selenium, zinc, N-acetylcysteine (NAC), methionine, cysteine, alpha-tocopherol, and ascorbic acid have specific roles in the mitigation of heavy metal toxicity. Several antioxidants including NAC, zinc, methionine, and cysteine, when used in conjunction with standard chelating agents, can improve the mobilization and excretion of arsenic and cadmium.

Publication types

  • Review

MeSH terms

  • Antioxidants / therapeutic use*
  • Arsenic / metabolism
  • Arsenic Poisoning / complications
  • Arsenic Poisoning / drug therapy*
  • Cadmium / metabolism
  • Cadmium Poisoning / complications
  • Cadmium Poisoning / drug therapy*
  • Chelating Agents / therapeutic use*
  • Heavy Metal Poisoning
  • Humans
  • Metals, Heavy / metabolism
  • Methylation
  • Risk Factors

Substances

  • Antioxidants
  • Chelating Agents
  • Metals, Heavy
  • Cadmium
  • Arsenic