Iron-citrate complexes and free radicals generation: is citric acid an innocent additive in foods and drinks?

Biometals. 2007 Oct;20(5):793-6. doi: 10.1007/s10534-006-9042-y. Epub 2007 Mar 28.


The generation of free radicals (Fenton chemistry) from various iron citrate complexes has been studied. Spin trapping methods have been used. The results can question concerning the innocence of added citric acid in foods and cold drinks. We concluded that in absence of pathological situation citric acid is probably not dangerous but it may become dangerous in situation of oxidative stress and/or iron overload.

MeSH terms

  • Citric Acid / adverse effects
  • Citric Acid / metabolism*
  • Citrus sinensis / metabolism
  • Food Additives / adverse effects
  • Food Additives / metabolism*
  • Free Radicals / metabolism*
  • Hydroxyl Radical / metabolism
  • Iron / metabolism*
  • Iron Overload / metabolism
  • Oxidative Stress / physiology


  • Food Additives
  • Free Radicals
  • Citric Acid
  • Hydroxyl Radical
  • Iron