Why Is Citric Acid Used as an Antioxidant?

Citric acid contains a significant amount of vitamin C--a potent antioxidant also known as ascorbic acid--which protects against free radicals and produces collagen to maintain blood vessel structure and heal wounds.

Facts

• Antioxidants protect against, and in some cases reverse, oxygen damage. Citric acid slows oxidation, like when lemon juice prevents a cut apple from turning brown.

Sources

• Antioxidants from citric acid can come from limes, lemons, oranges and other citrus fruits. The American Dietetic Association says a diet rich in whole grains, vegetables and nuts provides all the antioxidants you need.

Considerations

• Citric acid, a rich source of vitamin C, can contribute to a healthy immune system. However, controversy exists over the potential toxicity of vitamin C, as extremely high doses can cause kidney problems.

History

• Citric acid's role as a powerful nutrient-dense food and antioxidant goes back several centuries to when British sailors discovered limes prevented them from developing scurvy on long voyages.

Significance

• Fruit juices, including those that contain citric acid, play an important role in delaying the onset of Alzheimer's disease, according to a study of elderly people in Seattle, published in "The American Journal of Medicine" in 2006.