Organic tomatoes container higher levels of antioxidants than those grown conventionally, according to a study from Spain.

Antioxidants—phenolic compounds—are found in many fruits and vegetables and have proven benefits for human health. Their consumption has been linked to the prevention of cardiovascular and degenerative diseases and some forms of cancer.

Researchers from the University of Barcelona linked the differences between organic and conventional tomatoes to the types of fertilizer used. “Organic farming doesn’t use nitrogenous fertilizers; as a result, plants respond by activating their own defense mechanisms, increasing the levels of all antioxidants,” said Anna Vallverdu Queralt, PhD

SOURCE

"Organic Tomatoes Contain Higher Levels of Antioxidants than Conventional Tomatoes" University of Barcelona, 7/3/12