In addition to avoiding pesticides and other chemicals, people who choose organic fruits and vegetables now have yet another reason to buy organic.

A new study at University of California, Davis, shows that organically grown tomatoes have much higher levels of flavonoids than tomatoes grown “conventionally”.

Commonly known for their antioxidant benefits, previous evidence has shown that flavonoids may fight age-related diseases, such as cardiovascular diseases and certain types of cancer, and scientists have been in search of crops with higher levels of these antioxidants.

Writing in the Journal of Agriculture and Food Chemistry, researchers said the level of flavonoids in the organic tomatoes was almost twice as high as that in industrially grown tomatoes.

Studying these crops grown over a 10-year period in organic and non-organic fields, it was not only found that organic tomatoes scored better, but over time, their flavonoid levels kept increasing!

The chief author of the study. Dr. Alyson Mitchell, said she was surprised at the difference. “We went into this expecting higher levels, but we did not expect to find the levels that we found.”

The study offered several possible explanations, most having to do with the fertility of the soil. The researchers write that organic farms gradually improve the soil by letting organic matter accumulate though the use of cover crops, compost and manure.

It has recently been found in another study that the use of organic fertilizers and “green manure” increases the soil quality over time, thereby increasing the quality and nutritional content of the crop it yields.