Organic foods and crops offer more health benefits than their traditional counterparts, according to a Washington State University study. Researchers said that organic fruits and vegetables comprise more antioxidants and fewer, less frequent pesticide residues.

For the study, the researchers analysed 343 peer-reviewed publications particularly in North and South America and compared the nutritional quality and safety of organic and conventional plant-based foods including fruits, vegetables and grains. Most of the publications examined crops grown on similar soils - eliminating questions surrounding variation in nutritional and safety parameters.

The researchers found that crops grown on conventional fields has higher concentrations of synthetic nitrogen and will divert the extra resources into producing sugars and starches. As a result, the harvested portion of the plant will contain lower amounts of other nutrients including health-promoting antioxidants.

On the other hand, organic crops without the synthetic chemical pesticides generate more phenols and polyphenols to combat pest attacks and related injuries. Overall, organic crops had 18 to 69 percent higher levels of antioxidant compounds.

Researchers said that organic fruit, vegetables, and cereals increase the production of antioxidants by 20 to 40 percent - equivalent to two extra portions of fruit and vegetables a day without increase in caloric intake.

The researchers also found that pesticide residues were three to four times more likely to be present in conventional foods than organic ones. While organic crops do contain pesticide residues, the levels are 10 to 100 times lower when compared to the conventionally grown food.

"This study is telling a powerful story of how organic plant-based foods are nutritionally superior and deliver bona fide health benefits," said Charles Benbrook, a Washington State University researcher and co-author of the paper, in a press release.

The study is published in the British Journal of Nutrition.