Organically grown food has been found to have higher levels of antioxidants than non-organic food. This conclusion is not based on the result of one study or even one hundred studies; this was the finding of a metastudy that analyzed the results of 343 peer-reviewed publications!
In 2014, a study published by Cambridge University Press found “statistically significant and meaningful differences in composition between organic and non-organic crops/crop-based foods. Most importantly, the concentrations of a range of antioxidants such as polyphenolics were found to be substantially higher in organic crops/crop-based foods…
Many of these compounds have previously been linked to a reduced risk of chronic diseases, including CVD [cardiovascular disease] and neurodegenerative diseases and certain cancers, in dietary intervention and epidemiological studies.”
The researchers suggest that simply switching your diet from non-organic to organic food can result in 20-40% (and up to 60% for certain compounds) increase in levels of antioxidants and (poly)phenols consumed. To put this in simpler terms, for every five servings of fruits and vegetables you consume (the British recommendation for daily intake), you may get the extra goodness (in terms of these compounds) of one to two servings if you choose organic.
Why does organic food contain higher levels of antioxidants?
Plants that receive their nutrients from green manures, compost and other organic soil amendments have higher levels of these antioxidants and polyphenols than plants grown with mineral fertilizers, according to various studies. The authors of the 2014 study suggest that when nitrogen levels are at the levels commonly found on farms that rely on synthetic fertilizers, plants focus their energy into rapid growth and primary metabolism. In contrast, when nitrogen is less readily available, such as on farms that use compost and green manures as the basis of fertility, the plants grow a bit more slowly but produce higher levels of antioxidants and polyphenols.
For humans who consume the plants, the antioxidants and related substances keep our bodies healthy from various diseases. In plants, the compounds that form antioxidants are used as a defense against pests and injuries. Insects are less likely to attack plants with high levels of these compounds. So it’s a win-win for organics! Consumers get healthier food and organic farmers get more robust plants.
The study also found lower levels of cadmium, a toxic heavy metal, in organic food. High cadmium levels has been linked to the use of synthetic phosphorus fertilizer.