This is a big question, and there aren't really simple answers to it. Many people choose organic because of what it lacks - pesticides, herbicides, hormones, etc. But some people look to organic because it offers more health benefits.
So the question becomes....does science support what seems intuitive?
I want to highlight one recent study, published in the British Journal of Nutrition in July. The study is actually a review of previous studies - compiling the research to see what the cumulative voice says. Their answer? That organic crops contain more antioxidants, less cadmium (a toxic heavy metal), and less pesticide residue.
Say more about the antioxidants.
The concentration of some antioxidants was higher in the organic produce. Meaning that gram for gram - and calorie for calorie - organic foods have more of these antioxidants and health benefits.
The specific antioxidants found in higher concentrations were polyphenols, flavanoids, resveratrol, and anthocyanins. The differences between these antioxidants isn't super important to nit-pick over, but I think that it's nice to see they have actual names, not just "some antioxidants".
A number of research studies have shown that a diet rich in antioxidants is protective against chronic diseases - including cardiovascular disease, some cancers (e.g. prostate), and neurodegenerative diseases [1, 2].
Now, as I said, this is just one study. There are others that show health benefits to organic foods. But there are others that do not confirm these health benefits. This isn't conclusive, but it IS a large study that pulls evidence from many different places. The problem is that the studies are hard to lump together - the terms organic and conventional can end up looking many different ways in practice.
NPR did a little write-up on the study, and interviewed one of the co-authors. He made a few interesting comments that I thought were worth passing along.
Specifically he addressed why the study might have found an increase in the antioxidant levels. Plants make antioxidants for protection - I liken it to a human's immune system. When the plant doesn't have the help of chemical pesticides, it must build up it's own protective measures. Thus, more antioxidants in organic foods. Another theory is that the fertilizers that make conventional plants grow bigger and faster mean that the vitamins, minerals and antioxidants might get diluted - gram for gram.
If there is ANY evidence that organic foods have more antioxidants (or vitamins, minerals, or other health benefits) - I'm calling it a win. When I see the term organic, I like what it means IS NOT in my food, and now I can also think about what it means is IN my food.
But when push comes to shove, I'm thinking about the benefits of these antioxidants, and finding ways to increase my consumption of fruits and vegetables (and wine, coffee, tea, and chocolate - to a less extent!). Adding more fruits and vegetables is going to increase my antioxidant intake, and provide many of those health benefits I'm looking for.
What do you think? Does the fact that organic foods are more likely to have an increased concentration of antioxidants a factor for you? Does this information change your view on organic foods?
1. Del Rio D, Rodriguez-Mateos A, Spencer JPE, et al. (2013) Dietary (poly)phenolics in human health: structures, bioavailability, and evidence of protective effects against chronic diseases. Antioxid Redox Signal 18, 1818-1892.
2. Wahlqvist ML (2013) Antioxidant relevance to human health. Asia Pac J Clin Nutr 22, 171-176.