It may be in the soil and not the actual agricultural methods! A review published as Nutritional Quality of Organic Foods: a systematic review by Dangour et al has concluded that:

“there is no evidence of a difference in nutrient quality between organically and conventionally produced foodstuffs.  The small differences in nutrient content detected are biologically plausible and mostly relate to differences in production methods.”

This group looked at a total of 52,471 articles, and identified 162 studies (137 crops and 25 livestock products) 55 of which were of satisfactory quality.
Of the 55 studies which were considered satisfactory:
•    Conventionally produced crops had a significantly higher content of nitrogen
•    Organically produced crops had a significantly higher content of phosphorus and higher titratable acidity
•    No evidence of a difference was detected for the remaining 8 of 11 crop nutrient categories analyzed.
•    Analysis of the more limited database on livestock products found no evidence of a difference in nutrient content between organically and conventionally produced livestock products.

This paper has attracted a lot of attention, and there will no doubt be shrieks of outrage from those who believe that organic food provides more vitamins and minerals and is always “better.”

One thing to consider with regards to plant nutrients is that the nutrients are in plants for a reason and if it does not have them, it does not grow- regardless of where it comes from (R. Maughan, 2009). These comments perhaps apply more to the organic nutrients (carbohydrates, proteins or amino acids, lipids, and vitamins) that are made by the plants than they do to minerals and other inorganic components.

For example, there is solid evidence that wheat grown in soil with low selenium content will itself have low selenium content. British soil is generally low in selenium so wheat from the UK has low selenium content, wheat from Canada does not. In any case, some may argue that use of appropriate fertilizers is more likely to be effective in producing crops with appropriate nutrient content than is the use of organic farming methods.

Aside from nutrient content there are still various other factors to consider in regards to organic produce; the long-terms effects of pesticide use, the carbon footprint associated with transport of products from far away, etc… We as consumers face difficult choices every day that involve balancing the risks and benefits of our activities. Some research is showing that buying organic may reduce some risks associated with agriculture and food. As well, one more factor to consider is that your local community plays a role in defining what choices you have available, e.g. if buying local is an option.

Peter Melchett, policy director at the Soil Association said they were disappointed with the conclusions. “The review rejected almost all of the existing studies of comparisons between organic and non-organic nutritional differences”.

He continues “although the researchers say that the differences between organic and non-organic food are not ‘important’, due to the relatively few studies, they report in their analysis that there are higher levels of beneficial nutrients in organic compared to non-organic foods”.

Dana Lis, SportMed Dietitian adds “When I was visiting Iceland, buying local produce was really not an option at all – red peppers were 8 dollars Canadian. Regardless, if you buy local, organic, whatever is on sale or a little bit of everything; one step to a healthier and more sustainable future – get on a bike!”