And the answer is…probably not.
The “first published systematic review investigating differences in nutrient content of organically and conventionally produced foodstuffs” was recently published. This has been a hot and controversial topic for a long time, so I’m glad someone finally did a good, thorough review.
They did a review – not a lab study – but a review of the existing literature to see what the entire mass of published literature on the topic has to say. So instead of saying, “this study says this” and “this study says that,” they looked at what the whole body of research says when combined.
In an analysis that included only satisfactory-quality studies, conventionally produced crops had a significantly higher content of nitrogen, and 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 satisfactory quality crop studies found no evidence of a difference in 8 of the 11 nutrient categories (vitamin C, phenolic compounds, magnesium, potassium, calcium, zinc, copper, and total soluble solids) (Table 1). Nitrogen contents were significantly higher in conventionally produced crops, and contents of phosphorus and titratable acidity were significantly higher in organically produced crops.
…Differences that were detected in crops were biologically plausible and were most likely due to differences in fertilizer use (nitrogen and phosphorus) (3) and ripeness at harvest (titratable acidity) (16). It is unlikely that consumption of these nutrients at the concentrations reported in organic foods in this study provide any health benefit.
…The current analysis suggests that a small number of differences in nutrient content exist between organically and conventionally produced foodstuffs and that, whereas these differences in content are biologically plausible, they are unlikely to be of public health relevance. One broad conclusion to draw from this review is that there is no evidence to support the selection of organically produced foodstuffs over conventionally produced foodstuffs to increase the intake of specific nutrients or nutritionally relevant substances.
Now, clarification: I do support organic agriculture practices. I am not dogmatic about it, but I think overall we would probably all be better off if we didn’t have as many pesticides and synthetic fertilizers being sprayed around. However, there is a difference between supporting organic for environmental reasons (pesticides, fertilizers, environmental impact, etc.) and supporting it because you think you’re getting more nutrients from organic food.
The researchers even clarify this themselves:
The outcome was restricted to the nutrient and nutritionally relevant content of foodstuffs. We did not address differences in contaminant contents (eg, herbicide, pesticide, or fungicide residues) or the possible environmental consequences of organic and conventional agricultural practices because this was beyond the scope of our review.
I don’t think there’s much of a question about organics containing less pesticides, etc. than conventional produce. But the point here is that you’re not getting more calcium or magnesium from organic produce than you would from conventional produce.
I don’t think we can necessarily call this “case closed,” because science is always evolving with more recent research. But I think we now have some good research to put behind our informed decisions.