13 February 2017. The answer may appear straightforward. Of course organic food is better. But there are some caveats as well. First, let us look at the research findings. They were recently summarized in a report requested by the European Parliament. In the 88-page review of 381 publications, researchers from four EU countries covered a variety of topics, including potential human health benefits of the organic food as such, and indirect benefits from organic feed and production methods.
Risks associated with pesticide residues are well known, and we shall return to this issue shortly. Organic food consumption may have additional benefits, such as reducing the risk of allergic disease and of overweight and obesity. However, the evidence is not conclusive, as consumers of organic food tend to have healthier lifestyles overall. Still, some experimental studies suggest that animals fed identically composed feed from organic or conventional production show differences in early development. Whether these findings are of any relevance to human health is unknown.
One possibility is the composition of organic and conventional crops can differ, but again the evidence is limited. A slightly higher content of phenolic compounds in organic fruit and vegetables is probably not important. Likewise, organic milk and dairy products often have a higher content of omega-3 fatty acids compared to conventional products. However, our main intake of essential fatty acids comes from seafood and certain nuts and oils, and a small contribution from organic dairy is of negligible relevance to human health. More important is the uptake of cadmium from mineral fertilizers used for conventionally grown cereals and other crops, but research support is inconclusive. Further, the wide usage of antibiotics in conventional animal production as a key driver of antibiotic resistance, and the restricted antibiotics use in organic production is therefore another likely advantage.
Now back to the pesticides. In organic agriculture, the use of pesticides is restricted. Certain compounds like copper sulfate and citronella are allowed according to EU regulations on organic farming. They are of little health concern. When reports occasionally appear on pesticide contents of organic produce, even in baby food, a possible explanation is that fraudulent mislabeling has occurred.
The main source of pesticide exposure is residues in conventional fruits and vegetables. This is clear from several studies of exposure levels based on urine analyses before and after study participants changed from conventional to organic food. Several epidemiological studies have reported adverse effects of certain pesticides on children’s cognitive development in relation to the mother’s pesticide exposure during pregnancy, and experimental studies support this evidence. Still, current exposures are generally regarded safe by regulatory agencies. However, the limits for pesticide residues in food are based on animal testing only of single compounds. If at all included in the testing, rodent brains are far less complex than human brains and far less sensitive than we are in regard to adverse effects on brain development. The report therefore recommends pregnant women to favor organic fruits and vegetables.
The report to the EU Parliament includes an outline of policy options without making any specific recommendations. While application of organic production methods has some advantages, some may be achieved by changing conventional production by using, e.g. integrated pest management.
The report was recently featured at a Harvard University web page, and the accompanying Facebook message elicited some dissenting comments (and many likes). Yes, organic food is often more expensive, and it is less efficient that modern chemical-supported agriculture. But why is a recommendation from scientists to protect the next generation’s brains against pesticides at all controversial? It is now up to the EU Parliament to figure out how to proceed.