Currently, this video is making its way around social media.
It shows a Swedish family that switches from eating conventionally produced food to an all-organic diet. The video claims that pesticide residues in the urine of each of the family members were reduced after 2 weeks of the organic food diet. While I am all for healthy eating and think organic food is great, I was a little skeptical of the ideas that were being pushed in this short clip. Do pesticides residues actually drop that quickly when switching to organic food? Also, it was funded by Coop Sverige AB, a large Swedish supermarket and retail chain, that may have some vested interest in the outcomes of this research. The research group that actually carried out the testing and reporting is the IVL Swedish Environmental Research Institute. According to their website they are an “independent, non-profit research institute, owned by a foundation jointly established by the Swedish Government and Swedish Industry. I am not familiar with this research group, but one would hope that they are unbiased. The viral video is pretty vague, but a more detailed report is freely available, so I delved a little further to see what it had to say.
The researchers sampled urine from a family of 4 for a three-week period. The first week was a continuation of their normal diet that did not include much organically produced food. During the second week they switched to an all-organic diet. The twelve pesticides measured are shown in the table below.
* indicates that a metabolite of the original compound was actually measured in urine
During the non-organic diet phase of this experiment 8/12 analyzed pesticides were detected in at least one urine samples at median concentrations shown in the figure below. Note that concentrations of these pesticides in urine were still well below levels deemed safe (See Figure 1). Pesticide residues are reported as μg/g creatinine as they are standardized to creatinine levels in urine to standardize for different levels of hydration in individuals at different times.
After the period of consuming only all organic food only 5/12 pesticides were detected in each urine sample and they were found at much lower levels (See Figure 1).
Figure 1: Concentrations of pesticides in urine before and after an organic diet in a family of 4
The study is fairly well documented although it would be good to see the methods critiqued and go through the peer review process. However, the science seems pretty sound. The sample size of only 4 individuals in one family is fairly small. Overall, the results make sense in that if you reduce exposure to synthetic pesticides by consuming organic foods your body burdens of those chemicals should decrease over time. The amazing thing to me is that this was detectable after just a two-week switch to organic foods.
Does it matter?
I think it is great if we can reduce the amounts of pesticides we use and our exposures to them. However, remember that even before switching to the organic diet pesticides residues were well below acceptable levels. Also, organic foods do contain “natural” non-synthetic pesticide residues. A 2012 Scientific American article by Christie Wilcox summarizes the scientific evidence on whether reducing pesticide loads by eating organic foods has health benefits compared to consuming conventionally produced foods and concludes that it does not. However, we still have little idea how these individual chemicals act in complex mixtures within our bodies.