You may have heard about this “Swedish study” that have followed changes in pesticides detected in urine in a family of five, measured pesticides residues in urine during 1 week of conventional food and 1 week on “organic foods”.
The study was requested by Coop Sverige AB, a grocery chain store operating in Europe but mostly in Denmark, Sweden and Norway. The PDF copy can be found here.
Because of course Coop ordered the study, they have to push it on their website (in Swedish): https://www.coop.se/Vart–ansvar/Ekoeffekten/
The study rushed to conclude that eating conventional foods leads to residuals pesticides but eating organics will reduce your amount of pesticides detected in urines. The study appears nice and makes an argument for buying organics. If it was not branded as a scientific study, it would be a nice PR move for the company. But scientifically, this study is simply a scientific fraud as it is filled with experimental flaws and a good dose of scientific dishonesty.
If there is something I hate foremost, is the blatant conflict of interest. First you demonize the target of your attack (in this case conventional farming), induce fearmongering in scientifically illiterate population (having no fundamental knowledge of pharmacology and toxicology to understand the data) and discretely appears as the savior by boasting your products are safe and natural. Does not sound like snake oil tactics?
Lets go through this study and explain what is wrong with that study:
1. A ridiculous sample size. n=1 or when the anecdote becomes law in pseudosciences
This study focuses on a family of five, including two adults and three children. Because drug ADME (absorption, distribution, metabolism, elimination) is different between sex and age, it can influence the results. Not saying even about population polymorphism in Drug Metabolism/Pharmacokinetic (the variation in the DMPK can be so important that their resulting graphs is usually referred as the “spaghetti-plot”), making conclusion on a single observation by an age-matched, gender-paired observation is anecdotical at best, fallacious at worst. Based on how this study is sold to the general public, those who made conclusions on these anecdotes is simply a scientific fraud.
2. A poor experimental design, in which the authors omitted important controls parameters to make the study scientifically sound
An important criteria when you want to test an hypothesis is to have a proper experimental design. Because research on human beings require a lot of oversight by institutional review boards, as well as a consent forms. One experimental approach used in DMPK studies is to use your volunteers as their own controls, if you have several drugs or doses you want to try, you have to have a “washout” period that will consist in a period in which volunteers will be off their treatment to allow drugs to clear off their body.
In this study, the authors completely ignored such fundamental aspect and did not apply this washout period between switching the diet. They have the volunteers on their conventional food diet for a week, immediately followed by organic diet for a week and then another conventional diet for a week. In this study only urine was used as endpoint, that is fair game and not invasive. Here below is their experimental design, the only thing I can say is it rather confusing.
They do the sampling during the conventional period, then starts the organic without sampling, leaving a period of no-sampling. This is not a wash-out, this is an experimental flaw. A real wash out would have asked the participant to not eat any fruits and vegetables for one week, then start the organic diet.
The second problem is that the authors never mentioned how they designed the two diets, or simpler the food baskets for the family. A key missing point would have been to design a defined fruits and vegetables diet identical between conventional and organics with exactly the same type and quantity, only the farming techniques differing. Also the authors should have measured the levels of pesticides in the raw, washed or peeled fresh produce to have a better comparison and also assessing the bioavailability of these pesticides.
3. If you want to measure pesticides levels, you have to consider ALL pesticides used, including those used in organic farming: Organic food IS NOT PESTICIDE-FREE.
The EU is probably the most stringent entity in terms of organic food labelling. Its directives are so stringent that even some anti-GMO activists and organic promoters like Jose Bove (he became famous for sacking a McDonalds in France in 1999 and for destroying GMO crops used by academic researchers through the Institut National de Recherche Agronomique) called the need for some relaxing clauses as cited in the Euractiv site (http://www.euractiv.com/sections/agriculture-food/eu-reforms-organic-farming-301321).
Here are his comments, as published on the website:
Excessive regulation fears
Germany, Europe’s largest organic food market, is wary of the proposal. “I would not like to see crushing bureaucratic restrictions imposed on organic farmers”, stated German Minister for Agriculture Christian Schmidt, asking decision makers to “use common sense”.
French agricultural cooperatives share these fears. “Despite a bit of progress, […] many provisions will jeopardise the development of organic agriculture” claims Coop de France.
Farming co-ops denounced the end of export diversity, which “will reduce converstions to organic farming and slow down the boom of agro-ecology”. They also criticise annual testing and the end of exemptions.
José Bové, the French Green MEP, highlights the need to harmonise support to organic farmers in the EU. He fears the cost of new restrictions, making specific reference to tests for the presence of pesticides. Bové highlights the difficulty of producing organic products without the presence of pesticides, especially when neighbouring plots are using them.
“We must take into account how difficult it is to produce organic food, when conventional farmers nearby do not take measures to prevent polluting your plot. The costs of extra testing cannot be borne by organic farmers alone. It makes more sense to apply a “whoever pollutes pays” principal when traces of pesticides are found” explains José Bové.
He continues: “The economic responsibility of unintentional pollution caused by exterior sources can lead to removing products or economic losses to organic farmers. They must be protected and compensated by those at the origin of the damages.”
You cannot grow organics without pesticides because we will not able to ensure appreciable yields. But what was interesting was his concern about the rising costs due to the leglislations about testing the presence of pesticides in organic crops. You cannot exclude that you may have contaminations from nearby conventional crops, but calling your products “pesticides-free” is a clear fallacious statement lead to misinform consumers.
Another problem is the absence of toxicity data on pesticides used in organic farms. As noted in the European Food Safety Agency 2009 report (http://www.efsa.europa.eu/en/efsajournal/pub/2430.htm)
There was up to that time of report no established EU database that assessed the toxicity (as defined as maximal residue level, an index for pesticide safety in food products) for organic products. In particular this passage is fairly intrguiging: “The following substances were found in organic samples, even if their use was not allowed in organic production: chlormequat, fenbutatin oxide, MCPA and MCPB, mepiquat, methabenzthiazuron and propamocarb. Also residues of CS2 – which is an indicator for the presence of pesticides belonging to the group of the dithiocarbamates – were found. However, since some crops contain natural compounds which also release CS2 during the chemical analysis the results cannot prove beyond doubt that dithiocarbamate pesticides were used.”
The problem is there is not accessible database to know which pesticides are tolerated for use in organic farming, unless you dig in and rely on a 2009 directive that can be downloaded here.
Here is a montage of the Annex II containing the list of pesticides allowed by the EU:
There is a clear difference between NO pesticides and usage of pesticides. Yet the study limited the investigation on pesticides used in conventional crops:
We can argue that several of these “organic farm” pesticides are inorganic compounds that maybe washed off during processing, yet there are several that are complex enough to be analyzed using conventional analytical chemistry.
Having such a selective approach on the type of pesticides is not only a experimental flaw, it is academic dishonesty and blatant scientific misconduct.
4. There are some pesticides residues in conventional fruits and vegetables, yet there presence remains marginal and well below the MRL
In this graph they have plotted the ration between the estimated daily intake (EDI) and the acceptable daily intake (ADI). A ratio of 1 means the level of EDI is 100% equal of the ADI, whereas a negative ratio means its amount was below quantifiable levels to make sense and just been detected (there is a difference in analytical chemistry between detection and quantification). With a exception of some outliers like the chlormequat (CC), most of these were not significant and were not enough to be quantified. In other means, the amount of pesticides residues were so low that the risk is near zero.
Again, here we will never know how much of pesticides used in organic crops were indeed bioavailable and biotransformed, as well as any studies relative to their toxicity.
5. Conclusion of the study, a biased conclusion based on weak evidence
Here is the original conclusion:
“The results of this study indicate that exposure to pesticides reduces when we eat organic products instead of conventionally grown food, and clarifies the significance of food as a source of exposure to chemicals. In this study we have been able to determine that the concentrations of selected pesticides decreased by an average of a factor of 9.5 when the family switched to organic food, which probably means that their total chemical load decreases. In relative terms, the children’s load decreased more than the adults’ in the food switch, probably due to their higher food intake relative to their body weight. The same exposure to chemicals results in higher concentrations of chemical residues in the bodies of children than in adults (Swedish Chemicals Agency 2014). Choosing organic foods not only reduces the levels of a number of pesticides that we are exposed to through what we eat, but also reduces the risk of a long-term impact and combination effects. We also help to reduce the spread of chemicals in the environment, and protect those who work in the cultivation of fruit and vegetables. Considering that in our day-to-day lives we are exposed to a considerable number of other chemical substances depending on our choices of food, cleaning products, shampoo, furniture, and other items, it is difficult to make a complete assessment of how much the total chemical load decreased. A more comprehensive study in which exposure to a greater number of chemical substances is examined in a greater number of individuals is required in order to make such an assessment”
The problem with this conclusion? Make a statement on a deeply-flawed study.
This would be a better conclusion that would be more scientifically accurate and in agreement with the data:
In this study, we investigated the presence of pesticides in a unmatched family sample following a conventional and organic diet. We detected the presence of different pesticides in the urine of our participants, yet the origin and the bioavailability remains unknown due to the presence of major experimental flaws. We observed notable different in pesticides metabolite profile between the different volounteers, yet we cannot attribute such changes due to age or sex, as we poorly designed the food comsumption in our samples.
Furthermore, we focused our attention on pesticides used in conventional crops yet we failed to report quantitative analysis of pesticides residues commonly found in organic crops, in particular pesticides approved by the European Commission on organic crops.
We cannot exclude an higher amount of pesticide exposure as organic crops are commonly associated with lower yields, as well as relevant toxicology data on these pesticides. Altought we detected the presence of metabolites following conventional food consumption, its detection levels were below quantification in the majority of the assay and there well below the recommended guidelines by EFSA. There we cannot conclude yet about the beneficial effects of organic consumption in terms of environmental risks due to pesticides exposure.
It is therefore important to re-explore this study with appropriate controls, redesign the experimental plan and analytical approach as well as increase our sampling population to ensure an objective study that can provide a scientific rationale on this question: are organic foods safer than conventional foods?
Conflict of Interests:
This study has been ordered by Coop Sverige AB, a grocery chain store company. Because Coop Sverige policy is focused on the sales of organic foods, we have to disclaim a possible conflict of interest that may impact the statements and conclusions made in this report.
6. A pesticide is a pesticide, doused on conventional foods or organic foods
If you are still skeptical about this blog and organics are still healthier than conventional produce, you may want to read this blog post they dive in further details on pesticides in organic foods.