Press comment: American study of organic food

04 September 2012

Though this US study is of limited application in Europe, we are pleased to see that it recommends organic food as a way for people to avoid pesticides in their food. Indeed, this remains consumers’ top reason for choosing organic. The report, in fact, contains a number of extremely positive findings about organic food, including the recognition that organic milk has significantly higher levels of beneficial nutrients or that the risk of bacteria resistant to 3 or more antibiotics was higher in non-organic than in organic chicken and pork.

Unsurprisingly, perhaps, the focus is placed on highly contestable negatives over incontrovertible positives, such as reduced chemical use, exclusion of controversial additives such as aspartame and MSG, higher animal welfare and increased biodiversity, to name a few.

The report and its methodology, however, is flawed and actually serves to highlight the difficulty – if not impossibility – of accurately measuring the human health benefits of one type of food over another. For example, the study only reviewed some existing studies, and omitted many, including all those not written in English. The scientific methodology used for the review, while suitable for comparing trials of medicines, is not right for comparing different crops. A medicine used in Scotland is expected to behave in exactly the same way as the same medicine used in California, but potatoes grown in different climates and soils will be different. Studies that treat crop trials as if they were clinical trials of medicines, like this one, exaggerate the variation between studies, and drown out the real differences. A UK review paper, using the correct statistical analysis, has found that most of the differences in nutrient levels between organic and non-organic fruit and vegetables seen in this US study are actually highly significant.

As the study says, there are almost no long-term studies of the impact on people’s health of eating organic food, but the study does mention one Dutch Government funded long-term research project, which found that children who consumed dairy products of which more than 90% were organically produced had a 36% lower risk for eczema at age 2 years.