Tim's Blog

The desk review of 162 scientific papers from the scientific literature over the last 50 years was funded by the British government Food Standards Agency and published in the August 2009 issue of American Journal of Clinical Nutrition.

The researchers claim there are small nutritional benefits, but they conclude, "On the basis of a systematic review of studies of satisfactory quality, there is no evidence of a difference in nutrient quality between organically and conventionally produced foodstuffs. The small differences in nutrient content detected are biologically plausible and mostly relate to differences in production methods".

There are many problems with methodology, but here are some obvious responses:

The analysis was restricted to the most commonly reported nutrients.

This permitted the researchers to include the widest range of papers but limited the factors that could be compared. In other words, organic could have some better micronutrients, anti-oxidants or co-enzymes but not be statistically relevant

The paper completely lacks an historical perspective

Until ten years ago we didn't know what to look for, and in some cases did not have the measurement capability, and we certainly did not have the research funding to establish the benefit from organic. In the last ten years we have discovered more nutritional factors, more benefits arising from those factors, and have refined our ability to isolate and measure them.

The same study applied to the last decade would undoubtedly have a different result.

Some of the other methodological problems listed here are severely compounded by the lack of an historical view.

The paper does not consider the methodology of the original study

Measurement of nutritional value is very complex. Take this example: if we grow 3 varieties of carrot in one paddock we can get 3 different results. If we grow one variety in 3 different soil types we can get 3 different results. If we grow one variety in one soil in 3 different years we can get 3 different results. Many studies do not adequately cover these issues. Of particular relevance is that, especially before the current decade of increased awareness of organic, many studies did not define organic as certified organic. The organic industry strongly promotes certification and will only be compared on the basis of certified produce.

The conclusion too broad

The researchers have considered only some nutrients and have therefore ignored others, especially antioxidants and coenzymes, many of which will only appear in more recent papers. Further more they have not considered the other benefits of organic food, such as the absence of anti-nutritional and polluting compounds (e.g. pesticide residues), or the environmental benefits (reduce soil loss, carbon sequestration etc.), the production benefits (fewer energy dense inputs, better growth, less water use), or taste, social justice and animal welfare. Sociol factors may have direct nutritional benefits such as consumers may be much more prepared to eat whole produce (e.g. apple and potato skins) if they believe that no pesticides were used, leading to much better delivery of nutritional factors such as antioxidants (generally higher in the skin of vegetables and fruits).

Visit our Forum on "Nutrional Quality of Organic Food" to discuss this further with other members.

You can also view our Abstract article under the features section of our site.