I've been hearing a lot of headlines over the last few days about a newly released study comparing the nutritional quality of organically grown foods to that of conventionally grown foods. Until today all I had heard was the big headline "New study shows organic produce to be no better for you than conventionally grown produce." A headline very similar to this was running on NPR.
I knew I had to learn more about this study. I immediately bristled at this headline and am concerned about the impact such headlines could have. Just a few minutes into my own 'research' and I was feeling a bit better about the reality behind those headlines. The UK study conducted by the London School of Hygiene & Tropical Medicine, and published July 29 in The American Journal of Clinical Nutrition, is based on a close examination of 162 previously published articles from a 50 year period, starting in 1958 and leading up to February 29th, 2008. 50,000 papers were looked at and of these the researchers deemed 162 to be relevant and in the end only 55 of those were deemed rigorous enough to be included. From all that I have now read the conclusions drawn by these researchers may not match the full scope of their findings. More than that, the media has been trumpeting headlines that dismiss all conflicting evidence even perhaps from within this very study. And yes, I know this is what media headlines do.
All the same, here are a few ways the type of head line I mentioned above is problematic...
1. The study did not look at chemical residues or other contaminants
2.The study only looked at Nutrient differences for the 13 most commonly reported nutrient categories.
3. There actually seems to have been some significant differences in 2 of the 13 nutrients in addition to what this research team deemed "nutritionally insignificant" differences in the other 10 nutrients. At issue here for me is the history of science claiming to know the full scope of nutrients and nutrient levels needed to meet all of our bodies needs. What seems to follow is the discovery of previously unknown, but necessary elements of our natural diet, or the realization that previously known but disregarded minerals, acids and nutrients are far more important than once thought.
A response written by The Organic Center states in part that "The London team reported finding statistically significant differences between organically and conventionally grown crops in three of thirteen categories of nutrients. Significant differences cited by the team included nitrogen, which was higher in conventional crops, and phosphorus and tritratable acids, both of which were higher in the organic crops. Elevated levels of nitrogen in food are regarded by most scientists as a public health hazard because of the potential for cancer-causing nitrosamine compounds to form in the human GI tract. Hence, this finding of higher nitrogen in conventional food favors organic crops, as do the other two differences.
Despite the fact that these three categories of nutrients favored organic foods, and none favored conventionally grown foods, the London-based team concluded that there are no nutritional differences between organically and conventionally grown crops."
In response to the amount of criticism leveled against this study, Tim Smith, the Chief Executive of the Food Standards Agency ( the agency ultimately responsible for the UK Study) has written an open letter to interested parties about the independent organic review. In part, his letter states that "The Food Standards Agency would like to set the record straight, following publication of the study last week that compared the nutrient content of organic food with conventionally produced food. This review was commissioned by us to ensure that our position on organic food is up to date and reflects the weight and balance of current scientific evidence. This research had also been called for by the organic sector to review emerging research in this area.
Pesticides were specifically excluded from the scope of this work. This is because our position on the safety of pesticides is already clear: pesticides are rigorously assessed and their residues are closely monitored. Because of this the use of pesticides in either organic or conventional food production does not pose an unacceptable risk to human health and helps to ensure a plentiful supply of food all year round."
To Read the full response to the UK study from The Organic Center click Here.
To Read an informative article concerning this study by Paula Crossfield in the Huffington post , click here. ( This one is good and full of links to information on other recent studies)
To Read the Science Daily Article Click Here. ( A general sort of media response)
To Read a response by Marion Nestle click Here.
Finally, To read the post that I think really hit the nail on the head read This.