Bookmark and Share March 11, 2010 - Dave Mulder

Are organic foods more nutritious?

This post is the third in a series of responses to typical anti-organic, anti-local talking points. My first article asked how expensive organics are, and the second article examined the efficiency of organic farms.

Today, we will look at the nutrition of organic foods.

Critics of the organic food movement find great pleasure in claiming that organic foods are no more nutritious than conventional foods. When they cite cherry-picked studies, we intuitively raise a warning flag in the back of our mind that what they say may be total crap.

Answering a question like this one is impossible in one study; rather, we need to look at an entire collection of related studies. In research, we call this meta-analysis.

The most notable published meta-analysis to date, commissioned by the United Kingdom Food Standards Agency, found no significant differences in nutrient content between organic food products and conventional food products. This review, published in 2009, has been met with stark criticism by both foodies as well as agricultural researchers.

Without trying to get deep into the analysis, the FSA study looked through peer-reviewed journals to find original articles publishing nutrient data on organic and conventional plants. Out of nearly 200 total studies, only 50 or so passed muster. And in those 50+, the only nutrients considered were those that appeared 10 or more times.

Critics of the FSA study argue that many studies were wrongly discarded and that the authors do not really understand the inner workings of agricultural experiments. When you include some of those reports, you start to see significant effects in the direction of organic plant products.  And within the included studies, you see significant effects in nutrient levels beyond the 11 reported.

Another meta-analysis (slightly more recent than the FSA work), commissioned by France’s food safety agency, AFSSA, confirmed the beliefs of those critical of the FSA report. In addition to having fewer pesticides (94 to 100% of all organic foods have no detectable levels of pesticide), organic foods offer health benefits across the board in terms of nutrient density and diversity. Notably, organic fruits and vegetables contain more phytomicronutrients (perhaps twice as many as conventional) such as polyphenols and antioxidants. Research into physiology and biochemistry increasingly shows these nutrients playing important roles in cellular processes.

Though the nutrition of organic foods is a major point of contention right now, the scientific tide does seem to be supportive of their nutrient density advantage over conventional plant foods.

Filed under: ,