New review of the available research confirms organic plant-based foods usually more nutritious.

It is a perennial and slightly tiresome debate, but it just won�t go away. The debate about whether organic food is more nutritious than conventional food is just one of those constant points of argument between the organic and conventional food sectors.

There are a range of issues. It can be difficult to accurately compare the two farming systems. It is difficult to account for broader but important comparative factors such as the relative ripeness or age of the products studied � is the organic tomato as old or as young as the conventional tomato studied? Has it travelled a longer or shorter distance? What about varieties?

There are still more: Does the research compare food fresh from the field, in controlled growing conditions, or available in the supermarket?

And are we all being overly reductive in focusing on one nutrient at a time, and indeed nutrition in such detail? Does the debate on nutrition background other important debates � do we fail to take into account the bigger picture, of biodiversity levels or carbon footprints, when we focus so selfishly as humans on nutrition?

All of this said, it does genuinely seem that more and more research is coming out to suggest organic food is more nutritious, most notably the QLIF research findings from Newcastle University. People point to this as being the beginning of some evidence that organic is more nutritious. That said, many still repeat the mantra that there is no scientific data to suggest that organic is more nutritious.

Which is funny. Because most of the research on the issue says the exact opposite. Conveniently, an overview of all peer-reviewed research comparing organic and conventional foods has just been issued. Charles Benbrook led a team of researchers over a two year period into the topic.

The report, New Evidence Confirms the Nutritional Superiority of Plant-Based Organic Foods, was issued in March.

97 peer-reviewed publications from 1980 to the present were examined. Of these, the authors found enough similarities to compare 236 �matched pairs�.

Matched pairs take into account co-measurability issues. As an example, tomatoes grown organically on one farm and grown conventionally on another close by, with climate, aspect, soil types, plant genetics, irrigation, nitrogen levels and harvest practices all relatively similar.

For 61% of these 236 matched pairs, organic food was shown to have higher nutritional levels. For 8 out of 11 of the nutrients studied organic food had on average 25% higher nutritional levels.

Where conventional food scored best was for nutrients relatively commonly available � potassium, protein and phosphorous. Even where conventional scored better, the amount it scored better by was relatively low: 2/3 of these involved a superiority of below 10%.

Interestingly, where organic scored best was for polyphenols and antioxidants. There was a 10% or more superiority in the antioxidant capacity of a whooping 80% of the organic samples over the conventional.

The authors pointed out that polyphenols and antioxidant capacity is an area of growing scientific investigation, both because of improvements in the analytical tools and because of the evidence that we need these to be healthy.

According to the authors, daily intake of antioxidants and polyphenols is half what it is supposed to be, which makes this nutritional superiority of organic all the more salient.

The number of comparative studies is increasing all the time: more than 40 new studies have been published since 2001.

What�s also interesting to note is that, back then, organic was scoring better in the studies of the research anyway. Indeed two reviews of the literature were published in 2001, and both suggested that organic had higher nutritional levels.

While one was published by the Soil Association, the other was published in a peer-reviewed journal, The Journal of Alternative and Complementary Medicine. Virgina Worthington reviewed 41 studies, and found higher levels in organic produce of all of the 21 nutrients analysed. This included statistically significant higher levels of some, including iron (21% more), magnesium (29% more) and vitamin C (27% more).

And yet, some time soon, you will hear the mantra; �there is no evidence that organic food is nutritionally superior to conventional�.�

To download the Benbrook report, go to previous posting.