The debate over the nutritional differences between organic and non-organic foods has been reignited with the publication of a study carried out by an international team of experts.
In the largest study of its kind to date, led by Newcastle University, researchers analysed already published scientific investigations from around the world which looked at the differences between organically and conventionally grown crops.
The report found that the bulk of the studies showed that organic crops had nutritional benefits – contradicting the last major study of this type, carried out in 2009 by the Food Standards Agency.
Analysing 343 different studies which looked at compositional differences, the team said that switching to organic fruit, vegetable and cereals could provide additional antioxidants equivalent to somewhere between 1-2 extra portions of fruit and vegetables a day.
It also found that organic foods were between 18 and 69 per cent higher in a number of key antioxidants than conventionally grown crops and were likely to be lower in pesticide residues.
The study, which was published in the British Journal of Nutrition, also found significantly lower levels of heavy metals in organic crops.
Newcastle University’s Professor Carlo Leifert, who led the research, said: “This study demonstrates that choosing food produced according to organic standards can lead to increased intake of nutritionally desirable antioxidants and reduced exposure to toxic heavy metals.”
However, the Crop Protection Association (CPA), the voice of the UK plant science industry, called into question the significance of the findings.
Nick von Westenholz, the organisation’s chief executive, said: “Whilst this study points to slightly higher levels of antioxidants and lower levels of pesticide residues in organic produce when compared to conventional, these differences are relatively small, for example, a typical residue of 0.1mg/kg is equivalent to a fly on a ten ton truck.”
He said that the important issue was that people should have a healthy, well-balanced diet which was high in fruit and vegetables, whether conventionally grown or otherwise.
“Over 97 per cent of UK farms are conventional and these farms produce crops that are healthy, affordable and safe. It is important that consumers aren’t given unnecessary cause for concern that my lead to them questioning the safety of their food and reducing their consumption of fruit and vegetables as a result, potentially causing a health deficit.”
Stating that organic systems had been shown to be 34 per cent lower yielding, he said that the use of pesticides in conventional agriculture helped support healthy choices by ensuring consumers had access to a “safe and affordable” source of fruit and vegetables.
But the chief executive of the Soil Association, Helen Browning, welcomed the report as confirming “what many consumers thought”. She said: “We know that people choose organic food because they believe it is better for them, as well as for wildlife, animal welfare and the environment, and this research backs up what people think about organic food,
“In other countries there has long been much higher levels of support and acceptance of the benefits of organic food and farming: we hope these findings will bring the UK in line with the rest of Europe, when it comes to both attitudes to organic food and support for organic farming.”