Costly organic vegetables are no better for your health than those
grown conventionally, a study has found.
A two-year experiment which involved scientists growing potatoes,
carrots and onions under both organic and traditional conditions has
found that the health-giving properties of each are virtually
identical. The chemical compound in vegetables that fights cancer,
heart disease and dementia was found to be present in virtually the
same amounts in both types.
However, the Irish Organic Association last night
said the study, which was carried out by environmental scientists in
Denmark, was not relevant to organic production in Ireland. The group
insisted that organic food produced here is healthier because our soil
is kept more fertile by rotating crops.
Boffins at the University of Copenhagen cultivated a total of 72 plots
of land, half using traditional farming methods, including treating
them with pesticides, non-organic fertilisers and added nutrients. The
other half were farmed organically, under conditions recommended by
various organic food organisations, which involved using natural aids
such as manure instead of fertiliser.
The result was that there was little difference in the amount of the
key compound, polyphenols, in either the onions or the carrots, though
there was a slightly higher level in organic potatoes than in
conventional ones. Crops were grown at different times of year and in
different parts of the country because factors like the type of soil,
the difference in climate and attacks by pests are major factors in
the amount of
polyphenols produced by plants.
Although levels of polyphenols have been shown to protect against
cancer cells in laboratory tests, it is still unclear whether these
antioxidants have the same beneficial effects when taken into the body
in food. Last night, the Irish Organic Association
(IOFGA) said Danish organic farming was different from that here.
Grace Maher, development officer at the Association, said that unlike
in Denmark, soil in Ireland is kept fertile by rotating crops. “Crop
rotation is an integral part of organic farming. It is essential to
prevent the build-up of pests and disease in the soil, but it is also
important as it means that nutrients are not continually being
depleted from the soil. This means that nutrients are readily
available in the soil for crops to absorb.”
She added: “This is an isolated study and our research has shown that
the main reasons people buy organic food is that it is free from
pesticides, free from GM materials. It also has high animal welfare
standards and is climate friendly. We also believe that organic food
is more nutritious.”
She also insisted that organic produce can be cheaper if consumers
“On the issue of cost, organic food is extremely cost competitive and
fruit and vegetables bought in season are often cheaper than
conventionally produced food, particularly if sourced directly from
The latest study is published by the Journal of Agricultural and Food