 Organic kiwis win out
US researchers claim to have proved that organically grown fruit is healthier than that grown in the conventional way. |
 US researchers claim to have proved that organically grown fruit is healthier than that grown in the conventional way. The organic versus conventional debate has raged for years, and comparative studies have often proved inconclusive. Now Maria Amodio and Adel Kader of the University of California, Davis, say that they have shown organically grown kiwi fruit contains more health-promoting factors than those grown under conventional conditions.
Levels of polyphenols were significantly higher in the organically grown fruit. Antioxidant activity was higher, as were levels of ascorbic acid (vitamin C) and important minerals (Journal of the Science of Food and Agriculture DOI 10.1002/jsfa.2820).
Kader says that previous comparative studies were confounded by differences in cultivars and climatic conditions and did not include phenolic compounds in the comparison.
Kader’s team carried out a like-for-like analysis of kiwis grown next to each other on the same farm at the same time, in the same environmental conditions. A broad spectrum of characteristics from shape to detailed nutrient composition was recorded.
Levels of sugars and organic acids were similar, which means flavour would be similar. But organic fruits were darker and had thicker flesh, differences that are likely due to organic fruit having to fight pests in the absence of pesticides. A thicker skin, for example, would deter insects. Higher antioxidant activity is thought to be a natural by-product of stress.
However, some people are still unsure about the potential benefits of these compounds. Carl Winter, director of the FoodSafe Program at UC Davies, said increased nutrient and antioxidant levels may not have any health benefit and could have unknown negative effects. ‘The authors also did not look for any plant secondary metabolites of potential toxicological impact,’ he said.
According to the Soil Association, organic food sales in the UK increased by 30% to £1.6bn in 2006. The world market for certified organic foods was estimated to be worth US $23-25bn in 2003 and is growing approximately 19% every year, making these products the fastest-growing sector of the global food industry.
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