A new study has found that when it comes to tomatoes at least, it really may pay off to fork out for the more expensive organic produce.
Researchers from the University of Barcelona have found the pesticide-free version of the fruit contains higher levels of disease-fighting chemicals than the conventional kind.
Known as polyphenols, the chemical compounds protect plants against disease and are thought to also benefit human health.
The nutrients have a natural antioxidant effect and studies have suggested they could help halt the spread of certain cancers as well as protect against chronic conditions such as arthritis. Other research has found they can protect against heart disease due to their anti-inflammatory and anti-clotting properties.
The conclusion challenges the Food Standards Agency, which has long dismissed the health gains of organic food.
The Government’s food watchdog released a report in 2009 that said there was no ‘nutritional difference’ between organic and conventionally produced food.
The team behind the latest study analysed the chemical structure of the Daniela variety of tomato. They detected 34 different beneficial compounds in both the organic and conventional versions – far more than you would get from a food supplement. However, they found that overall the organic tomatoes contained higher levels of the polyphenols.
The scientists said this difference between organic and conventional tomatoes can be explained by the manure used to grow them.
Lead author Anna Vallverdú Queralt, said: ‘Organic farming doesn’t use nitrogenous fertilizers; as a result, plants respond by activating their own defence mechanisms, increasing the levels of all antioxidants.’
Co-author Rosa M. Lamuela, added: ‘The more stress plants suffer, the more polyphenols they produce.’
The researchers said further clinical studies are needed to see if the organic tomatoes have a more potent effect on the body than the conventional type.
A team led by Ms Lamuela, had previously proved that organic tomato juice and ketchup contains higher polyphenol content than juice and ketchup made from conventionally grown tomatoes.
Tomatoes are known as a super-food as they also contain high levels of vitamin C.
The latest study was published in the Journal of Agricultural and Food Chemistry.
Peter Melchett, Policy Director, Soil Association, said: ‘The study by the University of Barcelona which shows that organic tomatoes contain higher levels of antioxidants than non-organic tomatoes confirms a major meta-analysis of all research comparing beneficial nutrients in organic and non-organic food by Dr Kirsten Brandt and others at the University of Newcastle, published in May 2011.’