Eating organic food could have benefits for health, researchers at a North university have found.

A study by Dr Kirsten Brandt at Newcastle University used analysis of organic carrots, apples and potatoes to reveal greater concentrations of vitamin C and chemicals that can protect the body against heart attacks and cancer.

The research could challenge official Government guidelines which say that there is no evidence of organic food being healthier than conventional produce.

That guidance led Environment Secretary and South Shields MP David Miliband to say that organic food was a “lifestyle choice”, though he later added that he ate organic food because of its taste and environmental benefits. But Dr Brandt’s findings will lend scientific weight to the widely-held view that organic food is good for people.

Dr Brandt said: “My research shows that there are benefits. The reason why it’s such a grey area is because it’s extremely difficult to measure the health benefit in any food, but we can say that if you eat 400g of fruit and vegetables per day you would get 20% more nutrients in organic food.”

The new studies found that organic tomatoes had more vitamin C, beta-carotene and flavonoids, which are known to have benefits in the fight against cancer and heart disease, though they also had less lycopene, which is thought to help prevent skin ageing, diabetes and osteoporosis. Organic apple puree was found to contain more phenols, flavonoids and vitamin C than conventional versions.

Dr Brandt – who grows her own vegetables on her allotment at Nafferton, Northumberland – hit the headlines two years ago when she published research that claimed eating carrots could help reduce the risk of cancer.

Sales of organic food rose by 30% last year but until now the health benefits of organic food have been the subject of intense debate, with the Advertising Standards Agency advising against claims of nutritional benefits and the Food Standards Agency cool on those claims.

Peter Melchett, policy director of the organic food pressure group the Soil Association, said: “There is clear evidence that a range of organic foods contain more beneficial nutrients and vitamins and less of things known to have a detrimental health effect such as saturated fats and nitrates.”

By Graeme Whitfield, The Journal