In a potential blow to the organic food industry, a major new study by scientists from the University of Oxford has revealed there is little or no evidence that eating food which is free from pesticides will lessen a woman's risk of developing cancer.
Researchers from Cancer Research UK recorded the dietary habits of some 600,000 women aged 50 of over for a period of nine years, of whom some 50,000 women developed some form of cancer.
When comparing the incidence of cancer in women who usually or always ate organic food and those who never ate organic, they found virtually no difference.
The study, published in the British Journal of Cancer, discovered that women who mainly or always eat organic are actually more likely to develop breast cancer, but less likely to develop non-Hodgkin lymphoma.
However the difference in rate was so small scientists believe the variation could be due to chance or similar factors.
There have long been concerns that the use of pesticides in farming can lead to cancer, but so far scientists have been unable to establish a firm link – particularly as the fruit and vegetables to be found on supermarket shelves will have very small amounts of pesticides on them, if indeed any at all.
Dr Claire Knight, Cancer Research UK's health information manager, said:
"This study adds to the evidence that eating organically grown food doesn't lower your overall cancer risk. But."
The organic food industry is now worth an estimated £1.79 billion in sales, according to the Soil Association, and sales of organic food grew by 2.8% last year.
Much of this increase is due to what supermarkets call a "Jamie (Oliver) Generation" of ethically-aware under-35s, many of them concentrated in London and the south-east, who purchase organic food for a number of factors apart from health, including environmental sustainability, animal welfare concerns and a dislike or distrust of larger, corporate manufacturers.