Organic food is no better for you than the traditionally grown even though it may taste better, say researchers.
Despite the perception that organic food grown without artificial fertilisers, pesticides and other chemicals, is more pure, nutritious and virtuous, scientists have said there is little evidence that it is healthier.
There are no convincing differences between organic and conventional foods in nutrient content or health-benefits
A review of 237 research studies into organic food found the products were 30 per cent less likely to contain pesticide residue than conventionally grown fruit and vegetables but were not necessarily 100 per cent free of the chemicals. They found no consistent differences in the vitamin content of organic products.
There were higher levels of phosphorus in organically grown food but the researchers said this was of little importance as so few people were deficient in this. The only other significant finding was that some studies suggested organic milk contained higher levels of omega-3 fatty acid, which is thought to be important for brain development in infants and for cardiovascular health. Dr Crystal Smith-Spangler, of Stanford’s Centre for Health Policy, said “we were a little surprised” by the results but that people should eat more fruit and vegetables, no matter how they are grown, because most Western diets are deficient.
Dr Dena Bravata, a fellow researcher, said that, beyond their perceived health benefits, people also bought organic products because of taste, concerns about the effects of conventional farming practices on the environment and animal welfare. The research was published in the Annals of Internal Medicine journal.
The group cited two studies comparing children consuming organic and conventional diets, which found lower levels of pesticide residue in the urine of children on organic diets, though the levels of pesticides in both groups of children were below safety thresholds.
Organic chicken and pork also appeared to reduce exposure to antibiotic-resistant bacteria, but the researchers said the health implications of this were not clear. The group said the research was difficult because of the various ways organic food was tested, other factors that affect nutrient levels such as soil and weather, and the effect that organic farming methods may have.
Prof Alan Dangour, a senior lecturer at the London School of Hygiene and Tropical Medicine, said the review showed that “there are no convincing differences between organic and conventional foods in nutrient content or health-benefits”.
A spokesman for the Soil Association claimed that the method used by the researchers was not suitable for comparing crops, while a previous study had found that the differences in nutrients between organic and conventional produce were “highly significant”. He said a Dutch study, mentioned in the review, found that children aged two were 36 per cent less likely to develop eczema, if more than 90 per cent of the dairy products they consumed were organic.