Is organic food a waste of money?
“Organic” is just one of the many labels thrust on the socially conscious, along with “carbon-neutral”, “eco-friendly”, “green”, “fair-trade” and “ethical”. Such labels are powerful marketing tools for the relevant industries, and people are even prepared to pay more if they feel they are doing good, particularly for their health. But are the claimed benefits backed up by evidence and should we be sceptical?
The organic food industry continues to grow in the UK, where it is now worth more than £2 billion, and the same is true globally. Organic food is produced according to industry standards, but is it better for you? Small studies have made various claims about its superior nutrient content and its health benefit, but so far a good-quality review of available evidence has been lacking. Well, I saw the news tonight; that review has now been done, and it is bad news for the organic foodies. A team from the London School of Hygiene and Tropical Medicine was commissioned by the Food Standards Agency to search through over 52 000 articles from the last 50 years. They found 160 relevant studies, 55 of which were of sufficient quality to be included. They found “no evidence of a difference in 8 of the 11 nutrient categories (vitamin C, phenolic compounds, magnesium, potassium, calcium, zinc, copper, and total soluble solids)” between organic and non-organic food. Phosphorus was higher in organic food but nitrogen content was higher in non-organic food, and these differences are likely to be due to the fertilizers used during production. The report concludes that there is unlikely to be a health benefit based on the similar nutrient content of organic and non-organic food. The Soil Association, unsurprisingly, want more longitudinal research.
It is quite fitting that this week’s BMJ included a piece about how citing evidence in scientific articles can actually have a negative impact on the scientific truth due to biases among authors, research institutions and journals. The same must be true for messages in the media. If we hear that organic food is good for our health often enough, we start to believe it.