Organic products — from food to skin-care nostrums to cigarettes — are very much in vogue, with the global market for organic food alone now reportedly exceeding US$60 billion annually. The views of organic devotees seem to be shared by the European Commission, whose official view of organic farming and foods is, “Good for nature, good for you.” However, there is no persuasive evidence of either.
A meta-analysis last year of data from 240 studies concluded that organic fruits and vegetables were, on average, no more nutritious than their cheaper conventional counterparts; nor were they less likely to be contaminated by pathogenic bacteria like E coli or salmonella — a finding that surprised even the researchers.
“When we began this project,” said Dena Bravata, one of the researchers, “we thought that there would likely be some findings that would support the superiority of organics over conventional food.”
Many people purchase organic foods in order to avoid exposure to harmful levels of pesticides. However, that is a poor rationale. While non-organic fruits and vegetables had more pesticide residue, the levels in more than 99 percent of cases did not cross the conservative safety thresholds set by regulators.
Moreover, the vast majority of the pesticidal substances found on produce occur “naturally” in people’s diets, through organic and conventional foods. The biochemist Bruce Ames and his colleagues have found that “99.99 percent [by weight] of the pesticides in the American diet are chemicals that plants produce to defend themselves. Only 52 natural pesticides have been tested in high-dose animal cancer tests, and about half  are rodent carcinogens; these 27 are shown to be present in many common foods.”
The bottom line is that natural chemicals are just as likely as synthetic versions to test positive in animal cancer studies, and “at the low doses of most human exposures, the comparative hazards of synthetic pesticide residues are insignificant.” In other words, consumers who buy expensive organic foods in order to avoid pesticide exposure are focusing their attention on 0.01 percent of the pesticides that they consume.
Ironically, in both Europe and North America, the designation “organic” is itself a synthetic bureaucratic construct — and it makes little sense. It prohibits the use of synthetic chemical pesticides, with some pragmatic exceptions. For example, the EU’s policy notes that “foreseen flexibility rules” can compensate for “local climatic, cultural, or structural differences.” When suitable alternatives are lacking, some (strictly enumerated) synthetic chemicals are allowed.
Similarly, in the US, there is a lengthy list of specific exceptions to the prohibitions. However, most “natural” pesticides — as well as pathogen-laden animal excreta, for use as fertilizer — are permitted.
Another rationale for buying organic is that it is supposedly better for the natural environment. However, the low yields of organic agriculture in real-world settings — typically 20 to 50 percent below yields from conventional agriculture — impose various stresses on farmland and increase water consumption substantially. According to a recent British meta-analysis, ammonia emissions, nitrogen leaching and nitrous-oxide emissions per unit of output were higher in organic systems than in conventional agriculture, as were land use and the potential for eutrophication — adverse ecosystem responses to the addition of fertilizers and wastes — and acidification.