Nicholas B. Tiller

The blog that unifies scientific skepticism, critical-thinking, health & fitness, and the exercise sciences

  • Nicholas B. Tiller Ph.D.

#51: Is organic food better for you? Let's look at the data

Organic food is produced in farming systems that are free from man-made (synthetic) fertilizers, pesticides, growth regulators, and livestock feed additives. In recent years, there’s been a dramatic surge in the sale of organic foods: in the US alone, revenue increased from $3.6 billion to $43.4 billion from 1997 to 2015.

Organic food is marketed principally on a logical fallacy called the appeal to nature, in which one asserts that a practice is necessarily good or better because it is natural. This exploits our bias for natural products, but it doesn’t speak to the purported healthful nature of organic foods, nor is it a valid reason for integrating organic food into a healthy-eating regimen.

A survey presented at the annual meeting of the American Agricultural Economics Association reported that 69% of consumers who regularly bought organic foods did so because they perceived it to be healthier. This is relevant because such a perception unequivocally contributes to sales. Moreover, the claim appears to partly justify the higher costs, and is likely pertinent for exercisers interested in healthy-eating and athletes looking to augment their sporting performance. But the healthful nature of organic food is a fact-based claim that has been empirically tested, and found wanting.

A 2010 review of literature synthesized 50 years of published studies (from 1958 to 2008), engaged in correspondence with subject experts, and hand-searched bibliographies. It concluded that “evidence is lacking for nutrition-related health effects that result from the consumption of organically produced foodstuffs”. The conclusion corroborates that of another systematic review published a year earlier by the same group, in which 55 studies deemed to be of appropriate quality were collated; this also concluded that “there is no evidence of a difference in nutrient quality between organically and conventionally produced foodstuffs”.

There have been suggestions that perhaps organic foods contain greater micronutrient concentrations than those grown non-organically, but such observations do not reflect scientific consensus. Another systematic review from 2012 showed that any differences in biomarker and nutrient concentrations between organic and non-organic foods were not significantly or clinically meaningful.

It’s worth correcting a common misconception surrounding organic food that it’s pesticide-free, but this isn’t so. Pesticides are necessary for healthy crop growth, maximizing crop productivity by controlling pests like weeds, insect infestations, and diseases. The label pesticide-free stamped on organic food is a misnomer because organic crops are grown using organic pesticides (i.e. those derived from natural sources), as opposed to conventional farming which makes use of synthetic pesticides. Regulators only test for the latter, which allows manufacturers of organic produce to circumvent the regulations.

It’s true that some data indicate a lower risk of contamination from detectable pesticides in organic foodstuffs; however, it’s unlikely that there are differences in terms of the risk of exceeding the maximum allowed limits of exposure. Pesticide use is highly regulated by the government (for both organic and non-organic methods), and neither farming method yields produce that exceeds the safe upper-limit.

An investigation in the 1990s compared crop health between an organic pesticide (rotenone-pyrethrin) and a non-organic soft synthetic pesticide (Imidan). While two applications of Imidan produced the desired outcomes, an equivalent level of protection required seven applications of rotenone-pyrethrin. Although environmental impact wasn’t assessed, it’s plausible that the natural pesticide may have been more harmful given that it required more than three times the number of applications. It’s unfortunate that regulatory bodies don’t screen for organic pesticides.

To wrap it up, if someone chooses to eat organic because they perceive it to have a superior taste, then fair enough. It’s a subjective claim that cannot be tested. There is also some suggestion that organic is more environmentally friendly, but the arguments for this are complex and controversial. Nevertheless, on two key aspects, the research is conclusive: (1) organic foods are no more healthful than non-organic foods; and (2) there is no difference in health risk from organic versus non-organic pesticide exposure.

From what I can tell, the popularity of organic food appears to hinge largely on the fallacious appeal to nature, which itself exploits a simple cognitive bias that humans have for natural produce. The fact that consumers still perceive organic foods as more healthful, despite the data to the contrary, represents a victory for marketing over science.