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As well as Jennifer Bowden’s columns in the NZ Listener and here at listener.co.nz, subscribers can access her fortnightly “Myth busters” column, in which she explores myths around food and nutrition. This week, she looks at whether organic food is worth the extra cost.
Organic foods have developed a near-mythical status in supermarket aisles. They’re often viewed as the holy grail of wellness, with promises of being safer, more nutritious, and better for the planet than their conventional counterparts, all of which marketers use to justify the price premium that accompanies an “organic” label.
But is it just clever marketing or is there substance behind the hype? Let’s dig into the facts and find out if organic foods live up to their wholesome reputation – or if they’re simply cashing in on a healthy-looking facade.
Organic foods are grown without most human-made fertilisers, pesticides, certain medicines (such as antibiotics), growth hormones, food additives and most synthetic chemicals. In other words, organic foods are produced through more traditional farming and food-production practices than conventional non-organic foods.
Consumers choose organic foods for various reasons, typically centred around their potential positive effects on our environment, animal welfare, human health and safety. Consumers expect organic foods to contain fewer pesticide residues than conventional foods.
While agricultural compounds, such as synthetic pesticides, are credited with improving crop yields, and thus the quantity and pricing of fresh fruits, vegetables, cereals and nuts, they also have risks.
In high doses, some agricultural compounds can cause serious damage to the nervous system, lungs, reproductive system, endocrine and immune systems and possibly cause cancer.
Long-term, low-level exposure may also be a concern. For instance, French researchers found greater exposure to pesticide residues was associated with an increased risk of developing type 2 diabetes over a four-year period. Moreover, there are real concerns about the impact of agricultural residues on infants and children who are more susceptible to chemical toxicity; exposures in childhood may have a far greater cancer risk than equivalent exposures in later life.
Not unsurprisingly, studies routinely find that organic produce has fewer pesticide residues. A 2012 systematic review, of studies published between 1966 to 2011, found that organic produce had a 30% lower risk of pesticide contamination than conventionally grown produce.
More recent reviews affirm this earlier one. At the same time, clinical trials in children and adults have confirmed that switching to an organic diet for just one week significantly reduces pesticide-residue levels excreted from the body.
Also, according to a 2022 clinical trial published in the American Journal of Clinical Nutrition, switching from a less-than-nutritious Western-style diet to the highly lauded Mediterranean diet, rich in fruits and vegetables, increased pesticide residue intake. However, switching to organic produce, irrespective of dietary pattern, reduced pesticide residue levels.
Still, contrary to popular belief, organic food does not contain more nutrients than conventionally grown foods, as verified by numerous studies. However, a large Harvard University observational study found that eating lots of fruits and vegetables with low pesticide levels (such as organic produce) was associated with greater longevity. It appeared that the higher pesticide residues in the produce may have cancelled out the health benefits of the fruits and vegetables.
Still, as an observational study, the Harvard study does not prove that pesticide levels caused a shorter lifespan, as a whole raft of other lifestyle and dietary factors could contribute to these findings.
Thus, laying the credit for increased longevity at the foot of organic foods is premature. Indeed, in 2020, an Australian review reiterated the conclusion of earlier reviews, noting that the “current evidence base does not allow a definitive statement on the health benefits of organic dietary intake”.
Ultimately, organic foods cost more, but the impact of their lower pesticide residue levels on long-term health is unclear. Moreover, organic foods do not contain more nutrients or clear health benefits compared with conventionally produced foods. Whereas we know that eating more whole foods is beneficial for your health.
So, if you want a safer bet for your food budget, focus on eating a variety of whole foods, whether organic or not, rather than a few expensive organic items.
