Editor's note: This is the last in a series on organic and conventional foods.

In the previous two installments we have seen that certified organic (CO) foods are cultivated with the use of pesticides in a similar manner to conventional foods. As a result, the myth that CO foods are pesticide-free can be abandoned. But the belief that CO foods deliver less pesticides to children is not the only reason parents choose to pay more for CO labeled products. Other firmly held beliefs include CO foods as sources of better nutrition, being tastier than conventional, and are more beneficial to the environment.

Marketing for organics focuses on promoting the image of a healthier lifestyle. This includes the idea that organic foods deliver better nutrition. Aside from small exceptions, this has not been shown to be the case, according to a comprehensive analysis of existing studies comparing organic and conventional foods from Stanford University. Eating a conventional apple will not yield fewer nutritional components than its organic counterpart.

We have to also remember that vitamin deficiency is not a big scourge in pediatric health in America. Even if CO produce delivered more vitamins, our children are usually not deficient in these nutrients to begin with. Parents are generally better advised to ensure their children are eating copious amounts of fruits and vegetables rather than focus on farming methods.

Conversely, there are reasons to be weary of organic produce. Jon Entine, a senior fellow at the Institute for Food and Agricultural Literacy, says the Stanford study also found "that E.coli and other pathogen contamination is more likely in organic than conventional produce." Between 1990 and 2001, more than 10,000 people fell ill due to foods contaminated with pathogens, and many have organic foods to blame. One study found E. coli in produce from almost 10 percent of organic farm samples, but only 2 percent of conventional ones.

This sentiment was echoed by Penn State's College of Agricultural Science in a 2014 article which stated, "Organic farmers and processors do not have the arsenal of preventive measures available that conventional farmers and processors do, so spoilage and pests can be a bigger issue."  Recently, Chipotle, the ubiquitous Mexican fast-food chain was plagued with contamination issues despite a staunch commitment to CO foods.

Another widespread belief is that CO produce is beneficial to the environment based on marketing messages that invoke images of farming via "natural" methods. In reality, the organic industry takes a toll on the planet no smaller than conventional farming's methods. CO foods not only use pesticides, but often must use larger amounts of approved non-synthetic agents to achieve pest control.

As Kavin Senapathy author of The Fear Babe writes, "We should all be concerned about the well-being of our environment. But organic foods do not contribute to a healthier ecosystem, though it is a very pervasive myth. We know that on average, organic farming yields are lower than their conventionally-farmed counterparts...around 20 to 50 percent lower than conventional agriculture. Further, conventional farming enables better carbon sequestration, and reduces soil erosion."

A large study published in the prestigious journal Nature in 2012 agrees with Senapathy. It concluded that "...overall, organic yields are typically lower than conventional yields" ranging from 5 to 34 percent lower yields based on the system and site characteristics. Yield is an environmental concern because the more land needed to produce a commodity, the larger the negative environmental impact.

Lastly, supporters of organics often speak of their higher quality and better taste. Very little true science is available regarding this matter. There is one small, but well conducted study from the University of Gävle in Sweden in which participants were asked to compare two identical slices of banana given two different labels: "eco-friendly" (the term for organic there) and "conventional". Participants tended to assign better taste scores to the "eco-friendly." Unknown to them, the slices all came from the same conventional banana. For a humorous, but poignant take on this experiment, take a look at this excerpt from a popular Penn and Teller show.

Labeling foods with special, descriptive words such as "Certified Organic", "all natural" or "local" has long been a powerful tool for marketers. The way foods are labeled has powerful implications on sales, and not one of us is immune to these convincing forces. Director of the Cornell Food and Brand Lab, Brian Wansink, PhD, and his team, have demonstrated multiple times that small changes in menu item names can mean bigger profits. In one study, a change such as "Homestyle Chicken Parmesan" instead of "chicken parmesan", influenced 27 percent more diners to pick the more descriptive items. In addition, they were willing to pay 10 percent more for those items.

Ultimately, the choice to spend up to double for food that is designated "Certified Organic" is a personal choice. No matter what the evidence shows, some parents feel more comfortable feeding their children CO products. As consumers, however, it is generally a wise approach to understand the difference between real science-based benefit and clever marketing.

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