With the recent release of a new review in the American Journal of Clinical Nutrition, it now seems pretty well established that organic foods aren’t any nutritionally better than regular, conventional foods. But one of the comebacks we often hear from skeptical consumers (mostly parents of small children) goes something like this: “Well, maybe that’s true, but going organic helps American farmers abandon the use of harmful pesticides.” Really? Let’s take a closer look and see if organic myths match up with reality.

First, can Certified Organic farmers use pesticides on their Certified Organic crops? Absolutely. Organic production doesn’t allow synthetic pesticides, but they can use “natural” pesticides. What’s a natural pesticide? Common examples include pyrethrins (an extract from the chrysanthemum flower), rotenone (found in roots and stems of several plants), and Bacillus thuringiensis (a nasty bacterium found in soil). Guatemalan farmers have even used fermented urine. So if you think that organic apple doesn't need to be washed, think again.

And are organic pesticides safer and better for us than synthetic pesticides? Not really: Pyrethrins have been linked to tumors in rats. Rotenone has as well (although evidence is somewhat limited),and it’s also been found to cause damage to cells and DNA.

It’s also worth noting that organic pesticides aren’t as efficient as their more modern counterparts. National Review writer John Miller noted back in 2004:

Organic food products also suffer from more than eight times as many recalls as conventional ones. Some of this problem would go away if organic farmers used synthetic sprays — but this, too, is off limits. Conventional wisdom says that we should avoid food that's been drenched in herbicides, pesticides, and fungicides. Half a century ago, there was some truth in this: Sprays were primitive and left behind chemical deposits that often survived all the way to the dinner table. Today's sprays, however, are largely biodegradable. They do their job in the field and quickly break down into harmless molecules.

What’s the end result of using less-efficient “natural”pesticides? There are still going to be pests, so organic farmers have to apply more of these chemicals. “[T]he typical organic farmer has to douse his crops with it as many as seven times to have the same effect as one or two applications of a synthetic compound based on the same ingredients,” wrote Miller.

Should we be worried about exposure to these or other organic pesticides? Or synthetic pesticides, for that matter? Let’s add a little context.

Dr. Bruce Ames, who invented a test bearing his name that screens for potential carcinogens, threw cold water on chemical/cancer scaremongering back in 2000. In a paper co-authored with the director of the Carcinogenic Potency Project at UC-Berkeley, Ames wrote that we take in plenty of chemicals that we don’t realize are even there:

About 99.9 percent of the chemicals humans ingest are natural. The amounts of synthetic pesticide residues in plant food are insignificant compared to the amount of natural pesticides produced by plants themselves. Of all dietary pesticides that humans eat, 99.99 percent are natural: they are chemicals produced by plants to defend themselves against fungi, insects, and other animal predators….

Americans eat about 1,500 mg of natural pesticides per person per day, which is about 10,000 times more than the 0.09 mg they consume of synthetic pesticide residues.

So repeat this three times: “It’s the dose that makes the poison.” Many of these pesticides (both synthetic and organic) are pumped into rats in abnormally large doses to determine their lethality and toxicity—in other words, at levels far, far higher than how consumers usually encounter them.

There’s certainly nothing wrong with buying organic. But since the supposed health benefits don’t measure up, it’s hard to say whether consumers should believe that a warm, fuzzy feeling is worth the extra cost in a $5 tomato.