If you "wash" your apples by wiping them on your shirt—or even rinsing them in tap water—a new study suggests a more rigorous way to remove pesticides from your fruit.
In a new study published in the Journal of Agricultural and Food Chemistry, researchers applied high concentrations of two common pesticides—a fungicide called thiabendazole and an insecticide called phosmet—to organic Gala apples. After the chemicals sat for 24 hours, the researchers tried three different washing methods: tap water, a 1% baking soda and water mixture and a Clorox bleach solution similar to that used by commercial fruit producers.
They monitored the pesticide levels on the surface and inside of the fruit after washing with each method. The baking soda and water solution beat out both bleach and tap water after two minutes of cleaning, and again after eight minutes. After 12 to 15 minutes of washing, the formula had removed virtually all external pesticides, as well as some that had begun to seep below the fruit's surface. The very lengthy washing wiped out 80% of the thiabendazole and 96% of the phosmet.
"If factory washing [with bleach] is already effective, then we don't need to care about washing at home, right? But it turns out that factory-level washing is not effective," says study author Lili He, a food scientist at the University of Massachusetts, Amherst. "At home, the simplest way to wash is with tap water, but we also found that just tap water is not that effective. To reduce further pesticide exposure, we suggest adding a little baking soda."
Apples rank high on the Environmental Working Group's list of fruits with the highest levels of pesticide residue. While these chemicals are EPA-approved and thought to be safe in low doses, some research suggests it's difficult to accurately assess their impact on health over time, leading many consumers to want to limit exposure as much as possible.
While it's unlikely that most people will have the patience to let their snack sit in baking soda for 15 minutes, He says that adding a sprinkle to your regular rinse is better than nothing. (She also notes that the fruit you buy from the supermarket may start out with fewer pesticides on the surface than the apples included in the experiment.) Peeling your fruit also helps, but doing so will deprive you of valuable fiber, vitamins and minerals found in the skin.
"The fruit peel is what has the highest concentration of nutrients, but it's also what has the most pesticides," He says. "There's always two sides of the story."