Rinsing an apple under the kitchen tap may remove dirt.
However, new research suggests that adding baking soda to the water is the best way to remove pesticide residue.
The researchers from the University of Massachusetts compared three different methods for washing apples.
They included tap water, a tap water and baking soda solution, and a commercial bleach often used on produce.
They found the 1 percent baking soda and water solution to be the most effective at reducing pesticides.
“Tap water can remove some pesticide residues, but adding some baking soda to the tap makes it more powerful,” Lili He, PhD, an author of the study and assistant professor in the Department of Food Sciences at the University of Massachusetts, told Healthline.
Pesticides can assist with increasing crop yield by preventing bugs, bacteria, and mold.
But concerns have been raised over the potential health effects of pesticides on humans who eat the produce.
Previous studies by He found that pesticides can penetrate into plant tissues, making it difficult to wash pesticides away.
How the study was conducted
In this study, He and her colleagues sought to examine the best method to remove such pesticides.
They applied two commonly used pesticides to organic Gala apples.
They then washed the apples using each method for two minutes at a time.
After that time period, the baking soda solution had been the most successful at reducing pesticide residue.
It took around 12 to 15 minutes for the baking soda solution to remove 80 percent of one form of the pesticide and 96 percent of the other.
The U.S. Department of Agriculture’s Pesticide Data Program collects data on pesticide residues in food.
The most recent data available, from the 2015 annual report, found that when pesticide residue is found on food, it’s almost always at a level below the tolerances set down by the Environmental Protection Agency (EPA).
More than 99 percent of the products sampled by the Pesticide Data Program had residue below the EPA tolerance levels.
Pesticides and produce
Lauri Wright, PhD, an assistant professor in public health at the University of South Florida, says consumers shouldn’t be worried about pesticides on their produce.
“Pesticides present on fruits and vegetables pose little to no health risk due to low levels of pesticides actually on those foods. Pesticides help to keep destructive pests away from crops, which results in more plants surviving and a larger harvest. Greater harvest mean that there is a greater availability of fruits and vegetables and the prices are lower. Because of the minimal health risks associated with pesticide use and close monitoring, the pros outweigh the cons,” Wright told Healthline.
She added the greatest risk for consumers from unwashed fruit and vegetables isn’t from pesticides. Rather, it’s from foodborne illness.
“Consumers should wash their fruits and vegetables with a vinegar solution to decrease bacteria and prevent any illness such as E. coli,” Wright said.
The concerns remain
Kristin Kirkpatrick, MS, RD, LD, wellness manager at the Cleveland Clinic Wellness Institute, says some of her patients are still worried about the risks.
“Many of my patients ask what’s the best way to remove pesticides, and often they are buying expensive sprays that have not always seemed to do the job. This method, from He’s study, appears both effective and affordable,” Kirkpatrick told Healthline.
Kirkpatrick advises her patients to follow the guidance of The Dirty Dozen and the Clean Fifteen, lists made by the Environmental Working Group that rank fruit and vegetables most and least likely to have pesticide residue.
At the top of the Dirty Dozen list for 2017 are strawberries, spinach, nectarines, apples, and peaches.
Sweet corn, avocados, pineapples, cabbage, and onions were the top five Clean Fifteen, meaning they were least likely to have pesticides.
As for which fruits and vegetables require extra attention when washing, Wright advises to use a vegetable brush when washing produce with thick skin, and to consider throwing away the outer leaves of leafy green vegetables such as lettuce and cabbage before washing.
She also advises consumers not to wash produce immediately after bringing it home.
“The best time to wash produce is immediately before eating or cooking the product, not when it is brought home from the store. You should avoid washing and then storing produce because it creates a perfect, moist habitat for microbes to grow. This can also speed up the spoilage of produce by leaving it wet in the fridge,” she says.
Most importantly, Wright says, consumers need to understand that pesticides pose little risk to human health. They shouldn’t put people off eating fruits and vegetables.
“Fruits and vegetables are extremely important for health and preventing many conditions and disease, such as obesity and cancer. Pesticides levels are closely monitored to assure safety, so enjoy your fruits and vegetables,” she said.