By Shari Steinbach, MS RDN, RDBA Contributing Editor
You’ve often heard it said that “the dose makes the poison” and this is certainly an important message when it comes to understanding and communicating the ongoing debate surrounding food safety and the use of conventional versus organic pesticides. When considering the safety of substances, it is vital to understand the “dose-response relationship.” Almost every substance including water, can be poisonous at some level which indicates the hazard potential. In the United States, chemicals are regulated using a risk-based approach, where they study the exposure conditions under which a chemical causes harm. Every chemical, including all pesticides, have a dose level that will not produce a harmful response in a living organism that is based on studies to determine the No Observed Adverse Effect Level (NOAEL).
When it comes to discussing pesticide residues on fruits and vegetables with inquiring consumers, it is very important to understand the difference between a ‘hazard-based’ and a ‘risk-based’ method for evaluation. The difference lies in exposure. Since 1991, the USDA has been publishing the results of a large pesticide residue monitoring program called the Pesticide Data Program (PDP). This is the data the Environmental Working Group (EWG) uses to develop their annual publication of the “dirty dozen™” list. The EWG’s list is not a risk assessment, but a simple ranking of the presence or absence of pesticide residues. If you apply risk assessment principles to the 2016 “dirty dozen™” list you get these facts: A woman could consume 774 servings of spinach in one day, or a child could eat 340 servings of apples in one day, each without any effect, if both the spinach and apples had the highest pesticide residues recorded by the USDA for those products1. Most scientists and health experts agree that the simple presence of pesticide residues on foods does not mean they are harmful, and that both conventionally and organically grown fruits and vegetables are safe to consume.
Research indicates that fear-based messages such as that from the EWG appear to cause some low-income consumers to purchase less of both conventional and organic fruits and vegetables. An outcome that can have detrimental health effects on an already vulnerable population. The 2016 study published by Nutrition Today, also reports that most shoppers in their survey trust dietitians/nutritionists, scientists, and physicians for health and safety information about fresh fruits and vegetables. This presents an important opportunity for supermarket RDs to teach customers about best practices in handling all fruits and vegetables to minimize safety concerns and enjoy them more often. We need to translate the science, discuss produce growing practices, and communicate the health benefits of fruits and vegetables to ensure consumers are getting accurate and actionable information related to all income levels.