There is very little that distinguishes organic food from conventional food. In an attempt to follow the pervasive “good food vs. bad food” storyline, many people have grossly exaggerated the differences between organic and conventional foods leaving readers with few facts grounded in scientific evidence. Don’t let the top three misperceptions about organic and conventional food influence your food choices.
This post covers:
- Pesticide residues on food and human safety
- Organic foods, conventional foods and the environment
- Nutrition differences between organic and conventional foods
This post does not cover worker safety or in-depth environmental issues.
#1 Myth: Organic Foods are Grown Without Pesticides
Both organic and conventional crops are sprayed with pesticides, compounds that control a variety of pests (1, 2). In fact there is a long list of substances, including pesticides, allowed for use on organic farms. The differentiating factor between organic and conventional farming is the source of pesticides. Organic farmers primarily use naturally occurring pesticides in addition to a small number of man-made pesticides while conventional farmers primarily use man-made pesticides.
In some instances there is a man-made form of a compound identical to the one found in nature. For instance, methyl bromide, a fumigant gas used to kill fungi, nematodes and weeds, is found in nature and also made in a lab. Both conventional and organic farmers can use methyl bromide on strawberry plants. Bacillus thuringienis, the most commonly used organic pesticide, is both naturally occurring and man-made; incorporated into some genetically engineered foods. One is natural, one is man-made yet there is no detectable difference between the two (3).
#2 Myth: Organic Foods are Safer for Human Consumption and Better for the Environment
Compounds found in nature are not automatically safe and non-toxic, or safer than man-made compounds (4, 5). Both naturally occurring compounds and man-made chemicals are completely harmless, extremely toxic at a certain dose, or fall somewhere in between these two extremes. You’ve probably heard the saying “the dose makes the poison.” Many compounds we consume every day, from vitamin A to water, can be lethal if consumed in extremely high doses. The same is true for pesticides. Dose and length of exposure determine toxicity. Our government has several safeguards in place for the use of pesticides. First, the EPA evaluates all pesticides. Prior to use in the United States pesticides must be free from unreasonable risk to human health or the environment. Regardless of the type of pesticide used, whether organic or man-made, the Environmental Protection Agency limits the amount of pesticide residues allowed in food and water. The USDA Pesticide Data Program routinely monitors pesticide residues in foods and has found pesticide residues, whether organic or conventional, “pose no safety concern” (8, 9).
Organic pesticides are also not necessarily better for the environment, though they are considered safe in the amounts used (just like man-made pesticides). As an example, rotenone, a naturally occurring compound used in fisheries and can be fatal if inhaled (staff spraying this pesticide must be protected from risk of inhalation) and kills fish within an hour of spraying. Waters treated with rotenone are closed for public swimming for several months after treatment allowing dead fish time to decompose. When used according to instructions, rotenone poses “no overall risk to human health” or the environment (6). In addition, a study in soybeans found organic pesticides did not control aphids (plant lice) as effectively as man-made pesticides and they were more detrimental to the environment (partly due to the amount that needed to be used) (7).
There are environmental effects, both good and bad, from conventional and organic farming. Organic farming has advanced nonchemical methods of pest control and in some instances improved soil quality while decreasing soil erosion. However, organic farming also produces a lower yield, which means more environmental resources are used to produce the same total amount of food.
Can’t we farm without any pesticides?
Sure. Some conventional and organic farms do not use pesticides. A conventional farm may choose not to get organic certification, even if they don’t use any pesticides, because of the cost of certification. Keep in mind pesticides help get rid of pests and, can therefore help make food safer by the decreasing the likelihood of pathogens such as E. coli through use of anti-microbial compounds (10, 11).
What about the “Dirty Dozen”, Should I Steer Clear of the Foods that have the Most Pesticide Residues?
Some groups rank foods based on total pesticide residues – foods that are the “most contaminated.” Though some foods may have more pesticide residues on them than others, a study from the University of California Davis found all 12 commodities identified in the Dirty Dozen contained pesticide residues well below the established safe level (called the chronic reference doses or RfDs for short). In fact, only one pesticide residue, found on bell peppers, exceeded 1% of the RfD, coming in at 2%. So the largest total “dose” of a pesticide residue found was still 50 times lower than the established safe dose. Three quarters of the pesticides detected were at levels 1,000 times below the RfD. Therefore, the 12 foods listed on the Dirty Dozen “most contaminated” foods pose “negligible risks” for consumers. Choosing organic over conventional to avoid the fruits and vegetables on the Dirty Dozen will not completely negate your exposure to pesticides (because some organic produce has pesticide residues as well) or lower your risk from exposure to pesticides because your risk is negligible to begin with (12). Given the low amount of pesticide residues found on conventional and organic produce, there’s little appreciable difference in total pesticide exposure, whether you eat conventional or organic.
Though some studies, as well as pesticide monitoring programs have found conventional produce contains significantly more total pesticide residues then organic produce, significantly more than a miniscule amount is still a miniscule amount. Here’s an analogy: if I give you one penny and give your friend 2 pennies, your friend has 100% more money than you do – that’s a statistically significant difference. However, the financial impact of two pennies vs. one penny is meaningless.
If you want to add up your total exposure, check out the Alliance for Food and Farming developed a pesticide calculator and research behind the calculator:
#3 Myth: Organic Food is More Nutritious
Several studies have examined nutrient differences between organic and conventionally produced foods. Most of this research shows no appreciable difference in vitamin or mineral content or health effects. What about plant compounds including antioxidants? In some cases organic farming may improve antioxidant content while in others man-made pesticides actually increase concentrations of certain beneficial plant-based compounds (13, 14).
In a world where we have many food choices and an overabundance of incorrect nutrition information, it’s easy to grasp onto a concept that isn’t evidence-based. Don’t get caught up in the hype and instead look for the scientific details. When it comes to organic and conventional foods, you’re not stuck choosing sides but instead can enjoy both – there is no appreciable difference in pesticide residues or nutrition content between the two.
Disclosure: I am an advisor for USFRA. All opinions expressed are my own after taking my typical nosedive into the scientific literature and government regulations on this subject.
1 Types of pesticide ingredients. US Environmental Protection Agency.
2 Food and Pesticides. US Environmental Protection Agency
3 Koch MS, Ward JM, Levine SL, Baum JA, Vicini JL, Hammond BG. The food and environmental safety of Bt crops. Front Plant Sci 2015; 6: 283.
4 Pesticides – What’s my risk? National Pesticide Information Center.
5 Contaminants Found in Groundwater. The USGS Water Science School. http://water.usgs.gov/edu/groundwater-contaminants.html
6 Lake and stream rehabilitation: rotenone use and health risks. Washington department of fish and wildlife. http://wdfw.wa.gov/licensing/sepa/2016/16041_2002_fseis.pdf
7 Bahlai CA, Xue Y, McCreary CM, Schaafsma AW, Hallett RH. Choosing Organic Pesticides over Synthetic Pesticides May Not Effectively Mitigate Environmental Risk in Soybeans. PLoS One 2010; 5(6): e11250.
8 What Consumers Should Know. 2014 Pesticide Data Program Annual Summary. United States Department of Agriculture. https://www.ams.usda.gov/sites/default/files/media/PDP%202014%20Annual%20Summary%20Consumers.pdf
9 Pesticide Program Residue Monitoring. US. Food and Drug Administration. http://www.fda.gov/Food/FoodborneIllnessContaminants/Pesticides/ucm2006797.htm
10 Mukheriee A, Speh D, Dyck E, Diez-Gonzalez F. Preharvest evaluation of coliforms, Escherichia coli, Salmonella, and Escherichia coli O157:H7 in organic and conventional produce grown by Minnesota farmers. J Food Prot 2004;67(5):894-900.
11 Johannessen GS, Bengtsson GB, Heier BT, Bredholt S, Wasteson Y, Rørvik LM. Potential uptake of Escherichia coli O157:H7 from organic manure into crisphead lettuce. Appl Environ Microbiol 2005;71(5):2221-5.
12 Winter CK, Katz JM. Dietary Exposure to Pesticide Residues from Commodities Alleged to Contain the Highest Contamination Levels. J Toxicol 2011; 589674.
13 Dangour AD, Lock K, Hayter A, Aikenhead A, Allen E, Uauy R. Nutrition-related health effects of organic foods: a systematic review. Am J Clin Nutr 2010; 92(1):203-210.
14 Rosen J. A Review of the Nutrition Claims Made by Proponents of Organic Food, Comprehensive Reviews in Food Science and Food Safety 2010;9(3): 270-277.