WARNING!
This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.
By Dr. Mercola
Eating fresh produce is essential to staying healthy and warding off chronic disease, but if you purchase conventional varieties, you're probably getting some pesticide residues along with many of your bites.
The health effects of these residues are being debated, but considering the many health risks linked to pesticides — from infertility and birth defects to endocrine disruption, neurological disorders and cancer1 — there's good reason to keep your exposure as low as possible, including opting for organic produce as much as possible.
According to the latest pesticide residue report released by the U.S. Department of Agriculture (USDA), which used 2015 data and was released in November 2016, about 85 percent of the more than 10,000 samples they tested contained pesticide residues.2 The U.S. Food and Drug Administration (FDA) also compiled an annual pesticide residue report using 2015 data, which was released in November 2017.3 It, too, showed the majority of U.S. fruits and vegetables are contaminated with pesticide residues.
Most US Produce Contains Pesticide Residues
The FDA's sampling of nearly 6,000 foods revealed that fruits and vegetables are most frequently contaminated with pesticide residues. Notably, 82 percent of domestic fruits and 62 percent of domestic vegetables had such residues, including:4
- 97 percent of apples
- 83 percent of grapes
- 60 percent of tomatoes
- 57 percent of mushrooms
- 53 percent of plums
Among imported fruits and vegetables, 57 percent and 47 percent contained residues, respectively, and the imported varieties were more likely to contain illegal levels of pesticide residues compared to the domestic samples. Raising red flags is the fact that the neurotoxic pesticide chlorpyrifos was the fourth most-prevalent chemical in the samples out of the more than 200 pesticides detected.5
The chemical, known to disrupt brain development and cause brain damage, neurological abnormalities, reduced IQ and aggressiveness in children, has a half-life on food of several weeks, making nonorganic foods a major source of exposure. The FDA was quick to point out that "over 98 percent of domestic and 90 percent of imported foods were compliant with federal standards," but this isn't saying much if the federal standards are too lax to protect public health.
Former EPA senior scientist and director of the Program on Reproductive Health and the Environment at the University of California San Francisco School of Medicine, Tracey Woodruff, told Environmental Health News, "Risk assessment practices at federal agencies have not been updated for modern scientific principles, including accounting for the fact that people are exposed to multiple chemicals and that certain groups, such as genetically susceptible, the very young and old can be at greater risk of exposure."6
FOIA Requests Reveal 2,4-D Use Is Expected to Rise
According to Environmental Health News, an internal memo from the FDA, obtained via a Freedom of Information Act (FOIA) request, estimated the use of 2,4-Dichlorophenoxyacetic acid (2,4-D) would increase by threefold in the next year due to the approval of genetically engineered (GE) crops designed to withstand it.
The U.S. Environmental Protection Agency (EPA) approved the use of Enlist Duo — an herbicide manufactured by Dow Chemical that combines 2,4-D with Roundup, to be used on corn and soybeans genetically engineered to tolerate both 2,4-D and glyphosate — in 2014.
"The U.S. Department of Agriculture estimates that by 2020, the use of 2,4-D on America's farms could rise between 100 percent and 600 percent now that it has been approved as part of Enlist Duo," the National Resources Defense Council (NRDC) stated,7 echoing the FDA's estimate. 2,4-D is one of the ingredients in Agent Orange, which was used to defoliate battlefields in the jungles of Vietnam, with horrendous consequences to the health of those exposed.
It's also a common ingredient in "weed and feed" lawn care products, because it kills weeds without harming grass, fruits or vegetables, the latter of which makes it very popular among farmers. This is concerning because IARC ruled 2,4-D a possible human carcinogen in 2015, and there is concern it may increase the risk of Non-Hodgkin lymphoma and soft-tissue cancer known as sarcoma.
Further, it's an endocrine-disrupting chemical that may negatively affect thyroid hormones and brain development. It may also be associated with birth defects, reduced fertility and neurological problems.
How Much Glyphosate Is in Your Food?
One pesticide that's notably missing from the FDA's latest report is glyphosate, the most widely used herbicide worldwide. The agency stated that they completed preliminary testing of soybeans, corn, milk and eggs for glyphosate residues in fiscal year 2017, with plans for "expanded testing to other foods in FY [fiscal year] 2018," however as for what the results have been so far, they've only stated, "Preliminary results for glyphosate testing showed no pesticide residue violations for glyphosate in all four commodities tested (soybeans, corn, milk and eggs)."8
This is again a rather arbitrary point, since in July 2013, right in the midst of mounting questions about glyphosate's safety, the EPA went ahead and raised the allowable limits of glyphosate in both food and feed crops.9 And as reported by Environmental Health News:10
"Neither FDA nor USDA has routinely tested for glyphosate despite the fact it is the world's most widely used herbicide, and testing by academics, consumer groups and other countries has shown residues of the weed killer in food. The FDA said in early 2016 that it planned to start testing for the weed killer, and documents show that one FDA chemist reported finding residues in honey and in oatmeal products, but overall results of the program testing have not been released publicly.
Details of the testing program are being kept secret, and in the documents released by FDA through the FOIA, large blocks of information are blacked out. FDA declined to comment about the status of the glyphosate and 2,4-D testing, including when it might publish some results."
Glyphosate is used in large quantities on GE glyphosate-tolerant crops (i.e., Roundup Ready varieties), and its use increased nearly fifteenfold since 1996.11
Glyphosate is also a popular tool for desiccating (or accelerating the drying out) of crops like wheat and oats, with University of California San Diego (UCSD) School of Medicine researchers noting in JAMA that Roundup is "applied as a desiccant to most small nongenetically modified grains." So for both the GE crops and non-GE grains, glyphosate "is found in these crops at harvest."
Glyphosate Linked to Gut Disturbances, Breathing Problems
Concerns over glyphosate's toxicity have been mounting since the International Agency for Research on Cancer's (IARC) 2015 determination that glyphosate is a "probable carcinogen." But that's not the only problem. Glyphosate is toxic to many microbes as well as to most plants, and one likely effect of chronic low-dose oral exposure to glyphosate is a disruption of the balance among gut microbes toward an overrepresentation of pathogens.
A 2018 study published in Toxicology Reports revealed that long-term exposure to Roundup led to alterations in the gut microbes of rats, specifically altering the firmicutes to bacteroidetes ratio in female rats, such that firmicutes were decreased and bacteroidetes increased.12 This could have implications for how glyphosate contributes to disease, since separate research has found, for instance, that diabetics tend to have fewer firmicutes and more plentiful amounts of bacteroidetes compared to nondiabetics.13
A positive correlation for the ratios of bacteroidetes to firmicutes and reduced glucose tolerance has also been found. Further, other research has linked exposure to pesticides at work with an increased risk of breathing problems, chronic bronchitis and "symptoms that are consistent with airflow obstruction." In fact, people exposed to pesticides at work had a 22 percent increased risk of developing chronic lung disease.14
It's estimated that up to 20,000 farmworkers are poisoned by pesticides each year, although the actual number is likely far higher, as many of the workers may not seek medical care or may be misdiagnosed if they do seek treatment.15 While the FDA drags their feet on getting pertinent information on glyphosate levels in food out to the public, the Canadian Food Inspection Agency has revealed that nearly 30 percent of the more than 3,000 foods they tested contain glyphosate.16
This included nearly 37 percent of grain products, 47 percent of bean/pea/lentil products and more than 30 percent of infant food and cereal. Even 7 percent of fresh fruits and vegetables contained the residues.
Meanwhile, in the U.S. researchers tested urine levels of glyphosate and its metabolite aminomethylphosphonic acid (AMPA) among 100 people living in Southern California over a period of 23 years — from 1993 to 2016.17 At the start of the study, very few of the participants had detectable levels of glyphosate in their urine, but by 2016, 70 percent of them did.
The prevalence of human exposure to glyphosate increased by 500 percent during the study period while actual levels of the chemical, in ug/ml, increased by a shocking 1,208 percent. If you'd like to know your personal glyphosate levels, you can now find out. The Health Research Institute (HRI) in Iowa developed the glyphosate urine test kit, which will allow you to determine your own exposure to this toxic herbicide, while also participating in a worldwide study on environmental glyphosate exposures.
Going Organic Can Reduce Your Pesticide Exposure
Eating nonorganic GE foods (the prime candidates for Roundup spraying) is associated with higher glyphosate levels in your body.18 A study of close to 4,500 people in the U.S. also found that those who "often or always" ate organic had about 65 percent lower levels of pesticide residues compared to those who ate the least amount of organic produce.19
So choosing organic foods as much as possible is an important way to lower your exposure to pesticides and, in fact, avoiding pesticides is the No. 1 reason why people go organic.20 Not only do these chemicals pose a direct risk to human health, including to developing babies,21 but they also threaten the Earth as we know it. Glyphosate residues of 653 parts per billion (ppb) have even been detected in some honey samples — an amount that's more than 10 times the European limit of 50 ppb.22
Bees, as pollinators, travel from plant to plant. With grasslands being increasingly converted into GE corn and soybean fields where glyphosate and other pesticides are amply sprayed, it's easy for them to become contaminated and then transfer that contamination to their honey. Research published in the journal Nature Communications has similarly revealed that pollen collected next to corn fields is contaminated with up to 32 different pesticides.23
At this point, the effects of these chemical exposures on bees and other pollinators is unknown, but common sense would indicate that they can't be good. So remember that you are actually "voting" for less pesticides and herbicides with every organic and grass fed food and consumer product you buy. In addition, it doesn't have to be "all or nothing" — going 100 percent organic is ideal, but every organic purchase you make helps.
If you must choose between which products to purchase organic, I recommend prioritizing organic animal foods and then using the Environmental Working Group's (EWG) "Dirty Dozen" list for produce, which are among the most heavily contaminated with pesticides and therefore the most important plant foods to buy organic. As of 2017, these include:24
For the nonorganic produce you consume, washing with a solution of baking soda may help to remove some of the pesticides on the surface of the fruit or vegetable,25 although it won't remove chemical residues that have penetrated beyond the peel.
Peeling is another option to reduce pesticide residue, but this also means you're removing the healthy compounds contained in the peel (and there can still be residues that have penetrated into the produce flesh). For these reasons, the best way to avoid pesticide residues in your food is to choose those that haven't been exposed to them to begin with, i.e., go organic.