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
Eighty-five percent of Americans are concerned about pesticides in produce,1 and rightly so. The US uses about 1.1 billion pounds of pesticides each year,2 and it's not uncommon for your apple or strawberries to contain two different pesticides… or more.
The US Department of Agriculture (USDA) insists pesticide residues on food are no cause for concern, even though more than half of all foods tested last year had detectable levels.
While tolerance levels are set that determine upper allowable limits for individual pesticides, there is no legal limit on the number of different pesticides allowed on food. So lurking in your fruit cocktail is probably also a chemical cocktail…
"The effect of these mixtures is untested and unknown," according to Urvashi Rangan, Ph.D., a toxicologist and executive director of the Consumer Reports Food Safety and Sustainability Center.
Buying Organic Is the Simplest Way to Cut Down on Pesticides in Produce
Ideally, all of the produce you eat would be organic. The largest study of its kind found that people who "often or always" ate organic food had about 65 percent lower levels of pesticide residues compared to those who ate the least amount of organic produce.3
Research also found that organic produce had, on average, 180 times lower pesticide content than conventional produce.4 That being said, not everyone has access to a wide variety of organic produce, and it can sometimes be costlier than buying conventional.
One way to save some money while still lowering your risk is by focusing on purchasing certain organic items, while "settling" for others that are conventionally grown.
Animal products, like meat, butter, milk and eggs, are actually the most important to buy organic, since animal products tend to bioaccumulate toxins from their pesticide-laced feed, concentrating them to far higher concentrations than are typically present in vegetables.
Unlike conventional fruits and vegetables, where peeling and washing can sometimes reduce the amounts of these toxins, the pesticides and drugs that these animals get exposed to during their lives can become incorporated into their very tissues, especially their fat. So if you're on a budget, choose organic animal foods first.
Difference Between Organic and Conventionally Grown
In order to be certified organic, a food must be grown without the use of synthetic pesticides. However, certain natural pesticides, and a few synthetic ones, are allowed, even in organic farming.
Yet, the differences in their use and safety in organic farming versus conventional are vast. According to Michael Sligh, a farmer, founding chairman of the National Organic Standards Board, and Just Foods Program director at Rural Advancement Foundation International:5
"Before a pesticide is even approved for use in organic farming, it must be evaluated for potential adverse effects on humans, animals, and the environment, and prove it's compatible with a system of sustainable agriculture.
And farmers must follow integrated pest-management plans that require that they use any approved organic pesticide as a last resort and develop strategies to avoid repeated use."
Cheat Sheet: Which Produce Should You Buy Organic?
Beyond animal foods, the pesticide load of different fruits and vegetables can vary greatly. Consumer Reports analyzed 12 years of data from the USDA's Pesticide Data Program to determine the risk categories (from very low to very high) for different types of produce.
Because children are especially vulnerable to the effects of environmental chemicals, including pesticides, they based the risk assessment on a 3.5-year-old child. They recommended buying organic for any produce that came back in the medium or higher risk categories, which left the following foods as examples of those you should always try to buy organic.
What Are the Health Risks of Pesticide Exposure?
One commonly used type of pesticide, organophosphates, were first developed as nerve gas during World War II. They work by inhibiting cholinesterase, an enzyme that regulates a key messenger in your brain called acetylcholine.
In effect, these poisons disrupt the signals between neurons, an action that has been linked to neurodegenerative diseases like Alzheimer's disease and Parkinson's in humans. In children, there is increasing evidence that these pesticides are especially damaging, not only at high exposure levels but also at low, chronic levels to which millions are exposed.
For instance, researcher has revealed 11 pesticides that inhibit the aldehyde dehydrogenase (ALDH) enzyme and increase the risk of Parkinson's disease.6 The effects were seen even with very low-level exposure – levels lower than those currently being used in everyday applications.
When working properly, ALDH changes aldehydes, which are toxic to dopamine cells, into less toxic compounds. When ALDH is blocked, however, this transformation does not occur, contributing to the development of Parkinson's.
Separate research has further revealed that ambient exposure to organophosphate pesticides also increased the risk of developing Parkinson's disease.7 Rotenone and paraquat are two additional pesticides linked to an increased risk of Parkinson's disease, and both are lipophilic, meaning they resist breaking down in water and accumulate in your fat. Both are also known to cross your blood-brain barrier.
Pesticides Are Harming Kids' Brains
The CHAMACOS Study also showed that very small amounts of pesticides may be harming kids' brains. It followed hundreds of pregnant women living in Salinas Valley, California, an agricultural mecca that has had up to a half-million pounds of organophosphates sprayed in the region per year.
The children were followed through age 12 to assess what impact the pesticides had on their development.8 It turns out the impact was quite dramatic, and mothers' exposure to organophosphates during pregnancy was associated with:9
- Shorter duration of pregnancy
- Poorer neonatal reflexes
- Lower IQ and poorer cognitive functioning in children
- Increased risk of attention problems in children
Research published, ironically, the same day as the CHAMACOS study also found that prenatal exposure to chlorpyrifos (Dursban, a pesticide once used to control cockroaches in inner cities) was associated with lower IQs and poorer working memory in three-year-olds.10
A senior scientist at the Natural Resources Defense Council, who is now an official at the California Environmental Protection Agency (EPA) said the combination of studies come "about as close as I can imagine to absolute proof" of the damaging effects of pesticides on children's brains.11
It is this cumulative effect of numerous chemicals, particularly to developing children, that likely poses the greatest risks of all. Brenda Eskenazi, chief investigator of the CHAMACOS study, noted:12
"The other thing we don't know about is the combined effect of exposures… Throughout the course of a day, people may eat several different types of produce, each of which may bear traces of one or more pesticides. They encounter other types of chemicals as well—from antibacterials in soaps, to plasticizers in foodware, to flame retardants in the furniture… By day's end, you've got a combination of chemicals and an unknown level of risk."
The USDA Doesn't Test for the Most Commonly Used Pesticide
Most people are aware that there might be pesticide residues on conventionally grown produce, but you might not think about the pesticides in processed foods, particularly in ingredients like genetically modified (GM) corn and soy, which are heavily sprayed with the herbicide Roundup. Glyphosate is the active ingredient in Monsanto's Roundup herbicide and may be at least partially to blame for rising rates of numerous chronic diseases in Westernized societies, according to research published in Entropy.13
Authored by Dr. Stephanie Seneff, a research scientist at the Massachusetts Institute of Technology (MIT) and Anthony Samsel, a retired science consultant, the report argues that glyphosate residues "enhance the damaging effects of other food-borne chemical residues and toxins in the environment to disrupt normal body functions and induce disease." In a study published in 2013, researchers also concluded that glyphosate is a xenoestrogen that is functionally similar to estradiol, the most potent human estrogen, and concentrations in the parts-per-trillion range had carcinogenic effects.14
In fact, in a study published in The Lancet, scientists convened by the World Health Organization found that glyphosate is "probably carcinogenic to humans."15 Among the data cited:16
- Glyphosate exposure for farm workers causes "increased risks of non-Hodgkin lymphoma that persisted after adjustment for other pesticides."
- Glyphosate "induced DNA and chromosomal damage in mammals, and in human and animal cells in vitro"
- "Increases in blood markers of chromosomal damage" were noted in residents of farm communities after spraying glyphosate
How much glyphosate is in your food? No one knows because the USDA does not test for it. As reported by Reuters:17
"As has been the case with past analyses, the USDA said it did not test this past year for residues of glyphosate, the active ingredient in Roundup herbicide and the world's most widely used herbicide. A USDA spokesman who asked not to be quoted said that the test measures required for glyphosate are 'extremely expensive... to do on an regular basis'... Many genetically modified crops can be sprayed directly with glyphosate, and some consumer and health groups fear glyphosate residues in foods are harmful to human health, even though the government says the pesticide is considered safe."
Monsanto, meanwhile, has petitioned the US Environmental Protection Agency (EPA) -- and received approval! -- to increase the allowable limit of glyphosate residues on crops like GM soy and canola from 20 parts per million (ppm) to 40 ppm.18 In case you missed it, that's doubling the amount of pesticide residues allowed in your food.
Pesticides Contributing to Antibiotic-Resistant Disease and Killing Bees
Pesticides are impacting human health on multiple levels. One of the latest studies revealed that exposure to herbicides widely used on GM crops (including glyphosate, dicamba and 2,4-D) alters how susceptible disease-causing bacteria are to antibiotics, in many cases making them more antibiotic-resistant.19,20 The researchers explained:
"Increasingly common chemicals used in agriculture, domestic gardens, and public places can induce a multiple-antibiotic resistance phenotype in potential pathogens. The effect occurs upon simultaneous exposure to antibiotics and is faster than the lethal effect of antibiotics.
The magnitude of the induced response may undermine antibiotic therapy and substantially increase the probability of spontaneous mutation to higher levels of resistance. The combination of high use of both herbicides and antibiotics in proximity to farm animals and important insects, such as honeybees, might also compromise their therapeutic effects and drive greater use of antibiotics."
Meanwhile, chemical giant Bayer has been marketing two of its pesticide formulations – Calypso and Lizetan – as "not toxic to bees," even though they contain a neonicotinoid (Thiacloprid), which has been found to harm bees. Bayer attempted to sue the Friends of the Earth organization for claiming Thiacloprid harms bees, but a judge recently dismissed Bayer's suit.21 As reported by The Ecologist:22
"A paper published in the journal PLOS ONE confirms that Thiacloprid, along with the neonicotinoids Imidacloprid and Clothianidin, affects bees' navigational ability and behavior, making it harder for them to find their way back to their hives.23 It also shows that exposure to Thiacloprid can increase the likelihood of honeybees dying if they are already infected with diseases. A further study found that the toxicity of Thiacloprid to honey bees is increased over 1,000 fold when mixed with fungicides."
How to Minimize Your Dietary Pesticide Exposure
Your best bet for minimizing health risks from pesticide exposure (even those the government claim are "safe") is to avoid them in the first place by eating organic as much as possible and investing in a good water filtration system for your home or apartment. Alternatively, you can try growing some of your own produce using organic methods right in your own backyard. If you know you have been exposed to pesticides, the lactic acid bacteria formed during the fermentation of kimchi may help your body break down pesticides. So including fermented foods like kimchi in your diet may also be a wise strategy to help detox the pesticides that do enter your body.
One of the benefits of eating organic is that the foods will be free of GM ingredients – and this is key to avoiding exposure to toxic glyphosate. Following are some great resources to obtain wholesome organic food. Eating locally produced organic food will not only support your family's health, it will also protect the environment from harmful chemical pollutants and the inadvertent spread of genetically engineered seeds and chemical-resistant weeds and pests. Finally, if you can't find organic produce, don't use that as an excuse to skimp on veggies altogether. As Consumer Reports noted:24
"Though we believe that organic is always the best choice because it promotes sustainable agriculture, getting plenty of fruits and vegetables—even if you can't obtain organic—takes precedence when it comes to your health."
Also remember that some local foods are grown using organic standards, even though they might not be certified organic. One of the benefits of getting your food straight from the farm via the resources below is that you can often meet the farmer and ask about pesticides and other chemical usage:
- Alternative Farming Systems Information Center, Community Supported Agriculture (CSA)
- Farmers' Markets -- A national listing of farmers' markets.
- Local Harvest -- This Web site will help you find farmers' markets, family farms, and other sources of sustainably grown food in your area where you can buy produce, grass-fed meats, and many other goodies.
- Eat Well Guide: Wherever you are, Eat Well -- The Guide is a free online directory of more than 25,000 restaurants, farms, stores, farmers' markets, CSAs, and other sources of local, sustainably produced food throughout the US.
- Community Involved in Sustaining Agriculture (CISA) -- CISA is dedicated to sustaining agriculture and promoting the products of small farms.
- FoodRoutes -- The FoodRoutes "Find Good Food" map can help you connect with local farmers to find the freshest, tastiest food possible. On their interactive map, you can find a listing for local farmers, CSAs, and markets near you.