By Dr. Mercola
There's been an ongoing debate as to whether or not organically-grown foods are healthier than conventional varieties. Some studies have confirmed that organic foods tend to contain higher levels of nutrients like vitamins and minerals, while others found the nutritional difference between them wasn't particularly impressive.
It's important to realize that nutrient content will be largely dictated by the health of the soils in which it is grown. It's unlikely for organic foods grown in depleted soils to see a significant boost in nutrients.
Organic food is typically grown in regenerative agricultural systems that are replete with micronutrients and healthy microbes. As a result, organic produce will tend to be more nutritious than their conventional counterparts.
But another factor that comes into play in this discussion is the presence of pesticides. As you probably know, or should know, conventional agriculture is heavily dependent on synthetic pesticides, whereas organic standards prohibit their use.
It stands to reason, then, that organic foods would expose you to lower amounts of toxic chemicals, which in and of itself can result in improved health. In fact, a key part of a healthy diet and lifestyle in general is the absence of toxic chemicals.
Last December I interviewed André Leu about his book The Myths of Safe Pesticides. If you're of the belief that pesticides are safe, and therefore of no concern when selecting foods, you may want to listen to that interview, provided above for your convenience.
Organic Diet Results in Lower Pesticide Load
Claimed to be the largest of its kind, a new study1 published in the Environmental Health Perspectives looked at the diets of nearly 4,500 people living in six US cities, assessing exposure levels to organophosphates (OPs), which are among the most commonly used insecticides on American farms.
Participants' organophosphate levels were estimated using USDA data2 on the average levels of pesticide residue found in the fruits and vegetables that each individual reported eating.
To verify the accuracy of their estimates, they compared their calculated pesticide exposures to the actual levels of pesticide metabolites (breakdown products) excreted in the urine of a subset of 720 participants.
Not surprisingly, those who ate conventionally-grown produce were found to have high concentrations of OP metabolites, whereas those who ate organic produce had significantly lower levels.
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. According to lead author Cynthia Curl:
"If you tell me what you typically eat, I can tell you how high your pesticide exposure is likely to be. The study suggests that by eating organically grown versions of those foods highest in pesticide residues, we can make a measurable difference."
The Health Hazards of Organophosphates
Organophosphate pesticides are known for their hazards to human health. Prenatal exposure, for example, has been linked to delayed brain development, reduced IQ, and attention deficits.3,4 Symptoms of exposure include weakness, headache, diarrhea, nausea, and vomiting. Long-term exposure has been linked to neurological effects, such as:5
- Confusion and disorientation
- Memory loss
- Personality changes
While overall use of organophosphates have declined over recent decades, data6 from the US Department of Agriculture (USDA) shows that OPs are still one of the most commonly used pesticides on certain crops.
According to data7 from the Centers for Disease Control and Prevention (CDC), more than 75 percent of the US population has detectable levels of OPs in their urine, and unless you're a farmer, or live near one, your diet is one of the most likely routes of exposure.
"According to the latest data10 from the US Environmental Protection Agency (EPA), more than 33 million pounds of OPs were used in the US in 2007.
Treated crops include broccoli, cantaloupe, grapes, green beans, lettuce, nectarine, oranges, pears, spinach, strawberries, tomatoes, sweet potatoes, mangoes, and onions... Washing and/or peeling will remove some residues but not necessarily all for all fruit and vegetables...
Curl says it's important to make sure you eat enough fruit and vegetables, no matter how they're grown. 'The health benefits of eating fruit and vegetables are well established,' she says. But if you want to reduce pesticide intake, her study affirms that organic produce is a logical choice."
Organics Carry Less Risk of Exposure to Both Pesticides and Antibiotic Resistant Bacteria
A Stanford University meta-analysis11 published in 2012 also found that people who eat an organic diet tend to have lower levels of toxic pesticides in their system—particularly children. Organic meats were far less likely to contain multi-drug resistant bacteria, which is yet another major health threat.
Organic rules do not permit antibiotics to be used, whereas conventional farmers routinely give their animals antibiotics to promote rapid growth. Here, the researchers reviewed 240 studies comparing organically and conventionally grown food, including 17 human studies.
According to the authors:
"...Two studies reported significantly lower urinary pesticide levels among children consuming organic versus conventional diets, but studies of biomarker and nutrient levels in serum, urine, breast milk, and semen in adults did not identify clinically meaningful differences.
The risk for contamination with detectable pesticide residues was lower among organic than conventional produce (risk difference, 30% [CI, −37% to −23%]), but differences in risk for exceeding maximum allowed limits were small.
...the risk for isolating bacteria resistant to 3 or more antibiotics was higher in conventional than in organic chicken and pork (risk difference, 33% [CI, 21% to 45%])..."
Other studies comparing organics and conventional foods have shown the reduction in toxic exposure may be even greater than what was found in the Stanford review. As previously reported by Suppversity,12 researchers at the University of Stuttgart concluded that organic produce had, on average, a 180 times lower pesticide content than conventional products.
A Number of Studies Show Organic Foods Are More Nutritious
While Stanford was unimpressed with the nutritional differences between organic and conventional foods, several studies have found noticeable differences.13 For example, the Organic Center is conducting a multi-year study on grains, comparing nutritional differences between conventional, "natural," and organically farmed grains and grain-based products.
The investigation seeks to answer questions such as: how do conventional and organic manufacturing processes impact food quality? What toxins and food additives are present in raw and finished products? And, how do milling and cooking alter nutrient composition? While not yet complete, preliminary findings show that organic grains are more nutrient-rich.14 Organically farmed tomatoes have also been shown to have significantly higher levels of flavonoids, lycopene, and vitamin C.
Most recently, a 2014 meta-analysis15,16 of 343 peer-reviewed publications concluded that the evidence indicates there are "statistically significant and meaningful differences in composition between organic and non-organic crops/crop-based foods," adding:
"Most importantly, the concentrations of a range of antioxidants such as polyphenolics were found to be substantially higher in organic crops/crop-based foods, with those of phenolic acids, flavanones, stilbenes, flavones, flavonols and anthocyanins being an estimated 19%, 69%, 28%, 26%, 50% and 51% higher, respectively. Many of these compounds have previously been linked to a reduced risk of chronic diseases, including CVD and neurodegenerative diseases and certain cancers, in dietary intervention and epidemiological studies."
They also found that organic foods contain significantly lower levels of the toxic metal cadmium, compared to conventional crops. According to the authors: "In conclusion, organic crops, on average, have higher concentrations of antioxidants, lower concentrations of cadmium (Cd) and a lower incidence of pesticide residues than the non-organic comparators across regions and production seasons." Three earlier studies showing higher nutrient levels of organic foods include the following:
- A 2010 study,17 which was partially funded by the USDA, found organic strawberries to be more nutrient-rich than non-organic strawberries.
- A behavioral study18 conducted by the Centers for Disease Control and Prevention found higher risk of ADHD in children with higher levels of organophosphates (pesticides).
- In 2009, the American Association for the Advancement of Science featured a presentation on soil health and its impact on food quality.19 Conclusion: healthy soil leads to higher levels of nutrients in crops.
Shopper's Guide to Pesticides in Produce
To protect your health, your best bet is to buy only organic fruits and vegetables, as synthetic chemicals are not permissible under the USDA organic rules. That said, not all conventionally grown fruits and vegetables are subjected to the same amount of pesticide load. 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.
To do this, I recommend familiarizing yourself with the Environmental Working Group's (EWG) annual Shoppers' Guide to Pesticides in Produce.20 Of the 48 different fruit and vegetable categories tested by the EWG for the 2014 guide, the following 15 fruits and vegetables had the highest pesticide load, making them the most important to buy or grow organically:
Apples Strawberries Grapes Celery Peaches Spinach Sweet bell peppers Nectarines Cucumbers Cherry tomatoes Imported snap peas Potatoes Hot peppers Blueberries Lettuce
In contrast, the following foods were found to have the lowest residual pesticide load, making them the safest bet among conventionally grown vegetables. Note that a small amount of sweet corn and most Hawaiian papaya, although low in pesticides, are genetically engineered (GE). If you're unsure of whether the sweet corn or papaya is GE, I'd recommend opting for organic varieties. To review the ranking of all 48 foods tested, please see the EWG's 2014 Shoppers' Guide to Pesticides in Produce:21
Avocado Sweet corn Pineapple Cabbage Frozen sweet peas Onions Asparagus Mangoes Papayas (non-GMO. Most Hawaiian papaya is GMO) Kiwi Eggplant Grapefruit Cantaloupe Cauliflower Sweet potatoes
Where to Find Healthy Food
To avoid as many pesticides as possible, focus your diet on organic foods—or those known to have lower pesticide residues despite being conventionally grown—and remember to swap out your regular meat sources to organic, grass-fed/pasture-raised versions of beef and poultry. This may be even more important than buying organic fruits and vegetables. The same goes for dairy products and animal by-products such as eggs.
One of the most compelling reasons to eat organic is to avoid toxins. Organic foods do tend to have a better nutritional profile, but even if they do not, the absence of drugs, pesticides, hormones, and antibiotics is more than enough of a reason to make the switch to protect your health. For a step-by-step guide to making healthier diet choices, please see my freely available optimized nutrition plan, starting with the beginner plan.
While many food stores carry organic foods these days, your best bet is to source it from a local grower, as much of the organic food sold in grocery stores is imported. Not only has this food traveled a long distance, adding to the carbon footprint, but some countries may have more lax organic standards than others. Buying local food also supports local farmers and promotes the establishment of a more sustainable local food system. If you reside in the US, the following organizations can help you locate farm-fresh foods in the vicinity of where you live:
Weston Price Foundation22 has local chapters in most states, and many of them are connected with buying clubs in which you can easily purchase organic foods, including grass fed raw dairy products like milk and butter. 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. Farmers' Markets -- A national listing of farmers' markets. Eat Well Guide: Wholesome Food from Healthy Animals -- The Eat Well Guide is a free online directory of sustainably raised meat, poultry, dairy, and eggs from farms, stores, restaurants, inns, and hotels, and online outlets in the United States and Canada. 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.