The Argument for Organic Food Lies Beyond the Nutrients

The effects of pesticides
By Karen Congro, RD, CDN

Many people were shocked recently when a study in the September 4 issue of the Annals of Internal Medicine found little difference in the nutritional value of organic and conventional foods. While these conclusions were surprising and elicited headlines around the nation, the study pointed to another compelling reason to eat organic foods.

The authors’ review made the case that, though some organic foods have greater concentrations of vitamin C and proteins, there is no strong evidence that organic foods are always more nutritious or carry fewer health risks than conventional foods—but the authors did note that people who eat organic foods can reduce their risk of pesticide exposure.

If you listen to the message of doctors of environmental medicine such as William Rea, MD, and Andrew Campbell, MD, there is strong evidence that limiting the consumption of pesticides and chemical fertilizers, neurotoxins, hormone disruptors, developmental and reproductive toxins, and antibiotics found in conventionally grown produce may play a role in reducing risks for a variety of diseases, especially cancer.

But there are other areas of concern as well. When scientists looked at children who ate organic food versus those who ate conventional food, the second group had higher residues of pesticides in their urine. This finding is alarming because it indicates that pesticide consumption could have a cumulative effect.

Whether pesticide consumption is cumulative is just one of many questions we are unable to answer. How do pesticides accumulate in our system? How are they stored over our lifetime? What role does a person’s weight or age play in this process?

There are still no comprehensive, long-term studies on organic farming. Although government agencies have recommended what they consider “safe” levels of pesticides in fruits or vegetables, no one has been able to calculate the health risks over time. Eventually we will know more about the best organic growing methods to yield nutritionally superior and safer produce, but until that time there are some steps that can be taken for people who want to follow a healthy diet.

Dealing with pesticides

Regardless of whether or not produce is organic, it is very important to always wash fruits and vegetables to remove bacteria such as listeria, salmonella, and E. coli. Contamination occurs during harvesting, storage in warehouses, and handling in grocery stores.

While washing will probably remove surface pesticide residue, fruits such as peaches, plums, strawberries, and other berries absorb pesticides through their skin. There are special “detergents” available to clean fruits and vegetables, but some experts believe that these agents pose their own problems.

For the safest options, the Environmental Working Group’s (EWG) list of the “Dirty Dozen” (apples, peaches, bell peppers, celery, nectarines, strawberries, cherries, kale, blueberries, grapes, potatoes, and spinach) and the “Clean 15” (watermelon, pineapple, mangoes, onions, avocados, sweet corn, asparagus, sweet peas, kiwis, cabbage, eggplant, papayas, broccoli, tomatoes, and sweet potatoes) is an excellent guide to pesticides in produce. In the case of the Clean 15, it is not necessary to buy organic. But even with the Dirty Dozen, EWG says the benefit of eating fresh fruits and vegetables outweighs the known risks of consuming pesticide residue. However, consider some of the biggest offenders:

>> Celery is treated with up to 64 different pesticides. Every stalk has traces of chlorantraniliprole, which kills caterpillars, moths, and beetles by over-stimulating their muscles to contract.

>> Chilean grapes have 34 different pesticides.

>> Blueberries are sprayed with 52 pesticides, including boscalid and pyraclostrobin, which are toxic to the human liver and thyroid and can irritate the skin in high doses.

>> Sweet peppers have tested positive for 50 pesticide residues, including 25 suspected hormone disruptors.

>> Strawberries, which act like sponges to absorb six carcinogens and 13 hormone disruptors, are especially problematic because they are so difficult to clean.

>> Pears have been found to have residue from over two dozen pesticides, including six carcinogens, 13 suspected hormone disruptors, eight neurotoxins, and four reproductive or developmental toxins.

>> Apples are some of the most pesticide laden of non-organically-grown produce, with samples from around the United States containing over 40 different pesticide residues. Nine out of every 10 apples have traces of the fungicide thiabendazole, a known carcinogen. Eight have diphenylamine, which is linked to bladder tumors. Workers who apply this pesticide need to wear long sleeves and gloves. Apples carry 40 other pesticides, including carcinogens, hormone disrupters, neurotoxins, and developmental toxins.

Should we give up apples?

People who don’t have access to organic apples, pears, and peaches may be better off peeling these fruits to remove most of the pesticide residue. The majority of my patients are from low-income populations, so the grocery budgets are tight. Those who shop in supermarkets are often lucky to get edible fruits and produce. Many have vouchers that they can use at green markets and farmers’ markets, which generally carry organic foods. However, the prices at these markets can sometimes be prohibitive. In the case of patients who are eating several apples a day—an excellent low-calorie food perfect for weight loss—I suggest they comparison shop and stock up on organic apples whenever and wherever they go on sale, since apples keep especially well in the refrigerator crisper, especially when stored in perforated plastic bags.

Other non-organic produce can also benefit from removing the outer layers. For example, remove the outer leaves of spinach—which has the neurotoxins imidacloprid and permethrin, along with many other pesticides—before washing with warm water mixed with salt, and either lemon juice or vinegar. Berries, including strawberries, should be rinsed thoroughly and drained in a colander.

How bad are pesticides?

The use of imidacloprid, one of the most widely used pesticides, is a cautionary tale.

Imidacloprid is a neurotoxin that is sprayed on the vast majority of corn crops and genetically altered corn seed. It makes its way from the germinating seed to the growing seed and into the corn kernel. A study in the Bulletin of Insectology on colony collapse disorder (CCD) showed the devastating effects from imidacloprid found in high fructose corn syrup (HFCS) fed to bees.

Beekeeping has changed little over time, except for the use of HFCS as a winter food for bees instead of honey. HFCS is made from sugars extracted from corn kernels. Scientists are studying whether the use of imidacloprid is playing a role in the current bee die-off.

We’re also seeing changes in people that could be a side effect of what we’re doing to our foods. Some scientists believe that pesticides are linked to endocrine disorders in young children, ADHD, and autism. Antibiotic resistance is a growing health issue and may be linked to the use of antibiotics in beef, poultry, and milk, while the use of hormones in milk may be linked to early-onset puberty.

The use of pesticides, hormones, and antibiotics may also have deleterious effects on other segments of the population, such as people with poor immune systems and elderly people, who have more difficulty eliminating toxins from the liver.

In the Stanford University meta-analysis published in the Annals of Internal Medicine, Crystal Smith-Spangler, MD, and her colleagues spent four years looking at data from 237 studies examining a wide variety of fruits, vegetables, and meats. The study found that organic chicken and pork were 33 percent less likely to carry bacteria resistant to multiple antibiotics than conventionally produced meat. In addition, the study showed that organic milk and chicken may contain more omega-3 fatty acids, which are considered beneficial for the heart.

While standards for organics have improved, the organic movement is still in its early stages. The USDA now requires certification for organic farmers with guidelines for everything from the use of organic substances to beneficial insects. There are still pressing questions, however. Are trace pesticides present in soil, and how long does it take to get rid of them? Can that process be accelerated? When there is runoff, what happens to the pesticides that go into the environment?

As the controversy between organic versus conventionally grown produce continues, the good news is that organic food is becoming more widely available, everywhere from backyard gardens to urban rooftop farms which primarily use organic growing methods.

Organic food may not always contain more nutrients than conventional food—it’s what they don’t contain that puts them at a premium.


Karen Congro, RD, CDN, is the founder of the Wellness for Life program at the Brooklyn Hospital Center. Wellness for Life is a free monthly education program designed to help patients make the healthiest lifestyle choices possible.


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