Fuhrman: Should we only buy organic produce?
VALLEY — There is not a definite “yes” or “no” answer to this question. There may be important time periods at which people are more vulnerable to the potential harm of pesticide residues on our food: just prior to conception, during pregnancy, and during early childhood. There is evidence that organophosphate pesticide exposure during these time periods is associated with deficits in cognitive and behavioral development in children.
There are some clear environmental benefits to buying organic produce. However, it is unclear whether there are health risks to consumers from ingesting pesticides from conventional produce. Each year the Environmental Working Group (EWG) releases their “Dirty Dozen” and “Clean Fifteen” lists. Using pesticide residue data from the USDA, the EWG ranks the highest and lowest pesticide fruits and vegetables.
The 2017 Dirty Dozen list contains strawberries, spinach, nectarines, apples, peaches, pears, cherries, grapes, celery, tomatoes, sweet bell peppers, and potatoes. The 2017 Clean Fifteen list contains sweet corn, avocados, pineapples, cabbage, onions, sweet peas, papayas, asparagus, mangoes, eggplant, honeydew, kiwi, cantaloupe, cauliflower, and grapefruit. EWG recommends buying the organic versions of the fruits and vegetables on the Dirty Dozen list to minimize exposure to synthetic pesticides.
Organic agriculture utilizes crop rotation, compost and manure as fertilizers, soil and water conservation practices, natural methods for managing pests, and no synthetic pesticides. Some of the goals of organic agriculture, according to the USDA’s organic program, are to promote ecological balance and conserve biodiversity.
Pesticide exposure: The Environmental Protection Agency sets limits for safe consumption of pesticides; they estimate an exposure level called the chronic reference dose, the amount of a chemical a person could be exposed to daily throughout life without any harmful effects. A 2011 study estimated typical amounts of exposure to synthetic pesticides based on the USDA’s pesticide residue data for fruits and vegetables on the Dirty Dozen list. They found that most pesticides were present at amounts one thousand times smaller than the chronic reference dose. Even the highest pesticide residue detected was only 2 percent of the chronic reference dose. This puts the Dirty Dozen list in perspective: it means that even the highest pesticide conventional produce is very low in pesticides.
Is that small amount of synthetic pesticide any risk to consumers? Some scientists think that pesticide residues do not pose health risks, because humans and other animals are exposed to small amounts of naturally occurring toxins in every plant food we eat. The body regularly breaks down self-produced metabolic wastes and naturally occurring carcinogens in foods, as well as pesticides, and excretes these harmful substances.
Greater concentrations of urinary breakdown products of synthetic pesticides have been found in frequent consumers of conventional produce compared to frequent consumers of organic produce, and several short-term studies have shown that switching conventional foods for organic foods reduces urinary pesticide metabolites. However, evidence is lacking whether the consumer gains any significant health benefit by eating organic instead of conventional produce.
What about people who work with pesticides in agriculture? Studies suggest a link between pesticide exposure and brain cancer, Parkinson’s disease, multiple myeloma, leukemia, lymphoma, and cancers of the stomach and prostate. A study comparing several markers of DNA damage in blood samples of conventional and organic farmers found evidence of greater DNA damage in conventional farmers. This suggests supporting organic agriculture can help to reduce the harmful effects of synthetic pesticide exposure for those who work in agriculture and are exposed to very high doses.
There are environmental advantages. Organic agriculture avoids conventional fertilizers, aiming to prevent harmful nitrogen runoff into waterways. Avoiding synthetic pesticides prevents pesticide contamination of groundwater. Although organic pest management methods may not work as well as conventional in some cases, there is a great deal of evidence that organic crops bring better soil quality, less soil erosion, more plant diversity, and more diversity in insects, soil organisms, and birds.
Regarding nutritional differences, there appears to be a small increase in antioxidant content in organic fruits and vegetables compared to their conventional counterparts.
There is growing evidence that exposure to a mixture of synthetic pesticides is harmful to the bees we depend on as pollinators for many crops. A shift toward organic agriculture could help to alleviate some of the stress on bee populations.
Note that the “Dirty Dozen” are not our major dietary source of exposure to harmful chemicals. Exposure to persistent organic pollutants such as organochlorine pesticides and PCBs occurs primarily via fatty animal foods like fish, dairy products, and meat. Also, glyphosate, an herbicide linked to non-Hodgkin lymphoma in agricultural workers, is present primarily in processed foods.
By centering your diet on unrefined plant foods, you will automatically reduce your exposure to potentially dangerous chemicals. The large volume of studies performed on typical, pesticide-treated produce has demonstrated that consumption of produce, whether organic or not, protects against chronic diseases. For your health, consuming a diet of vegetables, beans, fruit, nuts, and seeds is the most important action you can take. If you are able to buy organic vegetables and fruits, that is preferable, especially for our children, the environment and for farmers.
Dr. Fuhrman is a #1 New York Times best-selling author and a board certified family physician specializing in lifestyle and nutritional medicine. The Eat To Live Cookbook offers over 200 unique disease-fighting delicious recipes and his newest book, The End of Heart Disease, offers a detailed plan to prevent and reverse heart disease using a nutrient-dense, plant-rich eating style. Visit his informative website at DrFuhrman.com. Submit your questions and comments about this column directly to [email protected]