The most comprehensive analysis ever performed comparing organic foods with those “conventionally” grown with synthetic pesticides and fertilizers has concluded that organic fruits and vegetables are not just less toxic but actually more nutritious than conventional produce.
The difference between organic and conventional produce was so striking, the researchers said, that switching to an all-organic diet might be the nutritional equivalent of adding one or two daily servings of fruits and vegetables to your diet.
“The crucially important thing about this research is that it shatters the myth that how we farm does not affect the quality of the food we eat,” said Helen Browning, chief executive of the Soil Association, who was not involved in the study.
Yet the findings were downplayed in news reports, which quoted prominent nutritionists minimizing the nutritional differences found and ignoring the issue of pesticides completely.
The peer-reviewed study was funded by the European Union and the Sheepdrove Trust, conducted by an international research team and published in the British Journal of Nutrition. The researchers analyzed 343 prior peer-reviewed studies from around the world that had measured differences between organic and conventional fruits, vegetables and grains. It is the largest meta-analysis on the topic ever conducted.
The researchers found that there was a statistically significant difference in the nutritional content of organic and conventional produce, with organic fruits and vegetables containing between 19 percent and 69 percent more antioxidants than their conventional counterparts.
Although no studies have yet been conducted to compare the long-term health differences between those who follow mostly organic versus mostly conventional diets, the researchers note that antioxidants such as those found in higher concentrations in organic foods “have previously been linked to a reduced risk of chronic diseases, including cardiovascular diseases, neurodegenerative diseases and certain cancers.”
The higher antioxidant levels found are equivalent to the amount in “one to two of the five portions of fruits and vegetables recommended to be consumed daily,” the researchers wrote, “and would therefore be significant and meaningful in terms of human nutrition, if information linking these [compounds] to the health benefits associated with increased fruit, vegetable and whole grain consumption is confirmed.”
In addition to the nutritional benefits, the researchers also found that conventional produce and grains were four times more likely to contain pesticide residues than their organic counterparts, and also contained significantly higher concentrations of the toxic heavy metal cadmium. These differences were also statistically significant.
“This study demonstrates that choosing food produced according to organic standards can lead to increased intake of nutritionally desirable antioxidants and reduced exposure to toxic heavy metals,” said lead author Carlo Leifert of Newcastle University. “This constitutes an important addition to the information currently available to consumers which until now has been confusing and in many cases is conflicting.”
Short-sighted nutritionists fight back
Media reports have largely portrayed the study’s findings as controversial and have quoted nutritionists skeptical of the results. The study’s critics have mostly focused on casting doubt on the health benefits of antioxidants, or expressing concern that encouraging people to eat more organic foods would (due to the cost difference) cause them to eat less fruits and vegetables overall.
“Ultimately we all need to eat more fruit and vegetables regardless of whether they are organic or not to form part of a healthy balanced diet, which will help protect health,” said Dr. Alison Tedstone, Chief Nutritionist at Public Health England.
By and large, these critics have ignored the findings that organic foods were also lower in pesticides and heavy metals, even though many pesticides are known to accumulate in the human body and cause serious health problems at even very low concentrations.
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