(Beyond Pesticides, August 3, 2009) Sometimes you have to look a little deeper to find the truth, as is the case with the headlines over the past week regarding organic produce’s nutritional value. Last week the London School of Hygiene & Tropical Medicine (LSHTM) researchers announced the publication of their new study, “Nutritional quality of organic foods: a systematic review,” to be published in the September issue of The American Journal of Clinical Nutrition, which finds “no evidence that organically produced foods are nutritionally superior to conventionally produced foodstuffs.” Organic advocates and consumers say the study and the press announcement fail at providing all the facts and are misleading in guiding people away from all the benefits organic products provide.
“Unfortunately, it failed to include contemporary research showing organic strengths, and dismisses areas of organic superiority within its reviewed work, including antioxidant capacity (important for cancer-fighting properties),” states Timothy LaSalle, CEO of the Rodale Institute in the Huffington Post. “The study appears to say absolutely nothing negative about organics, despite valiant attempts by the media to create sensational headlines.”
Over 50,000 papers were searched, and a total of 162 relevant articles were identified that were published over a fifty-year period up to February 29, 2008 and compared the nutrient content of organically and conventionally produced foodstuffs. A total of 55 of the identified papers were of satisfactory quality, and analysis was conducted comparing the content in organically and conventionally produced foods of the 13 most commonly reported nutrient categories. The review was commissioned by the UK Food Standards Agency (FSA).
“The review rejected almost all of the existing studies of comparisons between organic and non-organic nutritional differences. This was because these studies did not meet particular criteria fixed by the London School of Hygiene and Tropical Medicine, which carried out the review,” said Peter Melchett, policy director at the Soil Association, in a response to the study findings. “There are limited studies available on the health benefits of organic versus non-organic food. Without large-scale, longitudinal research it is difficult to come to far-reaching clear conclusions on this, which was acknowledged by the authors of the FSA review.”
The press statement released by LSHTM states, “The researchers found organically and conventionally produced foods to be comparable in their nutrient content. For 10 out of the 13 nutrient categories analyzed, there were no significant differences between production methods in nutrient content. Differences that were detected were most likely to be due to differences in fertilizer use (nitrogen, phosphorus), and ripeness at harvest (acidity), and it is unlikely that consuming these nutrients at the levels reported in organic foods would provide any health benefit.”
“Although the researchers say that the differences between organic and non-organic food are not ‘important’, due to the relatively few studies, they report in their analysis that there are higher levels of beneficial nutrients in organic compared to non-organic foods,” responds Mr. Melchett. “For example, the mean positive difference between the following nutrients, when comparing organic to non-organic food, was found in the FSA study to be: protein 12.7%; beta-carotene 53.6%; flavonoids 38.4%; copper 8.3%; magnesium 7.1%; phosphorous 6%; potassium 2.5%; sodium 8.7%; sulphur 10.5%; zinc 11.3%; and, phenolic compounds 13.2%. The researchers also found higher levels of beneficial polyunsaturated fatty acids in organic meat and dairy products (between 2.1% – 27.8% higher) compared to non-organic meat and dairy.”
The FSA study also failed to include the results of a major European Union-funded study involving 31 research and university institutes and the publication, so far, of more than 100 scientific papers, which ended in April this year. According to the Soil Association, the European Union research program concluded that:
”¢ Levels of a range of nutritionally desirable compounds (e.g. antioxidants, vitamins, glycosinolates) were shown to be higher in organic crops;
”¢ Levels of nutritionally undesirable compounds (e.g. mycotoxins, glycoalkaloids, Cadmium and Nickel) were shown to be lower in organic crops; and,
”¢ Levels of fatty acids, such as CLA and omega 3 were between 10 – 60% higher in organic milk and dairy products, and levels of Vitamin C were up to 90% higher in leafy vegetables and fruits.
A response by The Organic Center (TOC) states that the study, “also ignored the 15 relevant studies that have come out since their February 2008 cut off date that could have changed the outcome of the report. In addition, the FSA analysis actually found that organic food contains more phosphorus, a beneficial nutrient, while conventional food on average contains more nitrogen, which scientists have linked to cancer ”¦ Despite the fact that [the] three categories of nutrients favored organic foods, and none favored conventionally grown foods, the London-based team concluded that there are no nutritional differences between organically and conventionally grown crops.” TOC also argues that the researchers “used data from very old studies assessing nutrient levels in plant varieties that are no longer on the market.”
Another failure of the study is that it did not include a review of the content of contaminants or chemical residues in foods, which makes organic products superior in quality. This past spring, TOC released a new study on how a balanced, organic diet – both before and during pregnancy – can significantly reduce a child’s likelihood of being overweight, obese or developing diabetes, based on a literature review of over 150 scientific studies. The TOC review finds that exposure to pesticides during pregnancy increases the risk of premature birth, low-birth weight, neurological problems and diabetes. Outlining six ways in which a balanced organic diet can contribute to healthy development, the report also examines how enzymes found in organic foods can slow and even reverse aspects of the aging process.
In 2008, a comprehensive review of 97 published studies comparing the nutritional quality of organic and conventional foods shows that organic plant-based foods (fruits, vegetables, grains) contain higher levels of eight of 11 nutrients studied, including significantly greater concentrations of the health-promoting polyphenols and antioxidants. The team of scientists from the University of Florida and Washington State University concludes that organically grown plant-based foods are 25% more nutrient dense, on average, and hence deliver more essential nutrients per serving or calorie consumed. The findings are published in TOC report, “New Evidence Confirms the Nutritional Superiority of Plant-based Organic Foods.” In response to the FSA study, TOC has published a comparison between the two studies, click here.
Consumers purchase organic products because organic farming and food systems are holistic, are produced to work with nature rather than to rely on inputs such as chemical pesticides and fertilizers, have higher standards for the welfare of animals, and do not allow routine use of antibiotics. Organic farming also protects the farmworkers and their families from chemicals that have been shown to cause a myriad of chronic health effects, such as cancer, endocrine disruption and a series of degenerative diseases like Parkinson’s disease.
For more information of the many benefits of organic food, please visit Beyond Pesticides’ Organic Food program page.