Nutritional Considerations - Organic Trade Association

Benefit of organic

Growing crops in healthy soils results in food products that offer healthy nutrients.

There is mounting evidence that organically grown fruits, vegetables and grains may offer more of some nutrients, including vitamin C, iron, magnesium and phosphorus, and less exposure to nitrates and pesticide residues than their counterparts grown using synthetic pesticides and fertilizers.

At the 2005 international congress Organic Farming, Food Quality and Human Health, Professor Carlo Leifert of Newcastle University reported findings that organically produced food had higher level of specific antioxidants and lower mycotoxin levels than conventional samples, and that grass-based organic cattle diets reduce the risk of E. coli contamination while grain-based conventional diets increase the risk. See http://www.qlif.org/ about the congress.
Rats fed organic food were slimmer, slept better, and had stronger immune systems than those fed conventionally grown produce, according to a team of scientists from the Danish Institute of Agricultural Sciences and a Newcastle University scientist. Dr. Kirsten Brandt of Newcastle University's School of Agriculture helped devise the experiment, with findings reported in the Feb. 18, 2005, issue of The Scotsman.
Reviewing 41 published studies comparing the nutritional value of organically grown and conventionally grown fruits, vegetables, and grains, certified nutrition specialist Virginia Worthington has concluded there are significantly more of several nutrients in organic crops. These include: 27% more vitamin C, 21.1% more iron, 29.3% more magnesium, and 13.6% more phosphorus. In addition, organic products had 15.1% less nitrates than their conventional counterparts. She also noted that five servings of organic vegetables (lettuce, spinach, carrots, potatoes and cabbage) provided the recommended daily intake of vitamin C for men and women, while their conventional counterparts did not. Worthington said the results are consistent with known soil dynamics and plant physiology.
Source: "Nutritional Quality of Organic Versus Conventional Fruits, Vegetables, and Grains," by Virginia Worthington, published in The Journal of Alternative and Complementary Medicine, Vol. 7, No. 2, 2001 (pp. 161-173), available at: www.foodisyourbestmedicine.com/organic.pdf. Worthington has her Masters of Science in Nutritional Sciences from the University of Maryland, and Doctor of Science from Johns Hopkins University School of Public Health.
Organic crops appear to be higher in vitamin C, essential minerals and phytonutrients, according to the 87-page report prepared for The Soil Association of the United Kingdom and released during 2001. Reviewing 400 published papers comparing organic and non-organic foods concerning food safety, nutritional content and observed health effects, the report noted the need for further studies.
Source: "Organic Farming, Food Quality and Human Health: A review of the evidence," written and researched by Shane Heaton, The Soil Association, United Kingdom, 2001.
An Italian study has found organic pears, peaches and oranges had higher antioxidant levels than their conventional counterparts. The study, which began three years and is still ongoing, is being conducted by the Istituto nazionale di ricerca per gli alimenti e la nutrizione (National Institute of Food and Nutrition Research). In particular, researchers found that organic William's pears contain less fiber but more natural sugar, vitamin C and antioxidants compared to their conventional counterparts, and were more resistant to mildew and fungi. Organic Regina Bianca peaches, meanwhile, contain more antioxidants.
Source: The Organic Newsline from organicTS.com, Vol. 3, Issue 3, September 2002.
A study commissioned by the Organic Retailers and Growers Association of Australia (ORGAA) found that conventionally grown fruit and vegetables purchased in supermarkets and other commercial retail outlets had ten times less mineral content than fruit and vegetables grown organically. For the study, tomatoes, beans, capsicums and silver beets grown on a certified organic farm using soil regenerative techniques were analyzed for mineral elements. A similar range of vegetables grown conventionally and purchased from a supermarket was also analyzed by the Australian Government Analytical Laboratory. A major flaw of the study, however, is that it compared fresh produce at the farm to produce in a supermarket. Thus, there could have been a difference in freshness, which could have affected the nutrients measured.
Source: Organic Retailers and Growers Association of Australia, 2000, as cited in Pesticides and You, Vol. 20, No. 1, Spring 2000, News from Beyond Pesticides/National Coalition Against the Misuse of Pesticides.
A comparative study conducted by researchers at the Research Institute of Organic Agriculture (FiBL) in Switzerland found that organically grown apples were of higher quality than conventionally grown apples with respect to parameters that relate to health and taste (taste score, sugar-acidity-firmness index, nutritional fiber content, phenolic compounds content, and "vitality index" according to picture-grading methods for holistic quality assessment).
Source: "Are organically grown apples tastier and healthier? A comparative field study using conventional and alternative methods to measure fruit quality," F.P. Weibel, R. Bickel, S. Leuthold, and T. Alföldi), Acta Hort. 517: 417-427 (2000).
A study has shown that organic soups sold commercially in the United Kingdom contain almost six times as much salicylic acid as non-organic soups. John Paterson, a biochemist at Dumfries and Galloway Royal Infirmary, and scientists at the University of Strathclyde in Scotland analyzed 11 brands of organic soup and compared their levels of salicylic acid with those in non-organic varieties. Salicylic acid, which is responsible for the anti-inflammatory action of aspirin, has been shown to help prevent hardening of the arteries and bowel cancer. The average level of salicylic acid in 11 brands of organic vegetable soup was 117 nanograms per gram, compared with 20 nanograms per gram in 24 types of non-organic soup. The highest level (1,040 nanograms per gram) was found in an organic carrot and coriander soup. Four of the conventional soups had no detectable levels of salicylic acid. [Source: New Scientist magazine, March 16, 2002, page 10; European Journal of Nutrition, Vol, 40, page 289].
Research by visiting chemistry professor Theo Clark and undergraduate students at Truman State University in Missouri found organically grown oranges contained up to 30 percent more vitamin C than those grown conventionally. Reporting the findings at the June 2 Great Lakes Regional meeting of the American Chemical Society, Clark said he had expected the conventional oranges, which were much larger than the organic oranges, to have twice as much vitamin C as the organic versions. Instead, chemical isolation combined with nuclear magnetic resonance spectroscopy revealed the higher level in the organic oranges.
[Source: Science Daily Magazine, June 2, 2002.]
Findings from a Danish study published in the Journal of Agricultural and Food Chemistry (Vol. 51, No. 19, 2003, pp. 5671-5676) showed organic vegetables have a higher concentration of natural antioxidants called flavonoids. The double-blind randomized, crossover study had two intervention periods, with test participants given organic food or conventional food for three weeks. Results were based on blood and urine samples tested. The study was conducted by The Institute of Food Safety and Nutrition under The Danish Veterinary and Food Administration, The Department of Human Nutrition and Centre for Advanced Food Studies under The Royal Veterinary and Agricultural University, and Risø National Laboratory.
Argentine researchers have found that organic Swiss chard compares well with conventional chard in storage both for microbial and sensorial quality as well as storage life. Source: M. del R. Moreira, S.I. Roura, and C.E. Del Valle, "Quality of Swiss chard produced by conventional and organic methods," Lebensmittel-Wissenschaft und-Technolgie 36(1) 2003, pages 135-141.
Findings released in 2003 from studies at the Danish Institute of Agricultural Sciences suggest that organic milk is higher in conjugated linoleic acids (CLA) than conventional milk. The studies also showed that feeding clover to dairy cows led to increased levels of CLA in the milk. (Source: http://www.organicts.com/). Previous research at the University of Wisconsin at Madison found that dairy cattle that graze produce higher amounts of CLA in their milk than those eating grain, hay and silage. In animal studies, CLA has been linked to preventing cancer in rats and atherosclerosis in rabbits.
Organic fruits and vegetables show significantly higher levels of antioxidants than their conventionally grown counterparts, according to findings published by researchers at the University of California at Davis. In the study, researchers led by food scientist Alyson Mitchell compared the antioxidant levels in corn, strawberries and marionberries grown organically, sustainably (using fertilizer but no herbicides or pesticides) and conventionally. Antioxidant levels in sustainably grown corn were 58.5 percent higher than conventionally grown corn, while organically and sustainably grown marionberries had approximately 50 percent more antioxidants than conventionally grown berries. Sustainably and organically grown strawberries had about 19 percent more antioxidants than their conventional counterparts. The findings were published in the Feb. 26, 2003, print edition of the American Chemical Society peer-reviewed Journal of Agricultural and Food Chemistry. The study also showed sustainably grown and organic produce had more ascorbic acid, which the body converts to vitamin C. Source: "Comparison of the Total Phenolic and Ascorbic Content of Freeze-Dried and Air-Dried Marionberry, Strawberry, and Corn Grown Using Conventional, Organic, and Sustainable Agricultural Practices," D.K. Asami, Y.-J. Hong, D.M. Barrett, and A.E. Mitchell, Journal of Agricultural and Food Chemistry, 51(5):1,237-1,241 (2003).

Meanwhile:

Reporting on its study examining pesticide residues in foods bought around the country, Consumer Reports, January 1998, noted: "Our side-by-side tests of organic, green-labeled, and conventional unlabeled produce found that organic foods had consistently minimal or nonexistent pesticide residue."
Source: "Greener Greens? The Truth about Organic Foods," Consumer Reports, January 1998, page 13.
Analyzing U.S. Department of Agriculture's Pesticide Data Program data comparing the relative amounts and toxicity of pesticide residues in different foods, a Consumer Union report found that fresh peaches, frozen and fresh winter squash, apples, grapes, spinach, pears, and green beans had some of the highest Toxicity Index ratings. As a result, the Consumers Union recommended purchasing organically grown apples, peaches, pears, grapes, winter squash, spinach and green beans.
Source: "Do you know what you're eating? An analysis of U.S. Government Data on Pesticide Residues in Foods," February 1999, Consumers Union of United States Inc., Edward Groth III, project director.
Organic fruits and vegetables have only a third as many pesticide residues as their conventionally grown counterparts, according to a study by Consumers Union (CU) and the Organic Materials Review Institute. Study findings are based on pesticide residue data collected by the U.S. Department of Agriculture, from tests conducted on foods sold in California by the California Department of Pesticide Regulation, and from tests by Consumers Union. Data covered more than 94,000 food samples from more than 20 crops, with 1,291 of the samples organically grown. USDA data showed 73 percent of conventionally grown foods sampled had residue from at least one pesticide, while only 23 percent of organically grown samples of the same crops had any residues. When residues of persistent, long-banned organochlorine insecticides such as DDT were excluded from the analysis, organic samples with residues dropped from 23 to 13 percent. More than 90 percent of USDA's samples of conventionally grown apples, peaches, pears, strawberries and celery had residues. The California data found residues in 31 percent of the conventional food, and 6.5 percent of the organic products. Tests by the Consumers Union, meanwhile, found residues on 79 percent of conventionally grown samples and 27 percent on the organic products. Source: Food Additives and Contaminants, May 8, 2002. Also, see http://www.omri.org/.
Data from the Associazione Italiana per l'Agricoltura Biologica and Legambiente show consumers in Italy consume approximately two kilos of chemicals and pesticides from products grown through conventional farming practices. In 2000, 30 percent of vegetables and 40 percent of fruit in more than 5,000 fruit and vegetable samples in Italy showed evidence of pesticide residues. Source: Associazione Italiana per l'Agricoltura Biologica and Legambiente, Oct. 2, 2001, as cited in OrganicTS.com, Oct. 5, 2001.
In 2003, The Environmental Working Group (EWG) and Stonyfield Farm collaborated to produce a "Shopper's Guide to Pesticides in Produce" using EWG findings on pesticides on produce. For the guide, EWG researchers analyzed over 100,000 U.S. government pesticide test results and found 192 different pesticides on 46 popular fresh fruits and vegetables. Using this information, Stonyfield has created the wallet-size guide for consumers to use. The guide, downloadable from http://www.foodnews.org/walletguide.php, lists the 12 produce items that are highest in pesticide residues, and the 12 with the lowest levels. The highest, listed in alphabetical order, are apples, bell peppers, celery, cherries, grapes (imported), nectarines, peaches, pears, potatoes, red raspberries, spinach, and strawberries. The ones with the lowest pesticide residue levels (in alphabetical order) are: asparagus, avocados, bananas, broccoli, cauliflower, corn (sweet), kiwi, mangos, onions, papaya, pineapple, and peas (sweet). A detailed description of the criteria used in developing the rankings and a full list of the produce tested, is available at http://www.foodnews.org/.
A study published in the March 2003 issue of the peer-reviewed journal Environmental Health Perspectives showed that consuming organic products may lower children's exposure to potentially damaging pesticides. In the study, researchers at the School of Public Health and Community Medicine, University of Washington, recruited families at both a retail chain grocery store selling primarily conventional foods and at a local cooperative selling a large variety of organic foods in the Seattle, WA, metropolitan area. Parents were asked to keep a food diary for their children for three days, then the children's urine collected on day three was analyzed for pesticide metabolites. Children eating primarily organic diets had significantly lower levels organophosphorus (OP) pesticide metabolite concentrations than did children eating conventional diets. In fact, concentrations of dimethyl metabolites, one OP metabolite group, were approximately six times higher for the children eating conventional diets. Other studies indicate that chronic low-level exposure to OP pesticide may affect neurological functioning, neurodevelopment, and growth in children. "Dose estimates suggest that consumption of organic fruits, vegetables, and juice can reduce children's exposure levels from above to below the U.S. Environmental Protection Agency's current guidelines, thereby shifting exposures from a range of uncertain risk to a range of negligible risk," authors Cynthia L. Curl, Richard A. Fenske, and Kai Elgethun wrote, adding, "Consumption of organic produce appears to provide a relatively simple way for parents to reduce their children's exposure to OP pesticides." A previous study by members of the study team had shown that children eating primarily organic diets had significantly lower OP pesticide exposure than did children consuming primarily conventional diets. In fact, an earlier study found no measurable pesticide metabolites in the urine of a child whose family bought exclusively organic produce. [Original study: Environmental Health Perspectives, Vol. 109, No. 3, March 2001 (pp. 299-303, C. Lu, D.E. Knutson, J. Fisker-Andersen, and R.A. Fenske, "Biological Monitoring Survey of Organophosphorus Pesticide Exposure among Preschool Children in the Seattle Metropolitan area"). Subsequent study: Environmental Health Perspectives ehponline.org, posted online Oct. 31, 2002, C.L. Curl, R.A. Fenske, and K. Elgethun, "Organophosphorus pesticide exposure of urban and suburban pre-school children with organic and conventional diets."].