EVEN AS CONSUMERS PURCHASE INCREASING AMOUNTS of biologically grown organic food each year, corporate nonorganic farming interests continue to insist that there is no nutritional difference between organic and nonorganic plant foods.
Beyond the issue of spraying crops with insecticides, fungicides, and herbicides, known disease causers, nutrient-depleted soil adds another dimension to the problem we face. Over the last century, agricultural experts reported that crop growers had farmed and eroded away at least 75 percent of the nutrients in our soil. This, in turn, strongly reflects how much nutrition will be contained in plants grown and sold to consumers.
With this said, there is accumulating scientific data portraying non-sprayed organic fruits and vegetables, generally grown in nutrient-replenished soil, to be far superior nutrient sources than chemically saturated, commercially grown varieties harvested from virtual wastelands. one of the more significant studies, done in 2007, compared the flavonoid content of organic versus nonorganic tomatoes over a ten-year period. The study demonstrated that organic soils, over time, cumulatively intensify the levels of flavonoids in tomatoes, whereas nonorganic soils produced no such beneficial effect.
The finding that organic soils intensify nutrient levels over time has not been taken into account fully in many subsequent studies. This is especially true with meta-analyses or comparative reviews of studies that purport to examine the differences between organic and nonorganic growing practices. This nutrient difference ultimately shows up in products on grocery store shelves. A ground-breaking study in 1993, for instance, compared the mineral content of five food crops grown organically and conventionally as they were taken from store shelves over a two-year period. Clear gaps in nutrient levels were discovered.
Not long ago, I delved into this important subject by reading, speaking to, and interviewing the world’s leading experts on sustainable farming. Those interactions left me even more convinced that organic food, properly grown, builds healthy people.
Eating organic means limiting the levels of synthetic chemicals being absorbed, and so can contribute to a range of health benefits, which i have seen firsthand. Take Rick Metz, for instance, who had been diagnosed with clinical depression. He spent years taking antidepressants and ended up becoming addicted to them.
As Rick told me, “I finally decided to take it upon myself to find the cause of this ‘chemical imbalance’ instead of simply treating it. After research I found that the chemicals going into my body in my food, as well as personal hygiene products, needed to be examined thoroughly. I gave up all of these products and went organic and vegetarian. While I had some severe withdrawals—incessant itching—the result was far beyond my wildest dreams. I am so happy to be free of medications and to live again without depression.”
Michael Lanning is a Vietnam War veteran who embraced a raw organic vegetarian diet after being told in 2006 that he had kidney cancer, which had metastasized to the adrenal and lymph glands and his lungs. He was given only a year or less to live because neither chemotherapy or radiation would help. Resigned to dying, he e-mailed his good-byes to people he loved and respected.
Michael’s former battalion commander, a retired major general, convinced him to try a dietary approach to treatment, as a last resort. The recommended diet was raw, organic, and vegan, and consisted mostly of sprouts, greens, onions, wheatgrass and green juices.
Michael picks up his story here: “After the first week i began to detox as more and more dark spots appeared on my body, some with small pus-filled sores. My body was now consuming only good things and was ridding itself of the previous chemical poisons I had taken in. Itching accompanied the detox. I was paying for my past dietary transgressions.”
Three months after adopting this diet, Michael went to Houston’s MD Anderson Cancer Center for testing. No growth in the tumors was detected. Another year passed and the tumors remained stable. Now, several years past the date when cancer specialists predicted he would be dead, Michael remains not only alive, but vigorously so. “Since my adoption of the raw diet, I have resumed a normal life. I feel better than I did before my diagnosis. Every day that I live is one more day that seven conventional doctors said that I would not. More importantly, my days are as good as they can get.”
While eating organic in and of itself can’t explain these medical breakthroughs, the purity of the nutrients we absorb are important factors in the synergies that are created, which are a key to health. Simply said, healthy soil equals healthy plants, and that translates into healthy people. Here are the studies, presented in chronological order, lending support to that point of view.
Characterization of phenolic content, in vitro biological activity, and pesticide loads of extracts from white grape skins from organic and conventional cultivars. Corrales M, Fernandez A, Vizoso Pinto MG, et al. Food Chem Toxicol. 2010 Dec;48(12):3471-6. Key Finding: “Possibly as a result of higher amounts of quercetin and its derivatives, higher antimicrobial effects against Listeria monocytogenes and Salmonella typhimurium were observed for the organic white grape skin extracts.”
Organic foods contain higher levels of certain nutrients, lower levels of pesticides, and may provide health benefits for the consumer. Crinnion WJ. Altern Med Rev. 2010 Apr;15(1):4-12. Key Finding: “Studies of the nutrient content in organic foods vary in results due to differences in the ground cover and maturity of the organic farming operation. Nutrient content also varies from farmer to farmer and year to year. However, reviews of multiple studies show that organic varieties do provide significantly greater levels of vitamin C, iron, magnesium, and phosphorus than nonorganic varieties of the same foods. While being higher in these nutrients, they are also significantly lower in nitrates and pesticide residues. In addition, with the exception of wheat, oats and wine, organic foods typically provide greater levels of a number of important antioxidant phytochemicals.”
Polyphenol content and antiradical activity of Cichorium intybus L. from biodynamic and conventional farming. Heimler D, Isolani L, Vignolini P, Romani A. Food Chem. 2009 June 1;114(3):765-70. Key Finding: Conventional and organic-grown chicory was compared for its polyphenol content and antiradical activity during growing with severe water stress and without stress. Measurements of eight flavonoids found greatest negative changes in the conventional farming crop; antiradical activity was higher for the organic.
Comparison of phenolic acids in organically and conventionally grown pak choi (Bras-sica rapa L. chinensis). Zhao X, Nechols JR, William KA, Wang W, Carey EE. J Sci Food Agric. 2009;89(6): 940-46. Key Finding: in a field experiment, organic fertilization using compost and fish emulsion resulted in “significantly higher phenolic concentrations” compared with conventional chemical fertilization.
Yielding and fruit quality of three sweet pepper cultivars from organic and conventional cultivation. Szafirowska A, Elkner K. Vegetable Crops Research Bulletin (Poland). 2008;69:135-43. Key Finding: “The results revealed a good response of bell pepper to organic cultivation system. Pepper fruits obtained from organic cultivation system comprised higher amount of vitamin C, beta-carotene total flavonoids and polyphenols than from the conventional.”
Polyphenolic profile and antioxidant activity of five apple cultivators grown under organic and conventional agricultural practices. Valavanidis A, Vlachogianni T, Psomas A, Zovoili A, Siatis V. Int J Food Sci Tech. 2009 June; 44(6):1167-75. Key Finding: Polyphenols and total antioxidant activity of five apple cultivators grown by organic and conventional methods were analyzed. Polyphenolic concentrations “do not differentiate significantly between the organic and conventional apples.” Organic did show a slight advantage in antioxidant value.
Three-year comparison of the polyphenol contents and antioxidant capacities in organically and conventionally produced apples (Malus domestica Bork. Cultivar ‘Golden Delicious’). Stracke BA, Rufer CE, Weibel FP, Bub A, Watzi B. J Agric Food Chem. 2009 Jun 10;57(11):4598-605. Key Finding: “Apples grown under defined organic and conventional conditions were harvested at five comparable commercial farms over the course of three years (2004-06). In 2005 and 2006 the antioxidant capacity was 15% higher in organically produced apples than in conventionally produced fruits. In 2005 significantly higher polyphenol concentrations were found in the organically grown apples. In 2004 and 2006 no significant differences were observed.”
Comparison of physiochemical, microscopic and sensory characteristics of ecologically and conventionally grown crops of two cultivars of tomato. Ordonez-Santos L, Arbones-Macineira E, Fernandez-Perejon J, et al. J Sci Food Agric. 2009;89(5):743-49. Key Finding: “The statistically significant differences found in this study were mainly between cultivars rather than between tomatoes grown using different management practices.”
Nutritional quality of organic foods: a systematic review. Dangour AD, Dodhia SK, Hayter A, Lock AE, Uauy R. Am J Clin Nutr. 2009 Sep;90(3):680-5. Key Finding: “From a total of 52,471 articles, we identified 162 studies (137 crops and 25 livestock products); 55 were of satisfactory quality. On the basis of a systematic review of studies of satisfactory quality, there is no evidence of a difference in nutrient quality between organically and conventionally produced foodstuffs. The small differences in nutrient content detected are biologically plausible and mostly relate to differences in production methods.”
Environmental stresses induce health-promoting phytochemicals in lettuce. Oh MM, Carey EE, Rajashekar CB. Plant Physiol Biochem. 2009 Jul;47(7):578-83. Key Finding: “We have used mild environmental stresses (such a heat shock, chilling or high light intensity) to enhance the phytochemical content of lettuce. In response to these stresses, there was a two- to three-fold increase in the total phenolic content and a significant increase in the antioxidant capacity. The concentrations of two major phenolic compounds in lettuce, chicoric acid and chlorogenic acid, increased significantly in response to all of the stresses. Quercetin-3-0-glucoside and luteolin-7-0-glucoside were not detected in the control plants, but showed marked accumulations following the stress treatments. The results suggest that certain phenolic compounds can be induced in lettuce by environmental stresses. It is possible to use mild environmental stresses to successfully improve the phytochemical content and hence the health-promoting quality of lettuce with little or no adverse effect on its growth or yield.”
Antioxidant and antigenotoxic activities of purple grape juice – organic and conventional – in adult rats. Dani C, oliboni LS, Umezu FM, et al. J Med Food. 2009 Oct;12(5):1111-8. Key Finding: “The aim of this study was to evaluate the protection of organic and conventional purple grape juices in brain, liver, and plasma from adult Wistar rats against the oxidative damage provoked by carbon tetrachloride. The chemical and analytical determination showed that the highest levels of total phenolic, resveratrol, and catechins were seen in organic purples grape juices. In all treatment groups it was observed that in all tissue and plasma, treatment increased the lipid peroxidation levels. Both grape juices were capable to reduce LP levels in cerebral cortex and hippocampus; however, in the striatum and substantia nigra only the organic grape juice reduced LP level.”
Bioavailability and nutritional effects of carotenoids from organically and conventionally produced carrots in healthy men. Stracke BA, Rufer CE, Bub A, et al. Br J Nutr. 2009 Jun;101(11):1664-72. Key Finding: “Thirty-six volunteers consumed either organically or conventionally produced blanched carrots or no carrots in a double-blind, randomized intervention study. No statistically significant differences were observed in the total carotenoid contents of organic and conventional carrots.”
Health-promoting substances and heavy metal content in tomatoes grown with different farming techniques. Rossi F, Godani F, Bertuzzi T, et al. Eur J Nutr. 2008 August;47(5): 266-72. Key Finding: “Organic tomatoes contained more salicylic acid but less vitamin C and lycopene” than conventionally grown tomatoes. “Organic tomatoes had higher Cd and Pb levels but a lower Cu content. Organic fruits had a slightly higher protein content than conventionally cultivated fruits . . . their higher salicylate content support the notion that organic foodstuffs are more wholesome.”
Strawberry (Frafaria x ananassa Duch) fruit quality grown under different organic matter sources. Abu-Zahra TR, Tahboub AA. ISHA Acta Horticulturae 807: International Symposium on Strategies Towards Sustainability of Protected Cultivation in Mild Winter Climate. 2008. Key Finding: “Organic source treatments produced fruit with better color, higher dry matter, total phenols, crude fibre and carotene contents as compared to those produced by the control or conventional treatments. Also, the organic source treatments produced fruit with higher total soluble solids percentage and ascorbic acid content than with the conventional or the control treatments.”
Rats show differences in some biomarkers of health when eating diets based on ingredients produced with three different cultivation strategies. Lauridsen C, Yong C, Halekoh U, et al. J. Sci Food Agric. 2008;88:720-32. Key Finding: Rats were fed diets of vegetables and rapeseed oil from three different cultivation methods—organic, and two methods using pesticides and varying fertilizer inputs. Rats fed from a diet grown with pesticides and high fertilizer use showed lower health-related biomarkers in most categories measured than the organic.
Intake of purple grape juice as a hepatoprotective agent in Wistar rats. Dani C, Pasquali M, Oliveira MR, et al. J Med Food. 2008 March;11(1):127-32. Key Finding: “Antioxidant activities were significantly correlated with polyphenol content. Our findings suggest that the intake of purple grape juice, especially of organic juice, induces a better antioxidant capacity when compared to conventional juice.”
Antioxidant content in black currants from organic and conventional cultivation. Kazimierczak R, Hallmann E, Rusaczonek A, Rembialkowska E. EJPAU. 2008; 11(2). Key Finding: “The obtained results showed that organic black currant had considerably higher levels of compounds with anti-oxidant properties and higher antioxidant potential compared to fruits produced using conventional methods.”
Isoflavonoids, flavonoids, phenolic acids profiles and antioxidant activity of soybean seeds as affected by organic and bioorganic fertilization. Taie H, El-Mergawi R, Radwan S. American-Eurasian J Agric Environ Sci. 2008; 4(2):207-13. Key Finding: “Adding multi-bioorganic to 50% or 75% compost treatments produce great enhancement effects on total phenolics, total flavonoids, quercetin, genistein and daidzein contents as compared with other treatments.” Addition of organic treatments “resulted in 68% and 40% increases in quercetin and genistein, respectively, as compare with inorganic treatment.”
Comparison of lycopene, B-carotene and phenolic contents of tomato using conventional and ecologically horticultural practices, and arbuscular mycorrhizal fungi (AMF). Ulrichs C, Fischer G, Buttner C, Mewis i. Agron. Colomb. 2008 Jan/ June;26(1). Key Finding: “When comparing the cultivation method, no significant differences for the analyzed nutritional parameters were found; only tomatoes grown organically had slightly lower total phenolic contents. Organic grown tomatoes increased B-carotene and total phenolic contents in fruits as a result of the AMF treatment.”
The changes of the bioactive compounds in pickled red pepper fruits from organic and conventional production. Rembialkowska E, Hallmann E. J Research and Applications in Agriculture (Poland). 2008;53(4):51-7. Key Finding: “The obtained results of fresh red pepper showed that organic fruits contained more vitamin C, rutin, lutein, also dry matter. Conventional pepper contained more beta-carotene and lycopene.”
Comparison of polyamine, phenol and flavonoid contents in plants grown under conventional and organic methods. Lima GP. da Rocha SA. Takaki M. Ramos PR. Ono EO. Int J Food Sci Tech. 2008 Oct.;43(10):1838-43. Key Finding: Peels of zucchini, squash, banana, potato, eggplant, orange, lime, mango, passion fruit and radish, and leaves and stalks of zucchini, squash, broccoli, carrot, collard, cassava, radish, grape, and spinach were analyzed. “Most analysed vegetables presented higher contents of polyamines and total phenols under organic cropping, contrary to the results obtained for total flavonoids, possibly because of the cultural practices adopted.”
Fruit quality, antioxidant capacity, and flavonoid content of organically and conventionally grown blueberries. Wang SY, Chen CT, Sciarappa W, Wang CY, Camp MJ. J Agric Food Chem. 2008 July 23; 56(14):5788-94. Key Finding: “Results from this study showed that blueberry fruit grown from organic culture yielded significantly higher sugars (fructose and glucose), malic acid, total phenolics, total anthocyanins, and antioxidant activity (ORAC) than fruit from the conventional culture.”
A 3-year study on quality, nutritional and organoleptic evaluation of organic and conventional extra-virgin olive oils. Ninfali P, Bacchiocca M, Biagiotti E, et al. J Am Oil Chem Soc. 2008 Feb.;85(2):151-8. Key Finding: “The concentrations of phenols, o-diphenols, tocopherols, the antioxidant capacity and the volatile compounds showed differences in some years and no difference, or opposite differences, in others. Our results showed that organic versus conventional cultivation did not affect consistently the quality of the high quality EVOO considered in this study, at least in the measured parameters. Genotype and year-to-year changes in climate, instead, had more marked effects.”
Effects of agricultural practices on instrumental colour, mineral content, carotenoid composition, and sensory quality of mandarin orange juice, cv. Hernandina. Beltran-Gonzalez F, Perez-Lopez AJ, Lopez-Nicholas JM, Carbonell-Barrachina AA. J Sci Food Agric. 2008; 88(10):1731-38. Key Finding: “Organic farming of mandarin oranges resulted in juices with higher contents of minerals and carotenoids, and of better sensory quality. For instance, organic juice contained a total concentration of carotenoids of 14.4 mg L compared to 10.2 mg L of conventional juice.”
Effect of plant cultivation methods on content of major and trace elements in foodstuffs and retention in rats. Kirstensen M, Ostergaard LF, Halekoh U, et al. J Sci Food Agric2008; 88(2):2161-72. Key Finding: “This study does not support the belief that organically grown foodstuffs generally contain more major and trace elements than conventionally grown foodstuffs, nor does there appear to be an effect on the bioavailability of major and trace elements in rats.”
Wild and commercial mushrooms as source of nutrients and nutraceuticals. Barros L, Cruz T, Baptista P, Estevinho LM, Ferreira IC. Food Chem Toxicol. 2008 Aug;46(8):2742-7. Key Finding: Experiments were performed in wild and commercial species of mushrooms to analyze nutrient and phytochemical levels. Commercial species seemed to have higher concentrations of sugars, while wild species had higher contents of alpha-Tocopherol. Wild also had a higher content of phenols but a lower content of ascorbic acid than commercial species. There was no difference found in the antimicrobial properties of wild and commercial species.
Influence of irrigation and organic/inorganic fertilization on chemical quality of almond (Prunus amygdalus cv. Guara). Sanchez-Bel P, Egea I, Martinze-Madrd MC, Flores B, Romojaro F. J Agric Food Chem. 2008 Nov 12;56(21):10056-62. Key Finding: “Among the fertilizing treatments employed, the organic ones have shown the best results related to chemical quality, regardless of the quantity of fertilizer employed. The organic treatments produced almonds with a higher content of sugar, organic acids and fiber and a similar fat content.”
Organic vs Conventionally Grown Rio Red Whole Grapefruit and Juice: Comparison of Production Inputs, Market Quality, Consumer Acceptance, and Human Health-Bioactive Compounds. Lester GE. J Agric Food Chem. 2007 May 30;55(11): 4474-80. Key Finding: Conventionally grown fruit was higher in lycopene; organic fruit was higher in ascorbic acid and sugars.
Ten-year comparison of the influence of organic and conventional crop management practices on the content of flavonoids in tomatoes. Mitchell A, Hong YJ, Koh E, et al. J. Agric Food Chem. 2007 June 23;55(15): 6154-59. Key Finding: “Comparisons of analyses of archived samples from conventional and organic production systems demonstrated statistically higher levels of quercetin and kaempferol in organic tomatoes. Ten-year mean levels of quercetin and kaempferol in organic tomatoes were 79% and 97% higher than those in conventional tomatoes. The levels of flavonoids increased over time in samples from organic treatments, whereas the levels of flavonoids did not vary significantly in conventional treatments.”
Quality of plant products from organic agriculture. Rembialkowska E. J Sci Food Agric. 2007 Sep 21;87(15):2757-62. Key Finding: “Organic crops contain fewer nitrates, nitrites, and pesticide residues but, as a rule, more dry matter, vitamin C, phenolic compounds, essential amino acids and total sugars than conventional crops. Organic crops also contain statistically more mineral compounds.”
Yield and fruit quality response of sweet pepper to organic and mineral fertilization. Del Amor FM. Renew Agr Food Syst. 2007; 22: 233-8. Key Finding: “Organic farming increased antioxidant activity but reduced both chlorophylls and B-carotene.”
Phenolic content and antioxidant activities of white and purple juices manufactured with organically or conventionally produced grapes. Dani C, Oliboni LS, Vander-linde R, et al. Food Chem Toxicol. 2007 Dec;45(12): 2574-80. Key Finding: “Organic grape juices showed statistically different (p<0.05) higher values of total polyphenols and resveratrol as compared conventional grape juices. Purple juices presented higher total polyphenol content and in vitro antioxidant activity as compared to white juices.”
Antioxidant capacity of leafy vegetables as affected by high tunnel environment, fertilization and growth stage. Zhao X, Iwamoto T, Carey E. J Sci Food Agric. 2007;87(14):2692-99. Key Finding: “Organic fertilizer markedly increased the antioxidant capacity of pak choi compared with conventional treatment . . . in contrast to the first trial, organic fertilization did not cause an increase in antioxidant capacity of the leafy vegetables.”
Differential effect of organic cultivation on the levels of phenolics, peroxidase and capsidiol in sweet peppers. Del Amor FM, Serrano-Martinez A, Fortea I, Nunez-Delicado E. J Sci Food Agric. 2007 Dec 11;88(5):770-7. Key Finding: “Peroxidase activity in organic sweet peppers was higher than in conventional ones, in both maturity stages studied. The level of total phenolics compounds was also higher in organic than in conventional sweet peppers. With respect to the capsidiol activity, it was not affected by the cultivation method at the green mature stage. However, at the red mature stage, organic sweet peppers showed higher capsidiol activity than those grown under the conventional system.”
Nutritional quality of organic, conventional, and seasonally grown broccoli using vitamin C as a marker. Wunderlich SM, Feldman C, Kane S, Hazhin T. Int J Food Sci Nutr. 2008 Feb;59(1): 34-45. Key Finding: “Although the vitamin C content of organically and conventionally labeled broccoli was not significantly different, significant seasonal changes have been observed. The fall values for vitamin C were almost twice as high as those for spring for both varieties. The seasonal changes in vitamin C content are larger than the differences between organically labeled and conventionally grown broccoli.”
A comparative study of composition and postharvest performance of organically and conventionally grown kiwifruits. Amodio ML, Colelli G, Hasey JK, Kader AA. J Sci Food Agric. 2007; 87(7):1228-36. Key Finding: “All the main mineral constituents were more concentrated in organic kiwifruits, which also had higher levels of ascorbic acid and total phenol content, resulting in a higher antioxidant activity.”
Differential effect of organic cultivation on the levels of phenolics, peroxidase and capsidiol in sweet peppers. Del Amor FM, Serrano-Martinez A, Fortea I, Nunez-Delicado E. J Sci Food Agric. 2007;88(5):770-7. Key Finding: “Sweet peppers grown under organic culture have a maturity-related response with high levels of phenolic compounds and peroxidase and capsidiol activity that contribute to disease resistance in organic farming.” Organic sweet peppers had higher total phenolics and peroxidase activity and capsidiol activity than those grown under the conventional system.
Effects of agricultural practices on color, carotenoids composition, and minerals content of sweet peppers, cv. Almuden. Perez-Lopez AJ, Lopez-Nicholas JM, Nunez-Delicado E, Del Amor FM, Carbonell-Barrachina AA. J Agric Food Chem. 2007 Oct 3;55(20): 8158-64. Key Finding: “Experimental results proved that organic farming provided peppers with the highest (a) intensities of red and yellow colors (b) contents of minerals (c) total carotenoids. The concentrations of total carotenoids were 3231, 2493, and 1829 mg kg (-1) for organic, integrated, and conventional sweet peppers, respectively. Finally, organic red peppers could be considered as those having the highest antioxidant activity of all studied peppers.”
Antioxidant levels and inhibition of cancer cell proliferation in vitro by extracts from organically and conventionally cultivated strawberries. Olsson ME, Andersson CS, Oredsson S, Berglund RH, Gustavsson KE. J Agric Food Chem. 2006 Feb 22;54(4):1248-55. Key Finding: “The ratio of ascorbate to dehydroascorbate was significantly higher in the organically cultivated strawberries. The strawberry extracts decreased the proliferation of both HT29 colon cancer cells and MCF-7 breast cancer cells in a dose-dependent way. The inhibitory effect for the highest concentration of the extracts was in the range of 41%-63% inhibition compared to controls for the HT29 cells and 26%-56% for MCF-7 cells. The extracts from organically grown strawberries had a higher antiproliferative activity for both cell types at the highest concentration than the conventionally grown, and this might indicate a higher content of secondary metabolites with anticarcinogenic properties in the organically grown strawberries.”
High-Performance Liquid Chromatography Analysis of Black Currant (Ribes nigrum L.) Fruit Phenolics Grown either Conventionally or Organically. Antonnen MJ. Karjalainen RO. J Agric Food Chem. 2006, 54(20):7530-38. Key Finding: “Statistically significant differences between farms were found for almost all phenolic compounds,” ranging from 24% to 77% in values, but “it was concluded that the biochemical quality of organically grown black currant fruits does not differ from those grown conventionally.”
Antioxidant effectiveness of organically and nonorganically grown red oranges in cell culture systems. Tarozzi A, Hrelia S, Angeloni C, et al. . Eur J Nutr. 2006 April; 45(3):152-8. Key Finding: “The organic orange extracts had a higher total antioxidant activity than nonorganic orange extracts (p<0.05). Our results clearly show that organic red oranges have a higher phytochemical content (i.e. phenolics, anthocyanins and ascorbic acid), total antioxidant activity and bioactivity than integrated (nonorganic) red oranges.”
Influence of different types of fertilizers on the major antioxidant components of tomatoes. Toor RK, Savage GP, Heeb A. J Food Compost Anal. 2006 Feb;19():20-7. Key Finding: “The mean total phenolic and ascorbic acid content of tomatoes grown using chicken manure and grass-clover mulch (organic) was 17.6% and 29% higher, respectively, than the tomatoes grown with mineral nutrient solutions. The mean lycopene content was 40% lower in tomatoes grown with high chloride levels and grass-clover mulch compared with other treatments (chicken manure). The mean antioxidant activity of the ammonium-treated plants was 14% lower compared with other treatments.”
Quality of organically and conventionally grown potatoes: four-year study of micronutrients, metals, secondary metabolites, enzyme browning and organoleptic properties. Hajslova J, Schulzova V, Slanina P, et al. Food Addit Contam. 2005 June;22(6): 514-34. Key Finding: “The results indicated lower nitrate content and higher vitamin C and chlorogenic acid content to be the parameters most consistently differentiating organically from conventionally produced potatoes.”
Extracts from organically and conventionally cultivated strawberries inhibit cancer cell proliferation in vitro. Olsson ME, Andersson SC, Berglund RH, Gustavsson KE, Oredsson S. ISHS Acta Horticulturae 744: International Symposium on Human Health Effects of Fruits and Vegetables. 2005. Key Finding: “The strawberry extracts inhibited cell proliferation in colon cancer cells HT29 and breast cancer cells MCF-7 in a concentration dependent way. Extracts from organically grown strawberries inhibited cell proliferation to a higher extent than conventionally grown at the two highest concentrations. The content of ascorbate was 36% higher and the ratio of ascorbate to dehydroascorbate were eight-fold higher in the organically grown strawberries than in the conventionally grown. Ascorbate is suggested to act synergistically with other substances in the extracts.”
Sensory quality and mineral and glycoalkaloid concentrations in organically and conventionally grown redskin potatoes (Solanum tuberosum). Wszelaki AL, Delwiche JF, Walker SD, et al. J Sci Food Agric. 2005; 85:720-26. Key Finding: “Glycoalkaloid levels tended to be higher in organic potatoes. In tuber skin and flesh, potassium, magnesium, phosphorus, sulfur and copper concentrations were also significantly higher in organic treatments, while iron and manganese concentrations were higher in the skin of conventionally grown potatoes.”
Phenolic compounds in some apple (Malus domestica Borkh) cultivars of organic and integrated production. Veberic R, Trobec M, Herbinger K, et al. J Sci Food Agric. 2005 Mar 31;85(10):1687-94. Key Finding: “Organically grown apples exhibited a higher content of phenolic substances in the apple pulp compared with the apple cultivars of integrated production. The apple peel contained higher concentrations of identified phenols than the pulp.”
Phytochemical phenolics in organically grown vegetables. young JE, Zhao X, Carey E, et al. Mol Nutr Food Res. 2005;49(12):1136-42. Key Finding: “Statistically, we did not find significant higher levels of phenolic agents in lettuce and collard samples grown organically. The total phenolic content of organic pak choi samples as measured by the Folin-Ciocalteu assay, however, was significantly higher than conventional samples.”
Nutrients and antioxidant molecules in yellow plums (Prunus domestica L.) from conventional and organic productions: a comparative study. Lombard-Boccia G, Lu-carini M, Lanzi S, Aguzzi A, Cappelloni M. J AgricFood Chem. 2004; 52(1): 90-94. Key Finding: Ascorbic acid, y-tocopherols, and B-carotene were higher in organic plums grown on soil with natural meadow. Total polyphenols content and quercetin were higher in conventional plums. Myrecitin and kaempferol were higher in organic plums.
Grain mineral concentrations and yield of wheat grown under organic and conventional management. Ryan MH, Derrick JW, Dann PR. J Sci Food Agric. 2004;84(3):207-16. Key Finding: Conventional grain had lower Zn and Cu, but higher Mn and P than organic grain. “These variations in grain minerals had nutritional implications primarily favouring the organic grain.”
Influence of organic versus conventional agricultural practices on the antioxidant micro-constituent content of tomatoes and derive purees; consequences on antioxidant plasma status in humans. Caris-Veyrat C, Amiot MJ, Tyssandier V, et al. J Agric Food Chem. 2004 Oct;52(21):6503-9. Key Finding: “In tomato purees, no difference in carotenoid content was found between the two modes of culture, whereas the concentrations of vitamin C and polyphenols remained higher in purees made out of organic tomatoes.”
Changes in USDA food composition data for 43 garden crops, 1950 to 1999. Davis DR, Epp MD, Riordan HD. J Am Coll Nutr. 2004;23(6):669-82. Key Finding: Statistically reliable declines were found for 6 nutrients (protein, Ca, P, Fe, riboflavin and ascorbic acid). Declines ranged from 6% for protein to 38% for riboflavin. These measurements were taken from nonorganic crops in the 43 crop categories.
Comparison of the total phenolic and ascorbic acid content of freeze-dried and air-dried marionberry, strawberry, and corn grown using conventional, organic, and sustainable agricultural practices. Asami DK, Hong YJ, Barrett DM, Mitchell A. J Agric Food Chem. 2003;51(5):1237-41. Key Finding: “Statistically higher levels of total phenolics were consistently found in organically and sustainably grown foods as compared to those produced by conventional agricultural practices.” Organically grown corn and marionberries contained up to 65% more phenolic compounds than conventionally grown crops, while organic strawberries contained 19% more.
Organically produced plant foods – evidence of health benefits. Lundegardh B, Martensson A. Agriculturae Scandinavica. 2003;Section B. Key Finding: “It is a reasonable assumption that organic foods can strengthen the immune system and other defense systems depending on an interaction between various favourable properties of the organic foods.”
Organic food: nutritious food or food for thought? A review of the evidence. Magkos F, Arvaniti F, Zampelas A. Int J Food Sci Nutr. 2003 Sep;54(5):357-71. Key Finding: “Although there is little evidence that organic and conventional foods differ in respect to the concentrations of the various micronutrients (vitamins, minerals and trace elements), there seems to be a slight trend towards higher ascorbic acid content in organically grown leafy vegetables and potatoes.” Protein concentration is of higher quality in some organic vegetables and “animal feeding experiments indicate that animal health and reproductive performance are slightly improved when they are organically fed.”
Effect of diets based on foods from conventional versus organic production on intake and excretion of flavonoids and markers of antioxidative defense in humans. Grinder-Pedersen L, Rasmussen SE, Bugel S, et al. J. Agric. Food Chem. 2003;51:5671-76. Key Finding: “The food production method affected the content of the major flavonoid, quercetin, in foods and also affected urinary flavonoids and markers of oxidation in humans.” Urinary excretion of quercetin and kaempferol was higher after 22 days on intake of the organically produced diet when compared to the conventionally produced.
Modulation of antioxidant compounds in organic vs conventional fruit (peach, Prunus persica L., and pear, Pyrus communis L.) Carbonaro M, Mattera M, Nicoli S, Bergamo P, Cappelloni M. J Agric Food Chem. 2002; 50(19):5458-62. Key Finding: “A parallel increase in polyphenol content and PPO activity of organic peach and pear as compared with the corresponding conventional samples was found. Ascorbic and citric acids were higher in organic than conventional peaches, whereas a-tocopherol was increased in organic pear. These data provide evidence that an improvement in the antioxidant defense system of the plant occurred as a consequence of the organic cultivation practice.”
Nutritional quality of organic food: shades of grey or shades of green? Williams CM. Proc Nutr Soc. 2002;61:19-24. Key Finding: “There are reasonably consistent findings for higher nitrate and lower vitamin C contents of conventionally produced vegetables, particularly leafy vegetables,” compared to organic produce.
Salicylic acid in soups prepared from organically and nonorganically grown vegetables. Baxter GJ, Graham AB, Lawrence JR, Wiles D, Paterson JR. Eur J Nutr. 2001 Dec;40(6):289-92. Key Finding: “Organic vegetable soups contained more salicylic acid (almost six times) than nonorganic ones, suggesting that the vegetables and plants used to prepare them contained greater amounts of the phenolic acid than the corresponding nonorganic ingredients. Consumption of organic foods may result in a greater intake of salicylic acid.”
Polyphenoloxidase activity and polyphenol levels in organically and conventionally grown peach (Prunus persica L., cv. Regina Bianca) and pear (Pyrus communis L., cv. Williams). Carbonaro M, Mattera M. Food Chem. 2001 March;72(4):419-24. Key Finding: “All organic peach samples showed a highly significant (P<0.001) increase in polyphenols compared with conventional peaches, while, of the three organic pear samples, two displayed an increased polyphenol content with respect to the conventionally grown sample. Activity of PPo was significantly higher in most of the organic peach and pear samples.”
Organic agriculture: does it enhance or reduce the nutritional value of plant foods? Brandt K, Molgaard JP. J Sci Food Agric. 2001;81(9):924-31. Key Finding: “There is ample, but circumstantial, evidence that, on average, organic vegetables and fruits most likely contain more of these compounds (minerals, vitamins, proteins, etc.) than conventional ones, allowing for the possibility that organic plant foods may in fact benefit human health more than corresponding conventional ones.”
Nutritional quality of organic versus conventional fruits, vegetables, and grains. Worthington V. J Altern Complement Med. 2001 Apr; 7(2):161-73. Key Finding: “organic crops contained significantly more vitamin C, magnesium, and phosphorus and significantly less nitrates than conventional crops. There appear to be genuine differences in the nutrient content of organic and conventional crops.”
Organic Farming, Food Quality and Human Health: A Review of the Evidence. Heaton, Shane. Soil Association Ltd., Bristol (United Kingdom). 2001. Available at http://www.soilassociation.org/LinkClick.aspx?fileticket=cY8kfP3Q%2BgA%3D&tabid=388. Accessed on 27 May 2011. Key Finding: “Viewed collectively the valid and relevant scientific evidence indicates that organically grown foods are significantly different in terms of their safety, nutritional content and nutritional value from those produced by nonorganic farming.”
Production of lettuce under different fertilisation treatments, yield and quality. Premuzic Z, Garate A, Bonilla I. ISHA Acta Horticulturae 571: Workshop Towards Ecologically Sound Fertilisation in Field Vegetable Production. 2000. Key Finding: Four fertilizer treatments were applied to lettuce—two organic (vermicompost and biostabilised compost) and two inorganic. “Vermicompost presented the best result, i.e. a high yield, a low nitrate content and a high vitamin C content.”
Comparative investigation of concentrations of major and trace elements in organic and conventional Danish agricultural crops. Onions (Allium cepa Hysam) and peas (Pisum sativum Ping Pong). Gundersen V, Bechmann IE, Behrens A, Sturup S. J Agric Food Chem. 2000; 48(12): 6094-102. Key Finding: “Comparative statistical tests of the element concentration mean values for each site show significantly (p<0.05) different levels of Ca, Mg, B, Bi, Dy, Eu, Gd, Lu, Rb, Sb, Se, Sr, Ti, U and Y between the organically and conventionally grown onions and significantly (p<0.05) different levels of P, Gd, and Ti between the organically and conventionally grown peas.”
Effect of agricultural methods on nutritional quality: a comparison of organic with conventional crops. V. Worthington. Altern-Ther-Health-Med. 1998 Jan;4(1):58-69. Key Finding: “Existing studies show that organic fertilization practices produce crops with higher levels of ascorbic acid, lower levels of nitrate, and improved protein quality compared with conventionally grown crops.”
Are organically grown apples tastier and healthier? A comparative field study using conventional and alternative methods to measure fruit quality. Weibel FP, Bickel R, Leuthold S, Alfoldi T. ISHS Acta Horticulturae 517: XXV International Horticultural Congress, Part 7: Quality of Horticultural Products. 1998. Key Finding: P-content was 31% higher (p<0.01) in organic apples. Content of phenols (mainly flavanols) was 19% and image forming quality 60% higher in organic apples.
Yield, vitamin and mineral contents of organically and conventionally grown potatoes and sweet corn. Warman PR, Havard KA. Agric Ecosyst Environ 1998 April;68(3): 207-16. Key Finding: There was no difference between treatments in the vitamin C or E contents of corn. In organically fertilized potatoe plots the P, Ca, Mg and Cu were higher. Mg content was higher in the organic corn.
Yield, vitamin and mineral contents of organically and conventionally grown carrots and cabbage. Warman PR, Havard KA, Agric Ecosyst Environ. 1997 Feb;61(2-3): 155-62. Key Finding: “Analysis of the 3 years of data showed that the yield and vitamin content of the carrots and cabbages were not affected by treatments. Five elements in carrot roots (N, S, Mn, Cu, B) and two elements in carrot leaves (S, Na) were influenced by treatments; in cabbages, N, Mn, and Zn were affected.”
Historical changes in the mineral content of fruits and vegetables. Mayer AM. British Food Journal. 1997;99(6):20711. Key Finding: A comparison of the mineral content of 20 fruits and 20 vegetables grown in the 1930s and the 1980s (published in the UK government’s Composition of Foods tables) shows several marked reductions in mineral content. There are statistically signficiant reductions in the levels of Ca, Mg, Cu and Na in vegetables and Mg, Fe, Cu and K in fruit. The only mineral over the 50-year period that showed no significant difference was P. These differences could have been caused by changes in agricultural practices.
A comparison of organically and conventionally grown foods – results of a review of the relevant literature. Woese K, Lange D, Boess C, Bogl KW. J Sci Food Agric. 1997;74:281-93. Key Finding: 150 studies comparing organic to conventional were reviewed covering cereals, potatoes, vegetables, fruits, wine, beer, bread, cakes, milk, meat, eggs and honey, as well as products made from them. About 100 of the studies dealt with potatoes, vegetables, fruits and nuts. From among those studies, the following trends were identified—organic potatoes had higher phosphorus and potassium levels than conventionally grown, and some studies showed that organic contained higher vitamin C, while other studies showed no difference. There were clear findings that organic vegetables had a lower nitrate content than conventional; in half of the studies organic vegetables had a higher iron content, otherwise, no differences were observed in the contents of minerals and trace elements between organic and conventional products. Vitamin C in organic vegetables was found to be higher by roughly half of the studies, while the other half found no major difference. Higher Vitamin C content was particularly noted in organic lettuce, savoy cabbage, spinach, and chard (leaf beet). Few studies addressed qualitative differences between fruit, nuts and oil seeds from organic and conventional cultivation. As a last observation from the studies, “animals distinguish between the foods on offer from the various agricultural systems and almost exclusively prefer organic produce.”
Organic foods vs supermarket foods: element levels. Smith BL. J Appl Nutr. 1993;45:35-39. Key Finding: Over a two-year period the mineral content of organically and conventionally grown apples, corn, pears, potatoes, and wheat was analyzed in Chicago. “The average elemental concentration in organic foods on a fresh weight basis was found to be about twice that of commercial foods.” Organic foods were higher than conventionally grown in these eight mineral categories: calcium 63% higher; chromium 78% higher; iodine 73% higher; iron 59% higher; magnesium 138% higher; potassium 125% higher; selenium 390% higher; and zinc, 60% higher.