Hostname: page-component-cd9895bd7-8ctnn Total loading time: 0 Render date: 2024-12-23T09:12:13.828Z Has data issue: false hasContentIssue false

Putting the safety of organic food into perspective

Published online by Cambridge University Press:  14 December 2007

Faidon Magkos
Affiliation:
Laboratory of Nutrition and Clinical Dietetics, Department of Nutrition and Dietetics, Harokopio University, 70 El. Venizelou Avenue, 17671 Athens, Greece
Fotini Arvaniti
Affiliation:
Laboratory of Nutrition and Clinical Dietetics, Department of Nutrition and Dietetics, Harokopio University, 70 El. Venizelou Avenue, 17671 Athens, Greece
Antonis Zampelas*
Affiliation:
Laboratory of Nutrition and Clinical Dietetics, Department of Nutrition and Dietetics, Harokopio University, 70 El. Venizelou Avenue, 17671 Athens, Greece
*
*Corresponding author: Dr Antonis Zampelas, fax +30 210 9577050, email [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The demand for organic foods is constantly increasing mainly due to consumers' perception that they are healthier and safer than conventional foods. There is a need for information related to food safety to inform consumers of the health benefits and/or hazards of food products of both origins, in order to optimise the impact on health and minimise the risks. Several gaps and limitations in scientific knowledge with regard to food risk evaluation make it difficult to draw generalised conclusions. Still, some organic foods can be expected to contain fewer agrochemical residues and lower levels of nitrate than conventionally grown alternatives. On the other hand, environmental contaminants are equally present in foods of both origins. With regard to other food hazards, such as natural chemicals, microbial pathogens and mycotoxins, no clear conclusions can be drawn, although several interesting points can be highlighted. It is difficult, therefore, to weigh the risks, but what should be made clear to consumers is that ‘organic’ does not equal ‘safe’. If producers adopt proper agricultural practices and consumers maintain hygienic conditions, risks associated with food contaminants can be minimised, regardless of the food's organic or conventional origin.

Type
Research Article
Copyright
Copyright © The Authors 2003

References

Agrawal, AA (2000) Mechanisms, ecological consequences and agricultural implications of tri-trophic interactions. Current Opinion in Plant Biology 3, 329335.CrossRefGoogle ScholarPubMed
Albihn, A (2001) Recycling biowaste – human and animal health problems. Acta Veterinaria Scandinavica Supplementum 95, 6975.Google Scholar
American Dietetic Association (1990 a) More on organic foods. Journal of the American Dietetic Association 90, 920922.Google Scholar
American Dietetic Association (1990 b) Organic foods: are they better? Journal of the American Dietetic Association 90, 367370.Google Scholar
Ames, BN & Gold, LS (1990) Chemical carcinogenesis: too many rodent carcinogens. Proceedings of the National Academy of Sciences USA 87, 77727776.CrossRefGoogle ScholarPubMed
Ames, BN, Profet, M & Gold, LS (1990 a) Dietary pesticides (99·99 % all natural). Proceedings of the National Academy of Sciences USA 87, 77777781.CrossRefGoogle ScholarPubMed
Ames, BN, Profet, M & Gold, LS (1990 b) Nature's chemicals and synthetic chemicals: comparative toxicology. Proceedings of the National Academy of Sciences USA 87, 77827786.Google Scholar
Avery, AA (2001) Cause of methemoglobinemia: illness versus nitrate exposure. Environmental Health Perspectives 109, A12–A14.CrossRefGoogle ScholarPubMed
Baker, BP, Benbrook, CM, Groth, E 3 & Lutz Benbrook, K (2002) Pesticide residues in conventional, integrated pest management (IPM)-grown and organic foods: insights from three US data sets. Food Additives and Contaminants 19, 427446.Google Scholar
Bashan, N, Burdett, E, Guma, A, Sargeant, R, Tumiati, L, Liu, Z & Klip, A (1993) Mechanisms of adaptation of glucose transporters to changes in the oxidative chain of muscle and fat cells. American Journal of Physiology 264, C430–C440.Google Scholar
Betarbet, R, Sherer, TB, MacKenzie, G, Garcia-Osuna, M, Panov, AV & Greenamyre, JT (2000) Chronic systemic pesticide exposure reproduces features of Parkinson's disease. Nature Neuroscience 3, 13011306.Google Scholar
Beuchat, LR & Ryu, JH (1997) Produce handling and processing practices. Emerging Infectious Diseases 3, 459465.Google Scholar
Birchurd, K (2001) Europe tackles consumers fears over food safety. Lancet 357, 1276.Google Scholar
Bourn, D & Prescott, J (2002) A comparison of the nutritional value, sensory qualities, and food safety of organically and conventionally produced foods. Critical Reviews in Food Science and Nutrition 42, 134.Google Scholar
Bourn, DM (1994) The nutritional value of organically and conventionally grown food – is there a difference? Proceedings of the Nutrition Society of New Zealand 19, 5157.Google Scholar
Brandt, K & Molgaard, JP (2001) Organic agriculture: does it enhance or reduce the nutritional value of plant foods? Journal of the Science of Food and Agriculture 81, 924931.CrossRefGoogle Scholar
Buttriss, J & Hughes, J (2000) An update on copper: contribution of MAFF-funded research. Nutrition Bulletin 25, 271280.Google Scholar
Carpy, SA, Kobel, W & Doe, J (2000) Health risk of low-dose pesticides mixtures: a review of the 1985–1998 literature on combination toxicology and health risk assessment. Journal of Toxicology and Environmental Health Part B: Critical Reviews 3, 125.Google Scholar
Centers for Disease Control (1999) From the Centers for Disease Control and Prevention: Safer and healthier foods, 1900–1999. Journal of the American Medical Association 282, 19091912.CrossRefGoogle Scholar
Chamberlain, DE, Wilson, JD & Fuller, RJ (1999) A comparison of bird populations on organic and conventional farm systems in southern Britain. Biological Conservation 88, 307320.CrossRefGoogle Scholar
Cieslak, PR, Barrett, TJ, Griffin, PM, Gensheimer, KF, Beckett, G, Buffington, J & Smith, MG (1993) Escherichia coli O157:H7 infection from a manured garden. Lancet 342, 367.CrossRefGoogle ScholarPubMed
Cliver, DO (editor) (1999) Eating Safely: Avoiding Foodborne Illness. New York, NY: American Council on Science and Health.Google Scholar
Coggon, D & Inskip, H (1994) Is there an epidemic of cancer? British Medical Journal 308, 705708.CrossRefGoogle ScholarPubMed
Committee on Comparative Toxicity of Naturally Occurring Carcinogens (1996) Carcinogens and Anticarcinogens in the Human Diet: A Comparison of Naturally Occurring and Synthetic Substances. Washington DC: National Academy Press.Google Scholar
Connett, E & Connett, P (2001) Fluoride: the hidden poison in the National Organic Standards. Pesticides and You 21, 1822.Google Scholar
Crutchfield, SR & Cooper, J (1997) Valuing risk reduction: the example of nitrates in drinking water. FoodReview 20, 3841.Google Scholar
Crutchfield, SR & Roberts, T (2000) Food safety efforts accelerate in the 1990s. FoodReview 23, 4449.Google Scholar
Dewhurst, IC (2001) Toxicological assessment of biological pesticides. Toxicology Letters 120, 6772.CrossRefGoogle ScholarPubMed
Dorman, DC & Beasley, VR (1991) Neurotoxicology of pyrethrin and the pyrethroid insecticides. Veterinary and Human Toxicology 33, 238243.Google ScholarPubMed
Doyle, MP (2000) Reducing foodborne disease: what are the priorities?. Nutrition 16, 647–649.CrossRefGoogle ScholarPubMed
Duggan, RE, Barry, HC & Johnson, LY (1966) Pesticide residues in total-diet samples. Science 151, 101104.Google Scholar
Eltun, R (1996) The Apelsvoll cropping system experiment. 3. Yield and grain quality of cereals. Norwegian Journal of Agricultural Science 10, 721.Google Scholar
Engvall, A (2001) May organically farmed animals pose a risk for Campylobacter infections in humans?. Acta Veterinaria Scandinavica Supplementum 95, 8587.Google Scholar
Eppendorfer, WH & Eggum, BO (1992) Dietary fibre, sugar, starch and amino acid content of kale, ryegrass and seed of rape and field beans as influenced by S- and N-fertilization. Plant Foods for Human Nutrition 42, 359371.Google Scholar
Fan, AM & Jackson, RJ (1989) Pesticides and food safety. Regulatory Toxicology and Pharmacology 9, 158174.CrossRefGoogle ScholarPubMed
Fisher, AC & Worth, W (editors) (1995) Update: Is There a Cancer Epidemic in the United States? New York, NY: American Council on Science and Health.Google Scholar
Fisher, BE (1999) Organic: What's in a name?. Environmental Health Perspectives 107, A150'A153.CrossRefGoogle Scholar
Food and Agriculture Organization (1999) FAO Committee on Agriculture. 15th Session: Organic Agriculture. Rome: Food and Agriculture Organization.Google Scholar
Food and Agriculture Organization/World Health Organization (2001 a) Guidelines for the Production, Processing, Labelling and Marketing of Organically Produced Foods. Rome Italy: Codex Alimentarius Commission and Joint FAO/WHO Food Standards Programme.Google Scholar
Food and Agriculture Organization/World Health Organization (2001 b) The WHO Surveillance Programme for Control of Foodborne Infections and Intoxications in Europe: 7th Report on Surveillance of Foodborne Diseases in Europe 1993–1998 [Tirado, C and Schmidt, K editors]. Berlin Germany: FAO/WHO Collaborating Centre for Training and Research in Food Hygiene and Zoonoses.Google Scholar
Gade, PB. (2002) Welfare of animal production in intensive and organic systems with special reference to Danish organic pig production. Meat Science 62, 353358.CrossRefGoogle ScholarPubMed
Gilbert, J & Shepherd, MJ (1985) A survey of aflatoxins in peanut butters, nuts and nut confectionery products by HPLC with fluorescence detection. Food Additives and Contaminants 2, 171183.CrossRefGoogle ScholarPubMed
Gonzalez, M, Miglioranza, KS, Aizpun de Moreno, JE & Moreno, VJ (2003) Occurrence and distribution of organochlorine pesticides (OCPs) in tomato (Lycopersicon esculentum) crops from organic production. Journal of Agricultural and Food Chemistry 51, 13531359.Google Scholar
Gorbach, SL (2001) Antimicrobial use in animal feed – time to stop. New England Journal of Medicine 345, 12021203.Google Scholar
Greene, C (2000) US Organic agriculture gaining ground. Agricultural Outlook 270, 914.Google Scholar
Greene, C (2001) Organic labeling. In Economics of Food Labeling, pp.2629. [Golan, E, Kuchler, F, Mitchell, L, Greene, C and Jessup, A editors]. Washington DC: USDA/Economic Research Service.Google Scholar
Hamer, DH & Gill, CJ (2002) From the farm to the kitchen table: the negative impact of antimicrobial use in animals on humans. Nutrition Reviews 60, 261264.Google Scholar
Hamilton-Miller, JM & Shar, S (2001) Identity and antibiotic susceptibility of enterobacterial flora of salad vegetables. International Journal of Antimicrobial Agents 18, 8183.Google Scholar
Harborne, JB (1990) Role of secondary metabolites in chemical defence mechanisms in plants. Ciba Foundation Symposium 154, 126134.Google Scholar
Havender, WR (editor) (1993) Does Nature Know Best? Natural Carcinogens and Anticarcinogens in America's Food. New York, NY: American Council on Science and Health.Google Scholar
Heaton, S (2001) Organic Farming, Food Quality and Human Health: A review of the evidence. Bristol UK: Soil Association.Google Scholar
Isenberg, JS & Klaunig, JE (2000) Role of the mitochondrial membrane permeability transition (MPT) in rotenone-induced apoptosis in liver cells. Toxicological Sciences 53, 340351.Google Scholar
Jones, KC, Symon, CJ & Johnston, AE (1987) Retrospective analysis of an archived soil collection. II. Cadmium. The Science of the Total Environment 67, 7589.Google Scholar
Jorgensen, K, Rasmussen, G & Thorup, I (1996) Ochratoxin A in Danish cereals 1986–1992 and daily intake by the Danish population. Food Additives and Contaminants 13, 95104.CrossRefGoogle ScholarPubMed
Jorhem, L & Slanina, P (2000) Does organic farming reduce the content of Cd and certain other trace metals in plant foods? A pilot study. Journal of the Science of Food and Agriculture 80, 4348.3.0.CO;2-Y>CrossRefGoogle Scholar
Jukes, TH (1974) The organic food myth. Journal of the American Medical Association 230, 276277.Google Scholar
Jukes, TH (1975) What you can tell your patients about ‘organic’ foods. Medical Times 103, 7581.Google ScholarPubMed
Jukes, TH (1979) Organic food. Critical Reviews in Food Science and Nutrition 9, 395418.Google Scholar
Jukes, TH (1990) Organic apple juice no antidote for alar. Journal of the American Dietetic Association 90, 371.Google Scholar
Karavoltsos, S, Sakellari, A, Dimopoulos, M, Dasenakis, M & Scoullos, M (2002) Cadmium content in foodstuffs from the Greek market. Food Additives and Contaminants 19, 954962.Google Scholar
Keene, WE (1999) Lessons from investigations of foodborne disease outbreaks. Journal of the American Medical Association 281, 18451847.CrossRefGoogle ScholarPubMed
Kirchmann, H & Thorvaldsson, G (2000) Challenging targets for future agriculture. European Journal of Agronomy 12, 145161.CrossRefGoogle Scholar
Kuiper-Goodman, T (1999) Approaches to the risk analysis of mycotoxins in the food supply. Food, Nutrition and Agriculture 23, 1016.Google Scholar
Kumpulainen, J (2001) Organic and conventional grown foodstuffs: Nutritional and toxicological quality comparisons. Proceedings of the International Fertiliser Society 472, 120.Google Scholar
Lecerf, JM (1995) Biological agriculture: interest for human nutrition?. Cahiers de Nutrition et de Dietetique 30, 349357.Google Scholar
Linden, A, Andersson, K & Oskarsson, A (2001) Cadmium in organic and conventional pig production. Archives of Environmental Contamination and Toxicology 40, 425431.Google Scholar
Lohr, L (2001) Factors affecting international demand and trade in organic food products. In Changing Structure of Global Food Consumption and Trade. pp.6779. [Regmi, A editor]. Washington DC: USDA/Economic Research Service.Google Scholar
Loken, T (2001) Alternative therapy of animals – homeopathy and other alternative methods of therapy. Acta Veterinaria Scandinavica Supplementum 95, 4750.Google Scholar
Lovejoy, SB (1994) Are organic foods safer? Austin, TX: Texas Botanical Garden Society (TBGS) Newsletter. http://www.greensmiths.com/organicfoods.htmGoogle Scholar
McCarrison, R (1926) The effect of manurial conditions on the nutritive and vitamin values of millet and wheat. Indian Journal of Medical Research 14, 351378.Google Scholar
MacKenzie, D (1993) Disease could wipe out Baltic salmon. New Scientist 140, 8.Google Scholar
MacKenzie, D (1999) Red flag for green spray: even organic farming is not immune to health scares. New Scientist 162, 4.Google Scholar
MacKerron, DKL, Duncan, JM, Hillman, JR, Mackay, GR, Robinson, DJ, Trudgill, DL & Wheatley, RJ (1999) Organic farming: science and belief. In Annual Report 1998/1999 6072. [Macfarlane Smith, WH and Heilbronn, TD editors]. Dundee Scotland: Scottish Crop Research Institute.Google Scholar
McKnight, GM, Duncan, CW, Leifert, C & Golden, MH (1999) Dietary nitrate in man: friend or foe? British Journal of Nutrition 81, 349358.Google Scholar
McMahon, MA & Wilson, IG (2001) The occurrence of enteric pathogens and Aeromonas species in organic vegetables. International Journal of Food Microbiology 70, 155162.Google Scholar
Mader, P, Fliessbach, A, Dubois, D, Gunst, L, Fried, P & Niggli, U (2002) Soil fertility and biodiversity in organic farming. Science 296, 16941697.Google Scholar
Magkos, F, Arvaniti, F & Zampelas, A (2003) Organic food: nutritious food or food for thought? A review of the evidence International Journal of Food Sciences and Nutrition 54, 537–371.Google Scholar
Magleby, R (1998) Farmers' use of ‘green’ practices varies widely. Agricultural Outlook 248, 2227.Google Scholar
Malmauret, L, Parent-Massin, D, Hardy, JL & Verger, P (2002) Contaminants in organic and conventional foodstuffs in France. Food Additives and Contaminants 19, 524532.Google Scholar
Marcus, MB (2001) Organic foods offer peace of mind – at a price. US News and World Report 130, 4850.Google Scholar
Marx, H, Gedek, B & Kollarczik, B (1994) Comparative studies of the bacterial and mycological status of ecologically and conventionally grown crops. European Journal of Nutrition 33, 239243.Google Scholar
Marx, H, Gedek, B & Kollarczik, B (1995) Comparative investigations of mycotoxological status of alternatively and conventionally grown crops. European Food Research and Technology 201, 8386.Google Scholar
Mathews, KHJ, Buzby, JC, Tollefson, LR & Dargatz, DA (2001) Livestock drugs: More questions than answers? Agricultural Outlook 271, 1821.Google Scholar
Mattsson, JL (2000) Do pesticides reduce our total exposure to food borne toxicants? Neurotoxicology 21, 195202.Google Scholar
Mead, PS, Slutsker, L, Dietz, V, McCaig, LF, Bresee, JS, Shapiro, C, Griffin, PM & Tauxe, RV (1999) Food-related illness and death in the United States. Emerging Infectious Diseases 5, 607625.Google Scholar
Mislivec, PB, Bruce, VR & Andrews, WH (1979) Mycological survey of selected health foods. Applied and Environmental Microbiology 37, 567571.Google Scholar
Mitchell, L & Normile, MA (1999) Consumer concerns elicit policy changes. In The European Union's Common Agricultural Policy: Pressures for Change, pp.4552. [Kelch, DR editor]. Washington DC: USDA/Economic Research Service.Google Scholar
Moolenaar, S (1999) The dirt on organic farming. Environmental News Network. http://www.enn.com/news/enn-stories/1999/02/ 021199/farming_1573.aspGoogle Scholar
Moolenaar, SW & Lexmond, TM (1999) Heavy metal balances, Part I: General aspects of cadmium copper, zinc, and lead balance studies in agro-ecosystems. Journal of Industrial Ecology 2, 4560.,Google Scholar
Moreira M del, RRoura, SI & del Valle, CE (2003) Quality of Swiss chard produced by conventional and organic methods. Food Science and Technology 36, 135141.Google Scholar
Morkeberg, A & Porter, JR (2001) Organic movement reveals a shift in the social position of science. Nature 412, 677Google Scholar
Nakamura, Y, Tonogai, Y, Tsumura, Y & Ito, Y (1993) Determination of pyrethroid residues in vegetables, fruits, grains, beans, and green tea leaves: applications to pyrethroid residue monitoring studies. Journal of AOAC International 76, 13481361.Google Scholar
Naska, A, Vasdekis, VG, Trichopoulou, A, Friel, S, Leonhauser, IU, Moreiras, O, Nelson, M, Remaut, AM, Schmitt, A, Sekula, W, Trygg, KU & Zajkas, G (2000) Fruit and vegetable availability among ten European countries: how does it compare with the ‘five-a-day’ recommendation? DAFNE I and II projects of the European Commission. British Journal of Nutrition 84, 549556.Google Scholar
Ogbondeminu, FS & Okaeme, AN (1986) Bacterial flora associated with an organic manure-aquaculture system in Kainji Lake Basin area, Nigeria. International Journal of Zoonoses 13, 5458.Google Scholar
Oppenheim, M (1971) Rancorous consumer of ‘organic’ food. New England Journal of Medicine 284, 859.Google Scholar
Pell, AN (1997) Manure and microbes: public and animal health problem? Journal of Dairy Science 80, 26732681.CrossRefGoogle ScholarPubMed
Pobel, D, Riboli, E, Cornee, J, Hemon, B & Guyader, M (1995) Nitrosamine, nitrate and nitrite in relation to gastric cancer: a case-control study in Marseille, France. European Journal of Epidemiology 11, 6773.Google Scholar
Poulsen, N, Johansen, AS & Sorensen, JN (1995) Influence of growth conditions on the value of crisphead lettuce. 4. Quality changes during storage. Plant Foods for Human Nutrition 47, 157162.Google Scholar
Ren, H, Endo, H & Hayashi, T (2001) The superiority of organically cultivated vegetables to general ones regarding antimutagenic activities. Mutation Research 496, 8388.Google Scholar
Schollenberger, M, Suchy, S, Jara, HT, Drochner, W & Muller, HM (1999) A survey of Fusarium toxins in cereal-based foods marketed in an area of southwest Germany. Mycopathologia 147 4957.Google Scholar
Schollenberger, M, Jara, HT, Suchy, S, Drochner, W & Muller, HM (2002) Fusarium toxins in wheat flour collected in an area in southwest Germany. International Journal of Food Microbiology 72, 8589.Google Scholar
Shaw, I (2002) Pesticides residues in food. Journal of Environmental Monitoring 2, 34N–37N.Google Scholar
Silkworth, JB & Brown, JF Jr (1996) Evaluating the impact of exposure to environmental contaminants on human health. Clinical Chemistry 42, 13451349.Google Scholar
Smith, RA & Barry, JW (1998) Environmental persistence of Bacillus thuringiensis spores following aerial application. Journal of Invertebrate Pathology 71, 263267.Google Scholar
Soil Association (1997) Standards for Organic Food and Farming Bristol UK: The Soil Association Organic Marketing Co Ltd.Google Scholar
Soil Association (2000) The Biodiversity Benefits of Organic Farming Bristol UK: The Soil Association.Google Scholar
Subar, AF, Heimendinger, J, Patterson, BH, Krebs-Smith, SM, Pivonka, E & Kessler, R (1995) Fruit and vegetable intake in the United States: the baseline survey of the Five A Day for Better Health Program. American Journal of Health Promotion 9, 352360.Google Scholar
Sundrum, A (2001) Organic livestock farming. A critical review. Livestock Production Science 67, 207215.Google Scholar
Tauxe, RV (1997) Emerging foodborne diseases: an evolving public health challenge. Emerging Infectious Diseases 3, 425434.CrossRefGoogle ScholarPubMed
Tayabali, AF & Seligy, VL (2000) Human cell exposure assays of Bacillus thuringiensis commercial insecticides: production of Bacillus cereus-like cytolytic effects from outgrowth of spores. Environmental Health Perspectives 108, 919930.Google Scholar
Trewavas, A (2001) Urban myths of organic farming. Nature 410, 409410.Google Scholar
Tschape, H, Prager, R, Streckel, W, Fruth, A, Tietze, E & Bohme, G (1995) Verotoxinogenic Citrobacter freundii associated with severe gastroenteritis and cases of haemolytic uraemic syndrome in a nursery school: green butter as the infection source. Epidemiology and Infection 114, 441450.Google Scholar
Tuffs, A (2002) Organic meat products contaminated with carcinogenic herbicide. British Medical Journal 324, 1416.Google Scholar
Vallance, P (1997) Dietary nitrate: poison or panacea?. Gut 40, 288.Google Scholar
Van Loon, AJ, Botterweck, AA, Goldbohm, RA, Brants, HA, van Klaveren, JD & van den Brandt, PA (1998) Intake of nitrate and nitrite and the risk of gastric cancer: a prospective cohort study. British Journal of Cancer 78, 129135.Google Scholar
Vermeer, IT & van Maanen, JM (2001) Nitrate exposure and the endogenous formation of carcinogenic nitrosamines in humans. Reviews in Environmental Health 16, 105116.Google Scholar
Williams, CM (2002) Nutritional quality of organic food: shades of grey or shades of green?. Proceedings of the Nutrition Society 61, 1924.Google Scholar
Williams, PR & Hammitt, JK (2000) A comparison of organic and conventional fresh produce buyers in the Boston area. Risk Analysis 20, 735746.Google Scholar
Williams, PRHammitt, JK (2001) Perceived risks of conventional and organic produce: pesticides, pathogens, and natural toxins. Risk Analysis 21, 319330.CrossRefGoogle ScholarPubMed
Witter, E (1996) Towards zero accumulation of heavy metals in soils. Fertiliser Research 43, 225233.Google Scholar
Woese, K, Lange, D, Boess, C & Bogl, KW (1997) A comparison of organically and conventionally grown foods – results of a review of the relevant literature. Journal of the Science of Food and Agriculture 74, 281293.Google Scholar
Worthington, V (1998) Effect of agricultural methods on nutritional quality: a comparison of organic with conventional crops. Alternative Therapies in Health and Medicine 4, 5869.Google Scholar
Worthington, V (2001) Nutritional quality of organic versus conventional fruits, vegetables, and grains. Journal of Alternative and Complementary Medicine 7, 161173.Google Scholar
Yussefi, M & Willer, H (2002) Organic Agriculture Worldwide 2002 – Statistics and Future Prospects 4th edition. Bad Durkheim Germany. Foundation Ecology & Agriculture.Google Scholar
Zink, DL (1997) The impact of consumer demands and trends on food processing. Emerging Infectious Diseases 3, 467469.Google Scholar
Zwankhuizen, MJ, Govers, F & Zadoks, JC (1998) Development of potato late blight epidemics: Disease foci, disease gradients, and infection sources. Phytopathology 88, 754763.Google Scholar