Science in Society Archive

Organic Farms Make Healthy Plants Make Healthy People

Organic foods are richer in minerals and vitamins and relatively free from harmful chemicals and additives. Dr. Eva Novotny

The importance of good food and good soil – a page from history

People in the industrialised Western world rely increasingly on ready-prepared meals and packaged foods.  For increased shelf life, some of the ingredients will have been refined, with the most nutritionally valuable components (such as the germ and bran of grains) discarded, and extra chemicals added as preservative or as flavouring or colour.  At the same time, there is rising incidence of heart disease, cancers, diabetes, allergies and other disorders. Could there be a connection between diet and disease?

The British doctor Sir Robert McCarrison had asked this question 80 years ago while working in India, and his experience was described in a book by GT Wrench first published in 1938, and reprinted twice since [1].  McCarrison was struck by the marvellous health of certain native peoples, especially those living in Hunza, and wondered why that was the case. (A disheartening footnote must be added to the story of the people of Hunza. Already in the 1930s, with increased exposure to Western ways, their remarkable health had begun to decline. )  The natives enjoyed freedom from disease and life-long vitality despite their exceptional longevity.  Their healthy mental state was reflected in their freedom from quarrelling and exceptional cheerfulness. 

The Hunzakuts were an agrarian people, cultivating terraced fields. The numerous small fields were irrigated from a glacier. They enjoyed fresh, nutritious and unprocessed foods, and everything that originated from the soil was returned to the soil. 

Wrench’s book also describes how Sir Albert Howard, Director of the Institute of Plant Industry at Indore , India , followed the ancient Chinese practice of applying manure to crops, which continued to improve as a result.  In the seven years Sir Albert was there, he could not recall a single case of insect or fungous attack.  The animals feeding on these crops also prospered.  He said [2]: “I was able to study the reaction of well-fed animals to epidemic diseases, such as rinderpest, foot-and-mouth disease, septicaemia, and so forth, which frequently devastated the countryside.  None of my animals was segregated; none was inoculated; they frequently came in contact with diseased stock.  No case of infectious disease occurred.  The reward of well-nourished protoplasm was a very high degree of disease resistance, which might even be described as immunity.”

Sir Albert’s method of plant breeding was applied on a farm at Surfleet, England, beginning in 1935, and described a few years later [3]: “ The results of this Surfleet experiment of but two years’ duration have surprised those who have watched it.  The vegetables not only have a richer flavour; not only have they a robuster appearance and their leaves a deeper green; not only do they keep better in storage ...; but in their vegetable health they have attained a new standard.  ...  Howard  ... spoke of the marked improvement in yield and quality of the vegetables, the better tilth and the increased earth-worm population ... .  The most striking feature was the general healthiness of the crops and the absence of insect and fungous pests.  No chemical sprays have to be called into use.  The plants themselves need no such doctoring.”

A well-enriched soil resulted in excellent plant health, which, in turn, produced healthy animals that fed upon well-nourished plants; and human beings whose diet consisted of these fresh and wholesome healthy plants and animal products also enjoyed abundant health.

Direct benefits of organic food

Richer in minerals, vitamins and other nutrients

The mineral content in our food has become severely diminished. Fruits, vegetables and other plants that we rely upon to supply minerals in our diet cannot take adequate amounts of minerals from soil that is deficient in them.  Conventional farming (i.e., intensive farming that uses chemicals) returns little or nothing to the soil and gradually depletes the soil of minerals. As only a small number of nutrients are replenished in chemical fertilisers (especially nitrogen, potassium and phosphorus), the soil gradually loses trace elements essential for health such as boron, chromium and selenium. 

In 1940 and again in 1991, RA McCance and EM Widowson tested various fruits, vegetables (including carrots, broccoli, spinach and potatoes) and meats for mineral content [4].  They found that the amounts of calcium, magnesium, iron and copper in our vegetables had declined during those 51 years by as much as 75 percent or even 96 percent, while meats had lost 41 percent of their calcium and 54 percent of their iron, fruits had lost 27 percent of their zinc, and apples and oranges had lost 67 percent of their iron. The tests were repeated in 2002 with similar results.  It is not only mineral content that has declined over the past half century. Levels of vitamins A and C have also dropped dramatically [5].  Wheat has lost much of its protein since 1900.  Nitrogen fertilisation in conventional farming was found to decrease vitamin C concentrations in many fruits and vegetables [6].  On the other hand, fertilisation of crops with cow dung (as may occur on organic farms) can increase vitamin B12 to a level that may contribute significantly to the diet of vegans [7].  Secondary nutrients also tend to be more abundant in organically grown fruits and vegetables [8].

UK’s Food Standards Agency (FSA) has persistently declared that organic food is no more nourishing than conventional food. But the Soil Association pointed out in its own report [9] that, of the 99 studies on which the FSA based its opinion, only 29 studies were valid and relevant; and even those form a heterogeneous group and cannot be compared properly. Nevertheless, some idea of the relative nutritional properties of organically and non-organically produced food can be obtained, which indicated that, on average, organic food is more nutritious than non-organic food.

The reason that the nutritional content of organic foods is sometimes no higher than that of conventional foods is due partly to the fact that the soil on some organic farms has not had time to recover: regulations require only two years for conversion of land from intensive chemical farming to organic farming.  This time span is insufficient for restoring minerals and other plant nutrients and the microbes necessary for healthy functioning of soil.  Additional factors affecting the results include the influence of the particular cultivars assessed, and conditions of growth and storage.

 Organically reared cows, which eat fresh grass, clover pasture and grass clover silage, produced milk on average 50 percent higher in Vitamin E (alpha tocopherol), 75 percent higher in beta carotene (precursor of Vitamin A) and two to three times higher in the antioxidants lutein and zeaxanthine than non-organic milk [9]. Organic milk not only has more antioxidants but also higher levels of omega 3 essential fatty acids [10].

Medical benefits

A review published in 2001 reported that nitrate levels in organic food are on average 15 percent lower [11], which is important, as scientists at Glasgow University found a link between nitrates in vegetables and gullet cancer, which has trebled over the past 20 years, claiming more than 3000 lives a year. The scientists believed that an increase in the use of nitrate fertilisers since World War II might be one of the main reasons for the rise in this cancer.

A briefing paper from the Soil Association [12] linked health problems as diverse as heart disease, osteoporosis, migraines and hyperactivity to food additives whose use is banned in organic food. A total of 297 additives are permitted in conventional food, while only 27 are allowed in organic food, some of which have to be added for legal reasons.  Among the additives banned in organic food are hydrogenated fat, phosphoric acid, aspartame, monosodium glutamate and sulphur dioxide.

The British Society for Allergy, Environmental and Nutritional Medicine stated [13]: “We have long believed the micronutrient deficiencies common in our patients have their roots in the mineral-depletion of soils by intensive agriculture, and suspect that pesticide exposures are contributing to the alarming rise in allergies and other illnesses.”

A New Zealand boarding school that began serving almost exclusively organically grown produce to its students reported after three years in 1940 [14] that there were “lower incidences of catarrhal conditions, a ‘very marked decline’in colds and influenza, more rapid convalescence, excellent health generally, fewer sports injuries, a greater resilience to fractures and sprains, clear and healthy skin, and improved dental health.”

More recently, doctors and nutritionists administering “alternative” cancer therapies have found that a completely organic diet is essential for a successful outcome [9]. According to the Nutritional Cancer Therapy Trust (NCTT), nutritional cancer therapies that involve the avoidance of pollutants and toxins as much as possible, the exclusive consumption of organically grown foods and increases in nutrient intakes, have yielded good results [15].  The director of NCTT said that [16]  “the overwhelming number of patients following alternative cancer therapies are those who have been declared terminal, with minimal life expectancies following initial allopathic treatment. The ability of these patients to gain remission from all clinical evidence of cancer is therefore very significant.” (Organic strawberries stop cancer cells, this series). 

The USDA reported some 30 years ago [17] that, “the highest death rate areas in the US generally corresponded to those where agriculturists had recognised that the soil was depleted .” Degenerative diseases are prevalent in North America and Europe, in contrast with the absence of these diseases in places that have maintained natural farming methods.

Indirect benefits of organic food

Avoidance of pesticides and antibiotics

Conventional farmers may apply any of more than 350 pesticides [18], while organic farmers are allowed only seven under UK Register of Organic Food Standards (UKROFS), and only four under Soil Association standard [19].These may be applied only if the farmer can justify their use in individual cases. Thus, organic foods very rarely contain chemical residues.   Conventional food, on the other hand, is often found contaminated with harmful residual chemicals.

UK government tests carried out in 2003 found chemical residues in one third of fruits and vegetables, with some containing as many as five different chemicals, some present in amounts exceeding government-set limits [20].  Chemicals applied to the surface of a fruit or vegetable can be partially removed by washing or peeling, but some chemicals enter and permeate the plant or are designed not to wash off in water (rain).  Safety tests do not consider the ‘cocktail effect’ of the many agro-chemicals and food additives that are simultaneously present in the human body. 

Many pesticides are suspected of being endocrine disrupters, affecting sexual characteristics, hormone production or metabolism, thyroid function or brain function [21].   Children are especially susceptible, and later in life, may suffer disorders of behaviour and reproduction and be more prone to disease.  These chemicals affect not only human beings but also other animals.

Human milk has been found tainted with over 350 man-made contaminants including pesticides [22].

In the United States, dairy cows may be injected with a genetically modified growth hormone (rBGH also known as rBST, recombinant bovine somatotropin) to increase milk production.  Canadian and European governments have refused to permit the use of this hormone.  Not only does it increase the incidence of mastitis in cows, but it also increases the incidence of cancer in human beings [23].

The Pesticide Action Network reported [24] that the overall incidence of cancer has risen by about 50 percent since 1971 (Office of National Statistics); and pesticide residues in food may be a contributing factor. International authorities have listed 160 extensively used pesticides as possible human carcinogens.

Antibiotics are not used routinely in organic farms [9] as they are in conventional farms; nor are they often needed.  Better feed and living conditions maintain animals in good health.  When disease does strike, alternative measures such as homeopathy are preferred.  The routine use of antibiotics in conventional livestock may be contributing to the growing antibiotic resistance of pathogens in hospitals.

No genetic modification (GM)

Organic standards forbid certification as organic of any food that has been genetically modified. This restriction, unfortunately, may soon be changed in the European Union to allow contamination of 0.9 percent, as in conventional food.  Transfer of genetic material from one species to another does not occur in nature, as a given species is unable to cross with another.  Forcible transfer of genes in a laboratory, i.e., genetic engineering or genetic modification, entails many hazards to the genetic code of the recipient.  The implantation of a foreign gene into the genetic code of the recipient is random; yet it is now known that the position of a gene is important in determining what effects it will produce.  The old belief, which remains the basis of GM technology, was that there is a one-to-one correspondence between genes and traits.  This belief has been disproved [25] (see Living with the Fluid Genome); yet the GM developers have failed to take heed. In spite of this incomplete understanding of the enormously complex interactions and functioning of genes, GM developers continue to assure the public that their products are safe. But there has been a string of reports indicating that quite the opposite is the case. In India recently, thousands of sheep died after grazing on post-harvest GM cotton fields [26] (Mass Deaths in Sheep Grazing on Bt Cotton, SiS30) , and hundreds of farmers and cotton handlers suffered allergic reactions  [27] ( More illnesses linked to Bt crops, SiS30) In Australia, mice given a diet containing peas that had been modified with a gene from a common bean developed debilitating immune reactions to th e transgenic protein, and the decade-long project of developing the transgenic peas had to be abandoned [28] (Transgenic Pea that Made Mice Ill, SiS29).


To sum up, food produced according to organic principles is superior to that produced by conventional means, i.e., with chemical inputs.  Organic foods are likely to have higher nutritional content, such as vitamins and minerals.  They also rarely contain residues of harmful agricultural chemicals or additives, and for the time being, they exclude GM foods that could damage the immune systems and/or internal organs of experimental animals. 

Article first published 04/09/06


  1. Wrench GT. The Wheel of Health, C.W. Daniel Company Ltd., London; 1938, reprinted 1960 by Lee Foundation for Nutritional Research, Milwaukee, Wisconsin, U.S.A.; reprinted 1990 by Bernard Jensen International, Escondido, California.
  2. Wrench GT (ref. 1), pp.126-7.
  3. Wrench GT (ref.1), pp. 125-7.
  4. McCance RA and Widowson EM, 1940 to 1991, commissioned first by the Medical Research  Council and later by the Ministry of Agriculture, Fisheries and Food, and the Royal Society of Chemistry.
  5. What Doctors Don’t Tell You, Dec. 2002, vol. 13, No. 9, p. 4
  6. Mozafar A. Nitrogen fertilisers and the amount of vitamins in plants: a review. J Plant Nutrition, 1993, 16(12), 2479-506.
  7. Mozafar A. Enrichment of some B-vitamins in plants with application of organic fertilisers. Plant and Soil, 1994, 167, pp. 305-11. 
  8. Brandt K and Mølgaard JP. Organic agriculture: does it enhance or reduce the nutritional value of plant foods? J Sci of Food and Agric, 2001, 81, pp. 924-931.
  9. Heaton S. Organic Farming, Food Quality and Human Health, Soil Association, Bristol, 2001.
  10. “New research proves organic milk is higher in vitamins and antioxidants than non-organic milk”, Soil Association, Press Release 03/02/2005, citing a number of scientific papers.
  11. Worthington V. Nutritional Quality of Organic Versus Conventional Fruits, Vegetables and Grains. J Altern  and Complem Medicine, 2001, 7, No. 2, pp.161-173.
  12. Nutritional benefits of organic food. Soil Association Briefing Paper, 8 September 2003, Soil.
  13. Heaton S. (ref. 9), back cover.
  14. Daldy Y. Food production without artificial fertilisers. Nature, 1940, 145(3684), 905-6.
  15. Plaskett LG. Clinical application of a nutritional cancer therapy with prescribed diet and nutrients. The Nutritional Cancer Therapy Trust, Surrey, UK, 2000.
  16. Ashton, C, Director of the Nutritional Cancer Therapy Trust, personal communication in April 2001 to S Heaton (ref. 9).
  17. USDA Agricultural Research Services Report No. 2, 'Evaluation of Research in US on Human Nutrition', 1971, cited in Heaton S. Organic Farming, Food Quality and Human Health, p.11, Soil Association, Bristol, 2001.
  18. Inputs in Organic Farming. Soil Association Information Sheet. 06/10/2005 (version 5).
  19. Soil Association (ref. 18); and Soil Association. Plant Protection Products allowed under Soil Association and UKROFS Standards for Organic Farming in the UK, 26 April 2003.
  20. Pesticide Residues Committee, Annual Report of the Pesticide Residues Committee, 2003.
  21. Gwynne Lyons. Endocrine disrupting pesticides. Pesticide News, Dec. 1999, No. 46, pp. 16-19.
  22. WWF. Chemical Trespass -- A Toxic Legacy. 1999.
  23. George Monbiot, 2000, Captive State: the Corporate Takeover of Britain, Macmillan, London.
  24. Alison Craig, Pesticide Action Network, Letters, 19 August 2001.
  25. Ho MW. Living with the Fluid Genome, TWN and ISIS, Penang and London, 2003,
  26. Ho MW. Mass death in sheep grazing on Bt cotton. Science in Society 2006, 30, 12-13.
  27. Ho MW. More illnesses linked to Bt crops. Science in Society 2006, 30, 8-9,
  28. Ho MW. Transgenic pea that make mice ill. Science in Society 2006, 29, 28-29.

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