Science in Society Archive

Organics for Health

A Chapter from the Independent Science Report, The Case for a GM-Free Sustainable World

Here’s some of the evidence that Sir John Krebs, Head of UK’s Food Standards Agency refuses to acknowledge in his persistent denigration of organic agriculture.

Less chemical residues

A comprehensive Soil Association review of scientific research has shown that, on average, organic food is better for us than non-organic food [1]. First, it is safer, as organic farming prohibits routine pesticide and herbicide use, so chemical residues are rarely found. In contrast, non-organic food is likely to be contaminated with residues that often occur in potentially dangerous combinations. The British Society for Allergy, Environmental and Nutritional Medicine states on the back cover of the report: "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" (italics added).

The negative effects of pesticides on health include neurotoxicity, disruption of the endocrine system, carcinogenicity and immune system suppression. The impacts of dietary exposure to pesticide residues at levels typically found in and on food are less easy to establish, but a precautionary approach is necessary. While there are recommended safety levels for pesticides, the UK government’s own tests have shown that average residue levels on foods may be under-reported.

Research has also suggested that pesticide exposure affects male reproductive function, resulting in decreased fertilising ability of the sperm and reduced fertilisation rates [2]. Correspondingly, members of a Danish organic farmers’ association, whose intake of organic dairy products was at least 50% of total intake of dairy products, had high sperm density [3]. In another study, sperm concentration was 43.1% higher among men eating organically produced food [4].

Children, in particular, may stand to benefit from organic food. Scientists monitored preschool children in Seattle, Washington to assess their exposure to organophosphorus (OP) pesticide from diet [5]. The total dimethyl metabolite concentration was approximately six times higher for children with conventional diets than those with organic diets. The calculated dose estimates suggest that consumption of organic fruits, vegetables and juice can reduce children’s exposure levels from above to below the US Environmental Protection Agency’s guidelines, thereby shifting exposures from a range of uncertain risk to a range of negligible risk. The study concluded that consumption of organic produce could be a relatively simple way for parents to reduce children’s exposure to OP pesticides.

Healthier and more nutritious

Additionally, organic food production bans the use of artificial food additives such as hydrogenated fats, phosphoric acid, aspartame and monosodium glutamate, which have been linked to health problems as diverse as heart disease, osteoporosis, migraines and hyperactivity [1].

Furthermore, while plants extract a wide range of minerals from the soil, artificial fertilisers replace only a few principal minerals. There is a clear long-term decline in the trace mineral content of fruit and vegetables, and the influence of farming practices needs to be investigated more thoroughly. The Soil Association review [1] found that on average, organic food has higher vitamin C, higher mineral levels and higher phytonutrients – plant compounds that can fight cancer (see later) – than conventional food.

Conventional produce also tends to contain more water than organic produce, which contains more dry matter (on average, 20% more) for a given total weight [1]. Thus, the higher cost of fresh organic produce is partly offset by purchasers of conventional produce paying for the extra weight of water and getting only 83% of the nutrients, on average, available in organic produce. The higher water content also tends to dilute nutrient content.

Tests with people and animals eating organic food show it makes a real difference to health, and alternative cancer therapies have achieved good results relying on the exclusive consumption of organic food. The review [1] cites recent clinical evidence from doctors and nutritionists administering "alternative" cancer treatments, who have observed that a completely organic diet is essential for a successful outcome. Nutritional cancer therapies avoid pollutants and toxins as much as possible, and promote exclusive consumption of organically grown foods and increases in nutrient intakes. Animal feeding trials have also demonstrated better reproductive health, better growth, and better recovery from illness.

A literature review of 41 studies and 1 240 comparisons [6] found statistically significant differences in the nutrient content of organic and conventional crops. This was attributed primarily to differences in soil fertility management and its effects on soil ecology and plant metabolism. Organic crops contained significantly more nutrients -vitamin C, iron, magnesium and phosphorus - and significantly less nitrates (a toxic compound) than conventional crops. There were non-significant trends showing less protein in organic crops. However, organic crops were of a better quality and had higher content of nutritionally significant minerals, with lower amounts of some heavy metals compared to conventional ones.

Helping fight cancer

Plant phenolics (flavonoids) are plant secondary metabolites thought to protect plants against insect predation, bacterial and fungal infection and photo-oxidation. These plant chemicals have been found to be effective in preventing cancer and heart disease, and to combat age-related neurological dysfunctions. A recent scientific paper [7, 8] compared the total phenolic (TP) content of marionberries, strawberries and corn grown by organic and other sustainable methods with conventional agricultural practices. Statistically higher levels of TPs were consistently found in organically and sustainably grown foods as compared to those produced by conventional agriculture.

An earlier study comparing antioxidant compounds in organic and conventional peaches and pears established that an improvement in the antioxidant defence system of the plants occurred as a consequence of organic cultivation practices [9]. This is likely to exert protection against fruit damage when grown in the absence of pesticides. Hence organic agriculture, which eliminates the routine use of synthetic pesticides and chemical fertilisers, could create conditions favourable to the production of health-enhancing plant phenolics.

These and many other health benefits of organic foods have been brought to the attention of the UK government [10, 11]. Among the issues raised are the hidden costs of conventional agriculture, which are not factored into the price. If hidden costs were taken into account, conventionally produced food would prove more expensive than organic food. For example, avoidance of the BSE epidemic through organic farming would have saved £4.5 billion. No animal born and raised on an organic farm developed BSE in the UK.

Article first published 04/07/03


  1. Heaton S. Organic farming, food quality and human health: A review of the evidence, Bristol: Soil Association 2001.
  2. Tielemans E, van Kooij E, te Velde ER, Burdorf A and Heederik D. ‘Pesticide exposure and decreased fertilisation rates in vitro’, The Lancet 1999, 354, 484-485.
  3. Abell A, Ersnt E and Bonde JP. ‘High sperm density among members of organic farmers’ association’, The Lancet 1994, 343, 1498.
  4. Jensen TK, Giwercman A, Carlsen E, Scheike T and Skakkebaek NE. ‘Semen quality among members of organic food associations in Zealand, Denmark’, The Lancet 1996, 347, 1844.
  5. Curl CL, Fenske RA and Elgethun K. ‘Organophosphorus pesticide exposure of urban and suburban preschool children with organic and conventional diets’, Environmental Health Perspectives 2003, 111(3), 377-382.
  6. Worthington V. ‘Nutritional quality of organic versus conventional fruits, vegetables, and grains’, The Journal of Alternative and Complementary Medicine 2001, 7(2), 161–173.
  7. Asami DK, Hong YJ, Barrett DM and Mitchell AE. 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, J. Agric. Food Chem. 2003, 51(5), 1237-1241, 10.1021/jf020635c S0021-8561.
  8. Cummins J. ‘ Organic agriculture helps fight cancer ’, ISIS Report 27 March 2003; also Science in Society Spring 2003, 18 , 18
  9. Carbonaro M, Mattera M, Nicoli S, Bergamo P and Cappelloni M. ‘Modulation of antioxidant compounds in organic vs conventional fruit (Peach, Prunus persica L., and Pear, Pyrus communis L.), J. Agric. Food Chem. 2002, 50, 5458-5462.
  10. Novotny E. ‘Report IV - The Wheel of Health’ (in the Chardon LL T25 maize hearing listings) 2002,
  11. Novotny E. Letter to MSPs on the Organic Farming Targets Bill, 2003,

Got something to say about this page? Comment

Comment on this article

Comments may be published. All comments are moderated. Name and email details are required.

Email address:
Your comments:
Anti spam question:
How many legs on a duck?