Organic farming is a sustainable farming system which emphasizes developing healthy fertile soil, rich in microorganisms and natural minerals, maintained by rotating a mixture of crops, with minimal use of chemical fertilizers or pesticides.
Advocates for organic produce claim that it contains fewer harmful chemicals, is more nutritious, and is better for the environment.
A review by Smith-Spangler et al (2012) found little evidence for increased nutritional value in organic foods though a number of studies suggested that organic milk may contain significantly higher levels of omega-3 fatty acids. Also a 33% greater risk of antibiotic-resistant bacteria was found in non-organic pork and chicken.
With regard to the ingestion of toxins this study did however conclude that conventional produce carries a 30% higher chance of pesticide contamination when compared with organic foods. Previous studies have found lower levels of pesticides in the urine of children who eat organic vegetables (Lu et al 2005). This confirms, I believe, that eating organic is a healthier option. Pesticides are implicated in many chronic diseases.
For instance women who have breast cancer are 5-9 times more likely to have pesticide residues in their blood than women who do not (Charlier et al 2003).
The risk of breast cancer was assessed prospectively in a group of over 7,000 women of whom 268 developed the disease and a correlation with xeno-oestrogens was found (Hoyer et al 1998).
A study of 45 different pesticides in relation to over 55,000 male agricultural workers revealed a significant link between the use of organochlorine pesticides and prostate cancer (Alavanja et al 2003).
A link has been found between a decline in male reproductive health and environmental oestrogens (Sharpe and Skakkeback 1993). On the other hand men who ate organic food were found to have significantly higher sperm counts than men on conventional diets (Jensen et al 1996).
Sperm density was found to be much higher amongst a group of organic farmers than in other workers (Abell et al 1994).
Obesity is a growing problem and synthetic chemicals are used to increase weight in animals and it may be that these Endocrine Disrupting Chemicals (EDCs) influence obesity by interfering with weight controlling mechanisms in people (Baillie -Hamilton 2003).
How to reduce your grocery bill safely
Not all produce is equal. There are some foods which are found to contain greater concentrations or more toxic pesticides than others and being aware of this can make us savvy shoppers. The Environmental Working Group, a non profit making environmental research organization, has published a list of the Dirty Dozen and the Clean Fifteen which we can use as a guide as to the most important fruit and vegetables to buy organic. According to EWG by eating some of the most contaminated fruit and veg you are being exposed to about 10 different pesticides per day. By choosing the least contaminated produce you can limit this to 2 per day.
The Dirty Dozen (or so) – Buy organic
The Clean Fifteen – Buy conventional
Sweet peas (Mange tout)
It has to be said, however, that as fruit and vegetables confer so many benefits It is better to consume your 5, or better still 9, portions of fruit and veg a day as non organic produce than not at all.
Abell A., Ernst E., Bonde J.P., (1994), High sperm density among members of organic farmers’ association. Lancet 343:1498
Alavanja M .C.R., Samanic C., Dosemeci M., Lubin J., Tarone R., Lynch C.F., Knott C., Thomas K., Hoppin J.A., Barker J., Coble J., Sandler D.P., Blair A.,(2003), Use of agricultural pesticides and prostate cancer risk in the agricultural health study cohort. American Journal of Epidemiology 157:800-814
Baillie-Hamilton P.F., Chemical Toxins: A Hypothesis to Explain the Global Obesity Epidemic. The Journal of Alternative and Complementary Medicine 8(2): 185-192
Charlier C., Alber A., Herman P., Hamoir E., Gaspard U., Meurisse M., Plomteux G.,(2003) Breast cancer and serum organochlorine residues. Occupational and Environmental Medicine 60:348-351
Hoyer A.P., Grandjean P., Jorgensen T., Brock J.W., Harwig J.B., (1998), Organochlorine exposure and the risk of breast cancer. Lancet 352(9143):1816-20
Jensen T.K., Giwercman A., Carlsen E., Scheike T., Skakkebaek N.E., (1996) Lancet 347:1844
Lu C Toepel K Irish R Fenske RA Barr DB Bravo R (2005) Organic diets significantly lower children’s dietary exposure to organophosphorus pesticides Environmental Health Perspectives 114(2) 260-263
Smith-Sprangler C Brandeau ML Hunter GE Bavinger JC Pearson M Eschback PJ Sundaram V Liu H Schirmer P Stave C Olkin I Bravata DM (2012) Are organic foods safer or healthier than conventional alternatives?: a systematic review Annals of Internal Medicine 157(5)348-366
Environmental Working Group (2012) (online) Last accessed 7.11.12 at http://www.ewg.org/foodnews/
Sharpe R.M., and Skakkeback N.E. (1993), Are oestrogens involved in falling sperm counts and disorders of the male reproductive tract? Lancet 341:1392-1395