Organic foods are healthy: three reasons why

by Ursula Arens, nutrition writer and eco-worrier.

Organic_dt_article_sept_2018Organic foods are now widely available in markets and shops, and they often have one thing in common - a hefty price mark-up compared to conventional produce, leaving consumers often wondering, “is it worth it?”

What should dietitians, the food and science experts, advise? The tags that organic foods claim relate to better health for the consumer, reduced hazards to farm workers, and environmental and ecological benefits (for example, for birds-and-bees in the literal sense.) But there have been challenges to statements that organic foods are healthier, and valid critiques that organic food production is usually less efficient and not the way to feed the growing world population. Claims that organic foods are healthier could relate to either higher content of nutrients or other beneficial components, or to lower levels of contaminants or components known to have adverse health effects. So, are there health benefits from consuming more organic foods?

1. Nutrient differences in organic foods

A literature review by the Soil Association reported that seven studies showed higher amounts of mineral contents and higher vitamin C levels in organic fruit and vegetables compared to conventional products (six studies showed no difference) (1- see references below).

A systematic review in 2009, funded by the Food Standards Authority, assessed the nutritional quality of organic foods; there were no differences compared to conventional products, and any small differences related to seasonal and minor production differences (2). A later systematic review from Stanford University also concluded that nutrient differences in organic foods were small (3). Some studies suggest minor differences in fatty acids in organic meat and milk products, although most of these are likely to be due to effects of grass feeding versus faster growth from the feeding of concentrates (4).

2. Less pesticides/contaminants in organic foods

Foods are regularly tested for pesticides, to ensure that amounts are below the levels assessed as safe for consumption (below Maximum Residue Levels – MRLs). However, consumers may be concerned in relation to individual sensitivities or ‘cocktail’ effects. A meta-analysis by Baranski and colleagues reported that organic crops had higher concentrations of a range of antioxidants such as polyphenolics, had lower frequencies of pesticide residues, and lower levels of cadmium (5). Brandt and colleagues reported greater amounts of ‘biologically active compounds’ in organic fruits and vegetables, and suggest that these benefits could match the health effects of greater intakes of fruit and vegetables (6). The Stanford University review reported lower urinary pesticide levels in children consuming organic produce, and that contamination of detectable pesticide residues on produce was lower (3). Consuming organic foods reduced urinary organophosphate (OP) pesticide metabolites by 90% in a very small sample of Australian adults, although use of OPs is in strong decline (7).

Organic crops had higher concentrations of a range of antioxidants such as polyphenolics.

3. Health effects of organic foods

Several researchers claim measurable health improvements from the consumption of organic foods. Kummeling and colleagues reported lower levels of eczema risk in infants given organic dairy products (8). The Soil Association review reported that several studies found that sperm counts in groups of men consuming organic foods to be higher, than in men consuming conventional foods (1). A study of 325 women undergoing fertility treatments reported that the quartile of women consuming high-pesticide fruits and vegetables had an 18% lower probability of pregnancy and 26% lower probability of a live birth (compared to women in the lowest quartile) (9).

There are many reasons why some people choose organic foods, and it is probable that those who choose organic foods are also those who consider other health and environmental aspects of food choice (10). Organic foods may contain slight nutrient differences and slightly lower risk of pesticide residues, but there are many other reasons to pay a few pennies more for organic produce. 


References

  1. Heaton S. Organic farming, food quality and human health: a review of the evidence. Soil Association publication, 2001
  2. Dangour AD, Dodhia DK, Hayter A, Allen E, Lock K, Uauy R. Nutritional quality of organic foods: a systematic review. Am J Clin Nutr 2009, 90, 680-5
  3. Smith-Spangler C, Brandeau, ML, Hunter GE, Bavinger JC, Pearson M, Eschbach PJ, Sundaram V, Lie H, Schirmer P, Stave C, Olkin I, Bravata DM. Are organic food safer or healthier than conventional alternatives? A systematic review. Ann Intern Med 2012, 157, 5, 348-66
  4. Srednicka-Tober D, Daranski M, Seal C, Sanderson R. Composition differences between organic and conventional meat: a systematic literature review and meta-analysis. Br J of Nutr 2016 115, 6, 994-1011
  5. Baranski M, Srednicka-Tober D, Volakakis N, Seal C. Higher antioxidant and lower cadmium concentrations and lower incidence of pesticide residues in organically grown crops: a systematic literature review and meta-analysis. Br J of Nutr 2014, 112, 5, 794-811
  6. Brandt K, Leifert C, Sanderson R, Seal C. Agroecosystem Management and Nutritional Quality of Plant Foods: The Case of Organic Fruits and Vegetables. Critical Reviews in Plant Sciences 2011, 30, 1-2
  7. Oates L, Cohen M, Braun L, Schembri A, Taskova R. Reduction in urinary organophosphate pesticide metabolites in adults after a weeklong organic diet. Environmental Research 2014, 132, 105-111
  8. Kummeling I, Thijs C, Huber M, Lucy P, Van de Vijver L . Consumption of organic foods and risk of atopic disease during the fi rst 2 years of life in the Netherlands. Br J of Nut 2008, 99, 3, 598-605
  9. Chiu YH, Williams PL, Gillman MW, Gaskins AJ, MinquesAlarcon L, Souter I, Toth TL, Ford JB, Hauser R, Chavarro JE. Association Between Pesticide Residue Intake From Consumption of Fruits and Vegetables and Pregnancy Outcomes Among Women Undergoing Infertility Treatment with Assisted Reproductive Technology. JAMA Intern Med 2018, 178, 1, 17-26
  10. Pelletier JE, Laska MN, Neumark-Sztainer D, Story M. Positive attitudes towards Organic, Local and Sustainable Foods are Associated with Higher Dietary Quality among Young Adults. Journal of the Academy of Nutrition and Dietetics 2013, 113, 1, 127-132