Organic food is renowned for its array of health and environmental benefits. According to the 2021 Australian Organic Market Report, ‘chemical-free’, ‘additive-free’ and ‘non-GMO’ were some of the top perceived benefits of organic food by Australian shoppers[1].
The combination of fertile, carbon-rich soil and an absence of chemical fertilisers and synthetic pesticides appears to be a winning combination for yielding healthy and flavourful produce.
Research is increasingly supporting the notion that the food we eat influences composition and function of the human gut microbiome, and in turn overall human health. Organic farming and produce have multiple health benefits for agricultural workers and consumers alike. Organic systems rely on soil that is rich in organic matter and microbial life; this produces robust plants that have minimal requirements for other inputs and are nutritious for you and your family.
Nutrient density and benefits
Research has shown certified organic foods can be more nutritionally dense than their non-organic counterparts, delivering more essential nutrients per calorie consumed. Organic foods have also been shown to contain reduced heavy metals and pesticides[1], with increased antioxidant activity, carotenoids, phenolics and flavonoids as compared to non-organic foods. Organics have also been noted to contain more polyunsaturated fats and omega-3 fatty acids, micronutrients, protein and other non-essential amino acids[2].
Below are some of the benefits of the nutritional density described, but this is by no means an exhaustive list:
- Organic polyphenols and antioxidants are linked to the prevention of cardiovascular disease, cancer, and osteoporosis[41]
- Carotenoids are important for beneficial bacterial colonisation[3]
- Flavonoids inhibit the growth of various pathogens while promoting beneficial genera Bifidobacterium and Lactobacillus[4]
- Antioxidant activity removes potentially damaging oxidising agents[5]
- Phenolics may positively alter microbiome composition through prebiotic and antimicrobial effects against pathogens[6]
- Polyunsaturated fatty acids positively affect microbiota composition in instances of inflammatory bowel disease[7]
Minimal inputs
Chemical Pesticides
A 2019 survey in the USA found that 86 per cent of 1,800 organic farmers questioned switched to organic because of health concerns for themselves and their family[8]. And for good reason!
Many of the pesticides detected in non-organic foods are toxic, carcinogenic[9], neurotoxic or confirmed endocrine-disrupting chemicals[10] and can negatively affect human health even at very low concentrations[11].
The toxicity of a given pesticide depends on a host of factors, including the dose and duration of exposure, the synergistic interactions with other chemicals and route of exposure (inhalation, skin, ingestion, etc.). Pesticides, like heavy metals, can bioaccumulate (increase in concentration)[12].
Children possess a unique susceptibility to toxic chemicals because they drink more liquids, breathe more air and consume more food per pound of body weight than adults. This also makes them more vulnerable to environmental toxins such as pesticides, potentially causing severe long-lasting damage[13]. Pesticide exposure during pregnancy has well documented in-utero deleterious effects including pre-term birth[14], neurodevelopmental delays, male reproductive developmental and genital problems[15], developmental neurotoxicity and ASD (autism spectrum disorder)[16].
Glyphosate, a commonly used herbicide, has been shown to decrease sperm quantity and quality in rats[17] and humans[18], can induce transgenerational inheritance of disease and mutations, and is a suspected carcinogen[19]. More information regarding the potentially dangerous effects of pesticides on human health can be found in Table 1 below.
Synthetic Fertilisers
Synthetic fertilisers are commonly referred to as NPK (nitrogen-phosphorus-potassium) fertilisers, which refers to the concentration of each macro-nutrient. In addition to the negative potential impacts of synthetic fertilisers leaching into the environment, they can also destroy the soil microbiome with multiple ramifications[20].
Mineral nitrogen fertiliser is associated with a reduction in crop resilience, lowering concentrations of nutritionally desirable phenolics and other beneficial natural resistance-related phytochemical and antioxidants in crops[21]. This in turn increases insect and disease susceptibility of plants, exacerbating the need for pesticide intervention[22]. Plants that grow in overly synthetic-fertilised soil have been shown to be deficient in iron, zinc, carotene, vitamin C, copper and protein[23].
Non-organic application of water-soluble mineral-P fertiliser has been shown to increase the concentration of toxic metal cadmium (Cd) in crop plants[24]. All phosphorus fertilisers contain Cd as a contaminant and levels may vary from trace amounts to as much as 300mg Cd per kg of dry product[25]. Cadmium and heavy metals indirectly affect rhizosphere chemistry, soil microbial activity, soil pH, zinc concentration and plant growth[26]. Heavy metals can cause perturbations of the gut microbiota[27] and contribute to the progression of various metabolic diseases[28].
Organic systems have high nutrient use efficiency and crop rotations to increase soil fertility through natural means. Organic cereals have been shown to have higher antioxidants and lower cadmium concentrations[29], with significant decreases in cadmium also found in wheat, potatoes, onion, lettuce and cabbage within organic compared to non-organic systems[30].
Antibiotics and Growth Regulators
Over 700,000 people die annually from antibiotic resistant bacteria. This transfer of resistance is largely attributed to antibiotic residues in non-organic meat and milk[31]. Currently, over 75% of the world’s antibiotics are used for non-organic livestock production[32]. In addition to the risks of antibiotic resistance, hormone growth promoters (HGPs) are used to make animals grow faster and mature earlier. HGPs within livestock have been linked to increased cancer rates[33]. A study on Chlormequat Chloride, a common non-organic growth regulator and suspected endocrine disruptor, was also linked to reduced fertility in animals including breeding sows[34].
GMOs
To date, there have been no long-term epidemiological studies investigating potential impacts of GMO food on human health. However, there are many animal studies linking GMOs with innumerable negative effects on organs, the reproductive systems, induced blood, hormonal and immunological alterations, toxicity in multiple organs as well as increased tumours and mortality[35][36][37]. Many studies show signs of toxicity in the liver and kidney, the major detoxifying organs. These organs are often the first to show evidence of chronic disease[38], however, these effects are commonly disregarded as biologically insignificant when they don’t cause animal mortality. Most animal feeding studies on GMOs are short to medium-term in length, too brief to show long-term (chronic) effects such as organ failure, cancer, or reproductive problems. For more, have a read of our article on GMOs and Agriculture.
Minimal Inputs
Synthetic chemicals, unnatural flavours, colours, preservatives and food additives are restricted or prohibited in organic food. As various food additives and chemicals are linked to symptoms including allergic reactions, rashes, headaches, asthma, neurodevelopment problems and hyperactivity in children, organic food provides a safe alternative for those concerned about their general health.
Why Organic?
Multiple meta-analyses of organic versus non-organic crop production concluded certified organic food consumption reduces dietary exposure to pesticides and the associated health risks[39][40].
Maximum Residue Limits (MRLs) are the highest amount of an agricultural or veterinary chemical residue that is legally allowed in a food product. Within Australia, MRLs are overseen by Food Standards Australia (FSANZ). Certified organic product MRLs are 10% or less of that allowed within FSANZ. This means that almost all the 900+ chemicals approved for use in non-organic agriculture in Australia are not allowed for use within certified organic production systems. These include, but are not limited to, antibiotics and synthetic pesticides including herbicides, insecticides, fungicides, growth regulators, organophosphates, and pyrethroids. These chemicals, especially broad-spectrum products, have a myriad of potential side effects when consumed through non-organic food.
Conclusion
Selecting organic foods means you can minimise your risk of exposure to toxic pesticides and veterinary medicines in food. Organic produce may be more nutrient dense and help contribute to a more balanced and healthier lifestyle. Remember to look for an organic certification mark such as the Australian Certified Organic Bud logo to ensure you are purchasing legitimately organic food.
For further reading, please see a selection of the peer reviewed articles below.
Table 1. Associated peer reviewed research findings of human exposure to common agricultural pesticides
| Title | Year | Key Findings | Available at: |
| Organic Diets Significantly Lower Children’s Exposure to Organophosphorus Pesticides. | 2006 | Researchers measured the dietary exposure to pesticides of 23 elementary school children by taking urine samples taken twice daily and measuring concentrations of malathion and chlorpyrifos pesticide metabolites. The metabolites (chemicals created as the body breaks down pesticides) immediately decreased to non-detectable levels after children switched to an organic diet and remained undetectable until non-organic diets resumed. | See Link |
| Fruit and vegetable intake and their pesticide residues in relation to semen quality among men from a fertility clinic. | 2019 | A study of 155 men and 338 semen samples showed that those who ate more fruits and vegetables with high levels of pesticide residues had 49% lower sperm counts and a 32% lower percentage of normal sperm than men who ate less fruit per day. The men with lower sperm counts also had lower ejaculate volumes and lower percentages of normal sperm. | See Link |
| Association Between Pesticide Residue Intake from Consumption of Fruits and Vegetables and Pregnancy Outcomes Among Women Undergoing Infertility Treatment With Assisted Reproductive Technology. | 2019 | Researchers tracked 325 women for two years, who regularly ate high or low levels of pesticide-treated fruits and vegetables while undergoing in vitro fertilisation, to assess the association between pesticide residues in produce and infertility treatment success. They found that the women experienced a lower probability of getting pregnant with in vitro fertilisation when they consumed greater amounts of produce with high pesticide residues. | See Link |
| Neurodevelopmental disorders and prenatal residential proximity to agricultural pesticides: the CHARGE study. | 2014 | A study of 970 female participants was conducted over 11 years where commercial pesticide application data and residential proximity were monitored during pregnancy. The study showed exposure to agricultural pesticides during pregnancy can trigger developmental neurotoxicity and has been linked to childhood autism. | See Link |
| Widely Used Pesticide in Food Production Damages Children’s Brains. | 2019 | During pregnancy, even low levels of exposure to pesticides such as chlorpyrifos (an APVMA registered insecticide) can impair learning, change brain function and alter thyroid levels of offspring into adulthood. | See Link |
| Prenatal exposure to the organophosphate pesticide chlorpyrifos and childhood tremor. | 2015 | Chlorpyrifos (an APVMA registered insecticide) has been linked with a decrease in psychomotor and mental development in three-year-old children. | See Link |
| Agricultural pesticide use and adverse birth outcomes in the San Joaquin Valley of California. | 2017 | A review of 500,000 births in the San Jose Valley California was conducted over 15 years. The top 1% of women exposed to pesticides led to an 11% increased probability of preterm birth, 20% increased probability of low birth weight, and ~30 g decrease in birth weight. | See Link |
| Impaired Reproductive Development in Sons of Women Occupationally Exposed to Pesticides during Pregnancy. | 2008 | The study was completed on 113 mother-son pairs who were categorised dependent on pesticide exposure. Boys of pesticide-exposed mothers showed decreased penile length, testicular volume, serum concentrations of testosterone, and inhibin B. Pesticide exposure during pregnancy causes adverse effects on the reproductive development in the male infants. | See Link |
| Attention-deficit/hyperactivity disorder and urinary metabolites of organophosphate pesticides. | 2010 | The study examined the levels of pesticide residue in the urine of more than 1,100 children ages 8 to 15 and found that those with the highest levels of dialkyl phosphates, which are the breakdown products of organophosphate pesticides, had the highest incidence of ADHD. Overall, they found a 35% increase in the odds of developing ADHD with every tenfold increase in urinary concentration of the pesticide residue. | See Link |
Further Reading
[1] Rempelos, L., Baranski, M., Wang, J., Adams, T. N., Adebusuyi, K., Beckman, J. J., … & Leifert, C. (2021). Integrated Soil and Crop Management in Organic Agriculture: A Logical Framework to Ensure Food Quality and Human Health?. Agronomy, 11(12), 2494.
[2] Ranadheera, S., Gardner Lee, S.,Wittwer, A., University of Melbourne. (2021). How Do Organic and Non-Organic Foods Influence Our Gut Microbiome? Available at: https://pursuit.unimelb.edu.au/articles/how-do-organic-and-non-organic-foods-influence-our-gut-microbiome.
[3] Dingeo, G., Brito, A., Samouda, H., Iddir, M., La Frano, M., & Bohn, T. (2020). Phytochemicals as modifiers of gut microbial communities. Food & Function.
Pei, R., Liu, X., & Bolling, B. (2020). Flavonoids and gut health. Current opinion in biotechnology, 61, 153-159.
[4] Lyu, Y., Wu, L., Wang, F., Shen, X., & Lin, D. (2018). Carotenoid supplementation and retinoic acid in immunoglobulin A regulation of the gut microbiota dysbiosis. Experimental Biology and Medicine, 243(7), 613-620.
[5] Griffiths, K., Aggarwal, B. B., Singh, R. B., Buttar, H. S., Wilson, D., & De Meester, F. (2016). Food antioxidants and their anti-inflammatory properties: a potential role in cardiovascular diseases and cancer prevention. Diseases, 4(3), 28.
[6] Kumar Singh, A., Cabral, C., Kumar, R., Ganguly, R., Kumar Rana, H., Gupta, A., … & Pandey, A. K. (2019). Beneficial effects of dietary polyphenols on gut microbiota and strategies to improve delivery efficiency. Nutrients, 11(9), 2216.
[7] Costantini, L., Molinari, R., Farinon, B., & Merendino, N. (2017). Impact of omega-3 fatty acids on the gut microbiota. International journal of molecular sciences, 18(12), 2645.
[8] Oregon Tilth and Oregon State University’s Center for Small Farms & Community Food Systems. “Breaking New Ground: Farmer Perspectives on Organic Transition.” Oregon Tilth, 2017. Retrieved July 11, 2019, from https://tilth.org/education/resources/breakingground/.
[9] Guyton, K.Z.; Loomis, D.; Grosse, Y.; El Ghissassi, F.; Benbrahim-Tallaa, L.; Guha, N.; Scoccianti, C.; Mattock, H.; Straif, K. Carcinogenicity of tetrachlorvinphos, parathion, malathion, diazinon, and glyphosate. Lancet Oncol. 2017, 16, 490–491.
[10] Mnif, W.; Ibn Hadj Hassine, A.; Bouaziz, A.; Bartegi, A.; Thomas, O.; Roig, B. Effect of Endocrine Disruptor Pesticides: A Review. Int. J. Environ. Res. Public Health 2011, 8, 2265–2303.
[11] Rempelos, L., Wang, J., Barański, M., Watson, A., Volakakis, N., Hoppe, H. W., … & Leifert, C. (2022). Diet and food type affect urinary pesticide residue excretion profiles in healthy individuals: results of a randomized controlled dietary intervention trial. The American journal of clinical nutrition, 115(2), 364-377.
[12] Environmental Working Group. “Triple play: EWG posts ‘Dirty Dozen’ list of fresh produce items.” Food Safety News, April 10, 2018. Available at: https://www.foodsafetynews.com/2018/04/triple-play-ewg-posts-dirty-dozen-list-of-fresh-produce-items/.
[13] Committee on Pesticides in the Diets of Infants and Children. “Pesticides in the Diets of Infants and Children.” National Academy Press: Washington, DC. 1993. Retrieved July 11, 2019, from https://www.nap.edu/read/2126/chapter/1#xi.
[14] Larsen, Ashley E et al. “Agricultural pesticide use and adverse birth outcomes in the San Joaquin Valley of California.” Nature Communications, 8, 302 (2017). Available at: https://www.nature.com/articles/s41467-017-00349-2.
[15] Anderson, Helle R. et al. “Impaired Reproductive Development in Sons of Women Occupationally Exposed to Pesticides during Pregnancy.” Environmental Health Perspectives, 116(4): 566-572 (April 2008). Retrieved July 11, 2019, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2290975/.
[16] Shelton, JF et al. “Neurodevelopmental disorders and prenatal residential proximity to agricultural pesticides: the CHARGE study.” Environmental Health Perspectives, 122(1): 1103-9 (October 2014). Retrieved July 11, 2019, from https://www.ncbi.nlm.nih.gov/pubmed/24954055.
[17] Liu, J. B., Li, Z. F., Lu, L., Wang, Z. Y., & Wang, L. (2022). Glyphosate damages blood-testis barrier via NOX1-triggered oxidative stress in rats: Long-term exposure as a potential risk for male reproductive health. Environment international, 159, 107038.
[18] Chiu, Yu-Han et al. “Fruit and vegetable intake and their pesticide residues in relation to semen quality among men from a fertility clinic.” Human Reproduction, 30(6): 1342-51 (June 2015). Retrieved July 11, 2019, from https://www.ncbi.nlm.nih.gov/pubmed/25824023.
[19] Kubsad, D., Nilsson, E.E., King, S.E. et al. Assessment of Glyphosate Induced Epigenetic Transgenerational Inheritance of Pathologies and Sperm Epimutations: Generational Toxicology. Sci Rep 9, 6372 (2019). https://doi.org/10.1038/s41598-019-42860-0.
[20] Tripathi, S., Srivastava, P., Devi, R. S., & Bhadouria, R. (2020). Influence of synthetic fertilizers and pesticides on soil health and soil microbiology. In Agrochemicals Detection, Treatment and Remediation (pp. 25-54). Butterworth-Heinemann.
[21] Rempelos, L., Baranski, M., Wang, J., Adams, T. N., Adebusuyi, K., Beckman, J. J., … & Leifert, C. (2021). Integrated Soil and Crop Management in Organic Agriculture: A Logical Framework to Ensure Food Quality and Human Health? Agronomy, 11(12), 2494.
[22] Ghosh, N. (2004). Reducing dependence on chemical fertilizers and its financial implications for farmers in India. Ecological Economics, 49(2), 149-162.
[23] Sabry, A. K. (2015). Synthetic fertilizers; role and hazards. Fertilizer Technology, 1, 110-133.
[24] Dharma-wardana, M.W.C. Fertilizer usage and cadmium in soils, crops and food. Environ. Geochem. Health 2018, 40, 2739–2759.
[25] Grant, C.A.; Sheppard, S.C. Fertilizer impacts on cadmium availability in agricultural soils and Crops. Hum. Ecol. Risk Assess. 2008, 14, 210–228.
[26] Cooper, J.; Sanderson, R.; Cakmak, I.; Ozturk, L.; Shotton, P.; Carmichael, A.; Sadrabadi Haghighi, R.; Tetard-Jones, C.; Volakakis, N.; Eyre, M.; et al. Effect of organic and conventional crop rotation, fertilization and crop protection practices on metal contentsin wheat (Triticum aestivum). J. Agric. Food Chem. 2011, 59, 4715–4724.
[27] Shao, M., & Zhu, Y. (2020). Long-term metal exposure changes gut microbiota of residents surrounding a mining and smelting area. Scientific reports, 10(1), 1-9.
[28] Duan H, Yu L, Tian F, Zhai Q, Fan L, Chen W. Gut microbiota: A target for heavy metal toxicity and a probiotic protective strategy. Sci Total Environ. 2020 Nov 10;742:140429. doi: 10.1016/j.scitotenv.2020.140429. Epub 2020 Jun 25. PMID: 32629250.
[29] Baranski, M.; ´Srednicka-Tober, D.; Volakakis, N.; Seal, C.; Sanderson, R.; Stewart, G.B.; Benbrook, C.; Biavati, B.; Markellou, E.; Giotis, H.; et al. 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. Nutr. 2014, 112, 794–811.
[30] Rempelos, L., Baranski, M., Wang, J., Adams, T. N., Adebusuyi, K., Beckman, J. J., … & Leifert, C. (2021). Integrated Soil and Crop Management in Organic Agriculture: A Logical Framework to Ensure Food Quality and Human Health?. Agronomy, 11(12), 2494.
[31] Animals Australia. (2020). Available at: https://animalsaustralia.org/latest-news/deep-dive-antibiotics/.
[32] Van Boeckel, T.P., Glennon, E.E., Chen, D., Gilbert, M., Robinson, T.P., Grenfell, B.T., Levin, S.A., Bonhoeffer, S. and Laxminarayan, R., 2017. Reducing antimicrobial use in food animals. Science, 357(6358), pp.1350-1352.
[33] Nunan, C. (2020). Farm Antibiotics and Trade Deals. Alliance to Save Our Antibiotics. Available at: https://www.saveourantibiotics.org/media/1864/farm-antibiotics-and-trade-could-uk-standards-be-undermined-asoa-nov-2020.pdf.
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[37] Hines FA. Memorandum to Linda Kahl on the Flavr Savr tomato (Pathology Review PR–152; FDA Number FMF– 000526): Pathology Branch’s evaluation of rats with stomach lesions from three four-week oral (gavage) toxicity studies (IRDC Study Nos. 677–002, 677–004, and 677–005) and an Expert Panel’s report. US Department of Health &Human Services; 1993. Available at: http://www.biointegrity.org/FDAdocs/17/view1.html.
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[39] Smith-Spangler, C.; Brandeau, M.L.; Hunter, G.E.; Clay Bavinger, J.; Pearson, M.; Eschbach, P.J.; Sundaram, V.; Liu, H.; Schirmer, P.; Stave, C.; et al. Are organic foods safer or healthier than conventional alternatives? A systematic review. Ann. Intern. Med.2012, 157, 348–366.
[40] Mie, A.; Andersen, H.R.; Gunnarsson, S.; Kahl, J.; Kesse-Guyot, E.; Rembiałkowska, E.; Quaglio, G.; Grandjean, P. Human health implications of organic food and organic agriculture: A comprehensive review. Environ. Health 2017, 16, 111.
[41] Pandey, K; Rizvi, S; Plant polyphenols as dietary antioxidants in human health and disease, Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2835915/.