This post was written by one of our contributors; dietitian – Maeve Hanan
Sales of organic food are on the rise – despite the fact that this can be up to 200% more expensive than non-organic food! (1, 2). But is the choice to go organic backed by good evidence, and even so, is it worth this extra cost?
What is Organic Food?
Food can be certified as organic if it meets a specific set of criteria, which differs between countries. The focus of organic production is usually based on environmental sustainability and human wellbeing (3).
The ‘EU organic logo’ can be used when 95% of the ingredients in a product meet the EU Organic Regulation standards (4).
This EU Organic Regulation, focuses on (4):
- Sustainability farming
- Using natural cycles related to plant life, seasons and the local environment
- Using natural fertilisers and pesticide methods, rather than synthetic chemicals
- Animal welfare
- Producing high-quality products
- Consumer protection
- Reduced reliance on genetically modified organisms (GMOs)
GMOs are plants or animals which have a desirable characteristic added to it, by changing or adding a specific gene (5). For example, a gene can be added to a plant to make it resistant to certain diseases, or resistant to pests so that chemical pesticides aren’t needed (5).
Organic products can still use GMOs and synthetic materials when there are no other suitable options available (4) For example, synthetically-made medicine can be used for a sick or injured animal which needs urgent treatment (6). However, this can’t be used to prevent disease, and alternative medicine approaches are preferred in organic farming – including herbal medicine and homeopathy (despite a lack of evidence for this) (6, 7).
In the UK organic food may also be certified with the Soil Association organic logo. This means that the product meets the EU organic standards, as well as a higher set of higher standards which include further guidelines to protect animals, people and the environment. For more information about this, you can check out the Soil Association’s website.
So organic production has a stronger focus on sustainability and conservation. However, there can still be quite an overlap between organic and conventional farming – depending on the location in question, and which methods which are used.
Organic Food and the Environment:
The impact of our diet on the environment is a complex issue, and there is often no single answer which suits all situations.
In general, organic food production strives to have a low environmental impact by: conserving soil quality, protecting the diversity of living creatures and reduced reliance on synthetic chemicals (3).
However, organic isn’t necessarily better for the environment overall. For example, it has been found that organic farming tends to cause more eutrophication and emit similar greenhouse gas emissions as compared with conventional farming (8). Organic farming may also use 25% to 110% more land as compared with conventional farming (8).
Furthermore, choosing organic food instead of conventionally produced food is thought to have a much smaller impact than the type of food which is consumed. For example, eating a more plant-based diet is associated with substantial environmental benefits, regardless of whether the plants were organically grown or not (8, 9, 10).
Organic Food and Health:
There is some mixed evidence about whether consuming organic or conventional food is better for our health, but overall there seems to be little difference. For example, a good quality study from 2012 found no differences in terms of allergy or infection risk between people who consumed organic or non-organic food (11). Some studies have found a link between consuming organic food with having a healthier weight (12). But this is only a weak link, because people who buy organic food also tend to make a number of healthy lifestyle choices (13).
Some people are concerned about the pesticide content of conventionally-produced food. Conventional produce tends to have higher levels of pesticides as compared to organic products (14). However, organic products can still go above the recommended safety limits (14).
The thing is, we also don’t know whether consuming pesticides is harmful. Some research has found that high exposure to pesticides in early life has been may harm cognitive development in children; but findings have been mixed about this (9). And a recent study found that frequent exposure to pesticides for adults caused an insignificant amount of harm – in fact it had the same health impact as having just one glass of wine every seven years (15)!
Organic vegetables tend to contain lower nitrate levels. Nitrate is a naturally occurring compound which is thought to be good for maintaining healthy blood pressure and boosting athletic performance (due to improved blood flow). However, there is a limit on the amounts of nitrate we should consume (3.7 mg per kg body weight per day) – because versions of this have been linked with an increased cancer risk. But the benefits of consuming vegetables, whether organic or not, is seen to far out-weigh the possible risks related to nitrate intake (13, 16).
Organic products may have a slightly higher risk of contamination with pesticides or antibiotic-resistant bacteria (11, 17). However, the research is mixed about this, other production factors are more likely to cause contamination and there isn’t good evidence that this contamination is harmful (11, 17).
Most studies have found no significant difference between organic and non-organic food In terms of nutritional content. However a few studies did find that organic products may be slightly higher in phosphorus, but lower in protein (11, 18). Similarly, organic milk may contain slightly higher levels of omega-3, vitamin E and iron; but less selenium and iodine than non-organic milk (19). Organic meat may also contain slightly higher levels of omega-3 (20). However, these small nutritional differences are thought to have an insignificant effect on our overall health. The nutritional content of food can also be impacted by a host of factors, regardless of whether the product is certified as organic. For example, the nutritional content of milk can be affected by: the location of the cattle, the time of year and whether they were grass-fed or not.
Opinions are divided about whether the avoidance of GMOs is positive or negative. In terms of health there is no good evidence that they cause harm to humans (8). In fact there are a number of very beneficial uses of GMOs, such as fortifying rice in developing countries with vitamin A in order to prevent deficiency – which can save lives. You can find out more about this ‘golden rice’ here.
Looking at human health from a wider lens, the fact that organic products discourage the use of antibiotics is very positive, considering the worldwide problem of antibiotic resistance. Although this has less of an impact in the EU, as antibiotics in the production of animal products occurs much less often than in countries like the US (21). For more information on antibiotic resistance, see Hazel’s article ‘Keep Antibiotics Working’.
Overall, there is no strong evidence to say that choosing either organic or conventional food is better for our health on an individual level. The type of food we eat will have a much bigger impact than whether it is organic or not. So it is better to focus on having a balanced diet which includes lots of plant-based foods, as shown in The Eatwell Guide.
The ‘Dirty Dozen’ and ‘Clean 15’
The so-called ‘dirty dozen’ is an annual list of conventionally-grown fruit and vegetables which are thought to contain the highest pesticide levels in the US.
The ’dirty dozen’ for 2018 were (22):
- Strawberries 🍓
- Spinach 🌱
- Nectarines 🔴
- Apples 🍎
- Grapes 🍇
- Peaches 🍑
- Cherries 🍒
- Pears 🍐
- Tomatoes 🍅
- Celery 🌿
- Potatoes 🥔
- Sweet Bell Peppers 🌶
The ‘clean 15’ is a similar list of the 15 conventionally grown fruits and vegetables which are thought to have the lowest level of pesticide residue.
The ‘clean 15’ for 2018 were (23):
- Avocado 🥑
- Sweetcorn 🌽
- Pineapple 🍍
- Cabbage 🥬
- Frozen sweet peas
- Mango 🥭
- Eggplant (aubergine) 🍆
- Honeydew melon 🍈
- Kiwi 🥝
- Canteloupe 🍈
Both lists are created by the Environmental Working Group – this is a non-profit group which promote organic farming. These lists are created by running further tests on pesticide data from the US department of Agriculture (USDA), so foods which contain more types of pesticides are higher in the ‘dirty dozen’ list. However, this distorts the original data from the USDA, because the pesticide level for vast majority of fruit and vegetables is well below safety limits (so even if a strawberry contains more pesticides than a mango – both are within safe limits). For example, in 2017 “more than 99 percent of the samples tested had pesticide residues well below benchmark levels established by the Environmental Protection Agency (EPA)” – but regardless of this the ‘dirty dozen’ and ‘clean 15’ were published as usual (24). As discussed above, we also don’t know whether consuming pesticides poses a significant health risk for humans.
So these lists don’t apply outside of the US, and even for food which is produced within the US there is no need to choose or avoid specific foods based on this. Rather than following these lists, it is better to eat plenty of fruit and vegetables, and washing these before use.
Organic food must comply with specific standards related to sustainability and conservation. But because organic farming tends to use more land and resources, it isn’t always better for the environment overall. The environmental impact of a food is more likely to be affected by the overall methods used for production, storage and transport. The type of food being produced also has a bigger impact than whether is it organic – for example producing plant-based foods is usually much better for the environment.
There is also no strong evidence that replacing conventional products with organic products improves our health. And there is no need to follow the ‘dirty dozen’ and ‘clean 15’ lists. What we eat and the overall balance in our diet is much more important.
If you prefer organic products and if you don’t mind the higher cost, then there is no harm in choosing these. But for many people it is more realistic, cost-effective and beneficial to focus on adding more plants to their diet, rather than switching to organic products.
- The Soil Association (2018) “The Organic Market Report” [Accessed November 2018 via: https://www.soilassociation.org/certification/market-research-and-data/the-organic-market-report/]
- United States Department of Agriculture “SDA-ERS, Organic prices 2016” [Accessed November 2018 via: https://www.ers.usda.gov/data-products/organic-prices/]
- International Federation of Organic Agriculture Movement “Definition of organic agriculture” [Accessed November 2018 via: http://www.ifoam.org/en/organic-landmarks/definition-organic-agriculture]
- European Commission “EU Law on Organic Production: An Overview” [Accessed November 2018 via: https://ec.europa.eu/agriculture/organic/eu-policy/eu-legislation/brief-overview_en]
- Sense About Science “Making Sense of GM” [Accessed November 2018 via: https://senseaboutscience.org/activities/making-sense-of-gm/]
- Commission Regulation (EC) No 889/2008 of 5 September 2008 laying down detailed rules for the implementation of Council Regulation (EC) No 834/2007 on organic production and labelling of organic products with regard to organic production, labelling and control [accessed January 2019 via: https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=uriserv:OJ.L_.2008.250.01.0001.01.ENG]
- Doehring & Sundrum (2016) “Efficacy of homeopathy in livestock according to peer-reviewed publications from 1981 to 2014” [Accessed January 2019 via: https://veterinaryrecord.bmj.com/content/179/24/628]
- Clark & Tilman (2017) “Comparative analysis of environmental impacts of agricultural production systems, agricultural input efficiency, and food choice” [Accessed November 2018 via: http://iopscience.iop.org/article/10.1088/1748-9326/aa6cd5]
- Food and Agriculture Organization of the United Nations (2013) “Tackling Climate Change Through Livestock” [Accessed November 2018: http://www.fao.org/3/a-i3437e.pdf]
- Poore & Nemecek (2018). Reducing food’s environmental impacts through producers and consumers. Science. 2018; 360(6392): 987-992 [Accessed November 2018 via: https://www.ncbi.nlm.nih.gov/pubmed/29853680]
- Smith-Spangler et al. (2012) “Are organic foods safer or healthier than conventional alternatives? A systematic review” Ann Intern Med. 2012;157:348-366 [Accessed November 2018 via: https://www.ncbi.nlm.nih.gov/pubmed/22944875]
- Mie et al. (2017) “Human health implications of organic food and organic agriculture: a comprehensive review” [Accessed November 2018 via: https://www.ncbi.nlm.nih.gov/pubmed/29073935]
- Kesse-Guyot E et al. (2013) “Profiles of organic food consumers in a large sample of French adults: results from the Nutrinet-Sante cohort study” PLoS One. 2013;8(10): e76998).
- European Food Safety Authority (2011) “The 2009 European Union report on pesticide residues in food” [Accessed November 2018 via: http://www.efsa.europa.eu/en/efsajournal/pub/2430.htm]
- Larsson et al. (2018) “Refined assessment and perspectives on the cumulative risk resulting from the dietary exposure to pesticide residues in the Danish population” [Accessed November 2018 via: https://www.ncbi.nlm.nih.gov/pubmed/29155356]
- EFSA (2018) “Nitrate in vegetables Scientific Opinion of the Panel on Contaminants in the Food chain” [Accessed January 2019 via: http://www.efsa.europa.eu/sites/default/files/scientific_output/files/main_documents/689.pdf]
- Teixeira et al. (2016) “Organic versus conventional food: A comparison regarding food safety” [Accessed November 2018 via: https://www.tandfonline.com/doi/abs/10.1080/87559129.2016.1196490?scroll=top&needAccess=true&journalCode=lfri20]
- Dangour et al. (2009) “Nutritional quality of organic foods: a systematic review”. Am J Clin Nutr [Accessed November 2018 via: https://www.ncbi.nlm.nih.gov/pubmed/19640946].
- Średnicka-Tober et al. (2016) “Higher PUFA and n-3 PUFA, conjugated linoleic acid α-tocopherol and iron, but lower iodine and selenium concentrations in organic milk: a systematic literature review and meta- and redundancy analyses” Br J Nutr. 115(6):1043-1060.
- Średnicka-Tober et al. (2016) “Composition differences between organic and conventional meat: a systematic literature review and meta-analysis” Br J Nutr; 115(6):994-1011.
- European Commission (2005) “Ban on antibiotics as growth promoters in animal feed enters into effect” [accessed November 2018 via: http://europa.eu/rapid/press-release_IP-05-1687_en.htm]
- The Environmental Protection Group “Shoppers Guide to Pesticides in Produce: Dirty Dozen” [accessed January 2019 via: https://www.ewg.org/foodnews/dirty-dozen.php]
- The Environmental Protection Group “Shoppers Guide to Pesticides in Produce: Dirty Dozen” [accessed January 2019 via: https://www.ewg.org/foodnews/clean-fifteen.php]
- USDA Website “USDA Releases 2017 Annual Pesticide Data Program Summary, U.S. Food Supply is Among the Safest in the World” [Accessed January 2019 via: https://www.ams.usda.gov/press-release/usda-releases-2017-annual-pesticide-data-program-summary-us-food-supply-among-safest]