In this article I summarize the most striking facts that led me to the following conclusions: 1) that, from an average consumer point of view, buying organic food is not clearly better nor worse than non-organic food in terms of environmental or health impact and 2) that, from an effective altruist point of view, if you have the choice between buying a more expensive organic product or an equivalent less expensive non-organic product, it is better to buy the non-organic product, save money on food expenditures and donate this saved money to the most effective charities.
- Organic has more land use and eutrophication than non-organic. According to a recent meta-analysis and systematic review of the scientific literature (Clark M. & Tilman D. 2017, Comparative analysis of environmental impacts of agricultural production systems, agricultural input efficiency, and food choice. Environmental Research Letters12:6), comparing organic products with non-organic products per unit of product, the organic products require on average more land (hence more loss of natural habitat if we increase organic food production) and cause more eutrophication (oxygen depletion and disturbance of water ecosystems due to excessive levels of nitrogen and phosphorus runoff into the rivers). Organic requires more land due to lower yields (due to avoidance of synthetic pesticides) and application of green manure and animal manure (requiring extra land). Organic has higher eutrophication because using animal manure doesn’t allow to choose the right doses of nutrients (nitrogen, phosphorus and potassium) to help supplement the specific shortcomings in the soil and to meet the needs of the crops more accurately. Synthetic fertilizers can be composed in the right amounts and applied at the right moments according to the needs of the crops. Weed control in organic farming also can require more tilling of the soil, which increases nutrient runoff and eutrophication. This is in line with three other meta-analyses, so the evidence is pretty strong (Mondelaers, K., Aertsens, J., Van Huylenbroeck, G. 2009, A meta-analysis of the differences in environmental impacts between organic and conventional farming. British Food Journal 111 (10), 1098-1119. Tuomisto H. e.a. 2012, Does organic farming reduce environmental impacts? A Meta-Analysis of European research. Journal of Environmental Management 112, 309-320. Seufert V. e.a. 2012, Comparing the yields of organic and conventional agriculture. Nature 485, 229–232.)
- Organic and non-organic have equal impacts on climate change and acidification. In terms of emissions of greenhouse gases and acidifying substances, the meta-analyses indicate no difference between organic and non-organic.
- We do not yet know whether organic is better or worse for global biodiversity. Organic farms have more biodiversity on their fields, but are a stronger threat to biodiversity of natural habitats. Having a higher land use and more eutrophication threatens biodiversity of natural habitats, because turning natural habitat into farmland or polluting natural habitat with excess nutrients decreases biodiversity. The overall effect of organic farming on biodiversity remains unclear (Hole, D.G e.a. 2005. Does organic farming benefit biodiversity? Biological Conservation. 122 (1): 113–130). One study attempted to estimate the overall impact of farming systems on biodiversity and concluded that there is no relevant difference between organic and non-organic farming. (Gabriel, D., Sait, S.M., Kunin, W.E. & Benton, T.G. 2013, Food production vs. biodiversity: comparing organic and conventional agriculture. Journal of Applied Ecology, 50, 355–364.) Another review study says the evidence largely supports the idea that having a higher yield (as in non-organic farming), enabling larger areas kept as natural habitats, is better for biodiversity than having lower yields (as in organic farming), enabling more biodiversity on the field but less natural habitat (Balmford, A. e.a. 2015, Land for Food and Land for Nature? Daedalus 144(4), 57-75). But important questions remain.
- Organic farming allows the application of toxic pesticides, such as copper sulphate (very persistent and more than 10 times more toxic than alternative synthetic fungicides), and pesticides (e.g. pyrethrine, azadirachtin, rotenone, eucalyptus oil, neem oil) that are harmful to non-target invertebrates such as bees (Xavier V, e.a. 2015, Acute Toxicity and Sublethal Effects of Botanical Insecticides to Honey Bees, Journal of Insect Science, 15:1). According to one study for soybeans, organic pesticides were less effective in controlling aphids, were as toxic or more toxic for non-target invertebrates and had higher Environmental Impact Quotients than synthetic pesticides (Bahlai, C., Xue, Y., McCreary, C., Schaafsma, A., & Hallett, R. 2010, Choosing Organic Pesticides over Synthetic Pesticides May Not Effectively Mitigate Environmental Risk in Soybeans, PLoS ONE, 5:6).
- Organic farming can be worse for biodiversity than GMO farming. Organic farming does not allow the use of Bt-crops, which are GMOs that produce a Bt-toxin that acts as an insecticide. However, organic farming does allow the spraying of that same Bt-insecticide. The Bt-insecticide produced by plants and used in the Bt-GMOs is as natural and safe (for humans) as the Bt-insecticide produced by bacteria and sprayed by organic farmers. However, according to a meta-analysis, the Bt-GMOs are better for biodiversity, in particular for nontarget (harmless) invertebrates (Marvier M, McCreedy C, Regetz J, Kareiva P. 2007, A meta-analysis of effects of Bt cotton and maize on nontarget invertebrates. Science 316(5830):1475–7). This study compares three kinds of fields: one where no GMO crops are used and where Bt is sprayed (which can also be an organic field), one where Bt-GMO crops are used and no Bt is sprayed, and one where no GMO crops are used and no Bt is sprayed. The latter field has the highest biodiversity of nontarget invertebrates, but it also has lower yields and hence requires more land and hence more habitat loss, so it is not necessarily the most biodiversity friendly field. The first field (which can be an organic field) has the lowest biodiversity of nontarget invertebrates, because spraying insecticides causes more collateral damage. When the insecticide is produced in the plant, only the harmful target invertebrates are affected.
- The organic rules involving unintended contamination are unfair. Organic farming does not allow the use of GMO crops. When a neighbouring farmer uses GMOs, organic farmers fear losing their organic label due to a risk of cross-pollination or unintended GMO contamination of their own fields that should remain strictly GMO free. As GMOs are not more harmful to the environment or human health than new organic plant breeds whose genes can also unintentionally contaminate neighbouring areas, there is no reason why organic farming should be so strict about excluding GMOs. As a result of these strict rules, organic farmers complain against neighbouring non-organic farmers who use GMOs that pose a threat of contamination, making coexistence of GMO and organic farming difficult. But the real unfairness works in the reverse direction: from organic farms to neighbouring non-organic farms. Organic farmers have more difficulties controlling pests, so pests can develop and migrate to neighbouring farms. This is also an unintentional, uncontrolled spreading of something harmful, and organic farmers have a causal responsibility in this, because they refused to apply more effective pest control methods. So non-organic farmers could complain against organic farming. Reversely, effective pest management and the use of virus- and insect resistent GMOs on neighboring farms can create a protective buffer around organic farms, making organic pest management (avoiding synthetic pesticides) easier. Also note that organic farmers are allowed to use crops bred from artificial mutagenesis, which is at least as risky as genetic modification in terms of introductions of new genes and gene combinations. So if GMOs pose a risk of dissemination of new genes to the environment, then organic farming also poses such a risk from artifically mutagenized crops.
- Biological pest control can result in the uncontrolled spreading of invasive species that is harmful to local biodiversity. Organic farmers warn against the imagined risks of GMOs, in particular the threat of cross-pollination and uncontrolled spreading of the GMO genes into the environment, resulting in biodiversity loss. But such effects of biodiversity loss due to GMO crops have never been observed even if GMOs are planted for decades on thousands of hectares. And there is no clear reason why GMOs would pose a more dangerous threat than the new crop breeds used by organic farmers. And most of all: organic farming did already have some examples of an uncontrolled spreading of something exotic, threatening local biodiversity. As an alternative to pesticides, organic farming often uses biological pest control, introducing insects (ladybirds, weevils, wasps) to control pests (weeds, aphids). Sometimes those introduced insects are invasive and threaten local biodiversity. (Vilcinskas A. e.a. 2013, Invasive Harlequin Ladybird Carries Biological Weapons Against Native Competitors, Science340 (6134): 862-863. Louda S. e.a. 1997, Ecological Effects of an Insect Introduced for the Biological Control of Weeds, Science 277:1088-90. Strong D.R. 1997, Fear No Weevil, Science 277:1058-59.)
- Organic products are too expensive to cover environmental costs. The additional cost (higher price) of organic food is an order of magnitude higher than the externality cost of environmental pollution of non-organic farming. In the Netherlands, a study claims that organic farming saves about 10 million euro per year in negative external effects (Meeusen, M.J.G., S. Reinhard & E.J. Bos 2008, Waardering van de duurzaamheidsprestaties van de Nederlandse biologische landbouw, LEI Wageningen University). These negative external effects or environmental costs include e.g. the cost to purify the water from the pesticides used in non-organic farming. This value is an overestimation, because the study did not properly take into account the higher land use and eutrophication levels per unit product for organic production. The Dutch people spend about 1130 million euro per year on organic food. If organic food is about 30% more expensive, that implies an extra cost (surplus spending) of 280 million euro for organic food. This is 28 times higher than the savings (lower externality costs) resulting from organic farming. In other words: in the Netherlands, due to organic farming society spend 10 million euro less in environmental costs, but consumers spend about 280 million euro extra due to the higher prices of organic products. Taxing food to internalize the negative external environmental costs in the price of the product can be done in a more effective way.
- Organic farming allows the use of finite, depletable resources such as fossil fuels and mineral fertilizers. The production of synthetic nitrogen fertilizer uses fossil fuels, the production of synthetic phosphate fertilizer uses rock minerals. Both resources are exhaustible. However, synthetic nitrogen fertilizer can also be produced with renewable energy instead of fossil fuels. Organic farming also uses fossil fuels (e.g. for tilling machines, for burning down weeds) and allows the use of rock phosphate to produce organic phosphate fertilizers. The animal manure used in organic farming is often produced by animals who eat a lot of crops fertilized with synthetic fertilizers produced from depletable resources. In this sense, we cannot say that organic is more sustainable.
- Many studies about the benefits of organic farming or the harms of GMOs were done by researchers and institutions who had conflict of interests with the organic agriculture sector. Some names include: Charles Benbrook (had undisclosed conflicts of interest: worked at the Organic Center and research was funded by Whole Foods, Organic Valley, United Natural Foods, Organic Trade Association and others), Gilles-Eric Séralini (consultant of Sevene Pharma that sells homeopathic antidotes against pesticides), Judy Carman (anti-GMO research was funded by Verity Farms and published in a journal sponsored by the Organic Federation of Australia) and the Rodale Institute.
Human health impact
- Critical review studies of the scientific literature are not able to indicate whether organic food is better or worse for human health. For some food products and some nutrients and some toxics, organic is better, but for others it is the same or worse than non-organic. The overall effect is unclear. (Dangour, A., Lock, K., Hayter, A., Aikenhead, A., Allen, E., & Uauy, R. 2010, Nutrition-related health effects of organic foods: a systematic review American Journal of Clinical Nutrition, 92(1), 203-210. Smith-Spangler C. e.a. 2012, Are organic foods safer or healthier than conventional alternatives?: a systematic review. Ann Intern Med. 157(5):348-66. Magkos F. e.a. 2006, Organic Food: Buying More Safety or Just Peace of Mind? A Critical Review of the Literature. Critical Reviews in Food Science and Nutrition, 46:23–56.) For example organic animal products may contain higher levels of unhealthy trans fatty acids and dioxins. Organic milk can contain higher levels of healthy omega-3 poly unsaturated fatty acids and iron, but lower levels of essential minerals such as iodine and selenium. (Średnicka-Tober D. e.a. 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):1043-60.) If there are differences in levels of nutrients or toxins, the differences between organic and non-organic are small.
- Some restrictive organic food regulations make organic foods less healthy. For example enrichment with vitamins is not allowed in e.g. organic soy milk. Non-organic soy milk enriched with calcium and vitamins B12 and D can be healthier than non-enriched organic soy milk as well as cow milk.
- Organic crops can have higher levels of mycotoxines. Organic farmers use no synthetic fungicides on cereal crops. Combined with a higher sugar content in organic cereal crops, this makes these organic crops more vulnerable to fungicides that produce toxic mycotoxins. On the other hand, organic farming does not allow the use of GMOs such as Bt-corn. As Bt-corn is less vulnerable to damage from insects that carry fungi with them, Bt-corn is less infected with the fungi that produce mycotoxins. (Wu F. (2006) Mycotoxin reduction in Bt corn: potential economic, health, and regulatory impacts. Transgenic Res. 15(3):277-89.)
- Organic food products can have higher health risks from dangerous bacteria. Due to the application of animal manure (that is not treated with non-organic radiation or antibiotic means to kill the bacteria), organic crops can have a higher risk of contamination with dangerous E.coli bacteria. (Mukherjee A, Speh D, Dyck E, & Diez-Gonzalez F 2004, Preharvest evaluation of coliforms, Escherichia coli, Salmonella, and Escherichia coli O157:H7 in organic and conventional produce grown by Minnesota farmers. Journal of food protection, 67(5), 894-900.)
- The health impact of pesticide residues in food, and the difference between organic and non-organic, is negligible. Almost all measured levels of pesticide residues on non-organic foods are below very strict maximum allowable levels, such that expected health impacts are negligible. 99,99% of pesticides in fruits and vegetables are produced by the plants themselves to protect themselves against insects and fungi. These pesticides cannot be avoided. Only 0,01% are pesticide residues from the application of pesticides by the farmer. Also organic foods can contain pesticide residues from applied organic pesticides. On average, the natural pesticides produced by the plants are as toxic (carcinogenic) as the pesticides applied by the farmers. (Ames BN, Profet M, Gold LS. 2009, Dietary pesticides (99.99% all natural). Proc Natl Acad Sci87:777–81. Ames BN, Gold LS. 1997, Environmental pollution, pesticides, and the prevention of cancer: misconceptions. FASEB J. 11(13):1041-52.) Organic products can contain higher levels of plant-produced pesticides because organic farmers use crop breeds that are more resistant to insects and fungi. These more resilient organic breeds produce more pesticides to defend themselves. But even if both organic and non-organic fruits and vegetables contain toxic pesticides (natural and residues), these products also contain very high levels of healthy chemicals that protect against cancer and toxic effects; so both organic and non-organic fruits and vegetables are very healthy overall. As a comparison, one study estimates that the reduction of cancer risk from consuming healthy chemicals in fruits and vegetables is 2000 times higher than the increased cancer risk of pesticide residues. For every case of cancer from pesticide residues on fruits and vegetables, 2000 cases of cancer can be avoided by eating those fruits and vegetables. (Reiss R. e.a. 2012, Estimation of cancer risks and benefits associated with a potential increased consumption of fruits and vegetables. Food and Chemical Toxicology 50(12):4421-4427). As an intriguing fact, note that some studies indicate that organic food has higher levels of healthy antioxidants or polyphenols. The reason is that those chemicals are produced by the plants to act as pesticides (deterrence of herbivores and prevention of microbial infections). Even some pesticides can be healthy.
- Buying more expensive organic food to reduce health risks is irrational. The abovementioned study about cancer risks of fruits and vegetables says that the cancer risk from pesticide residues on fruit and vegetables is at most 1 in 15 million per year. To simplify the calculation, let us suppose that the overall mortality from the consumption of non-organic food is 15 times higher, which means 1 death per year per 1 million people who do not consume organic products (not all of the cancers result in death, but there can also be non-cancer risks and there is also consumption of other products than fruit and vegetables). This mortality risk corresponds with 1 micromort per year: a 1 in a million probability to die. Suppose you want to eliminate that risk by eating 100% organic products. Organic food is on average 30% to 50% more expensive, so buying 100% organic results in an additional cost of about 600 euro per year (33% extra costs on a total yearly food consumption budget of 1800 euro per person). However, looking at safety measures (e.g. in traffic, safety features in cars) we see that the maximum willingness to pay to eliminate a mortality risk of one micromort is about 50 euro. People are not willing to pay more than 50 euro to eliminate a micromort risk. This is an order of magnitude (factor 10) lower than the extra cost of organic food. As a comparison, driving 20 km by bike also has a mortality of one micromort, because driving a bike can result in a deadly accident. How much money are you willing to pay in order to eliminate that mortality risk for every 20 km that you drive a bike? Are you willing to pay 600 euro? If that is too much, but if you are willing to pay extra for organic food in order to reduce your mortality risk, your choice for organic food is irrational. We can also look at the value of a statistical life: how much we as a society are willing to pay to save 1 life. This value is about 10 million euro. If 1 million people buy 100% organic instead of 100% non-organic for one year, they will each avoid 1 micromort and hence in total they avoid one death. Together, those people pay an additional cost of 1 million times 600 euro. This is 60 times higher than the value of a statistical life, which means again that organic food is too expensive to justify buying it in order to reduce health risks.
- Instead of focussing on organic food, we should rather focus on vegan (animal free, plant based) food. Veganism does have multiple benefits for both the environment and human health. It has lower land use, water use, pesticide use, energy use, greenhouse gas emissions, eutrophication, acidification and other kinds of pollution and resource use. See here and the abovementioned the meta-analysis (Clark M. & Tilman D. 2017, Comparative analysis of environmental impacts of agricultural production systems, agricultural input efficiency, and food choice. Environmental Research Letters12:6). Compared to organic food, review studies show that there is much more scientific evidence for the health benefits of plant-based diets (Springmann M. e.a. 2016, Analysis and valuation of the health and climate change cobenefits of dietary change. PNAS. Orlich MJ. e.a. 2013, Vegetarian Dietary Patterns and Mortality in Adventist Health Study 2. JAMA Intern Med.173(13):1230-1238. Dinu M. e.a. 2016, Vegetarian, vegan diets and multiple health outcomes: a systematic review with meta-analysis of observational studies. Crit Rev Food Sci Nutr. Huang T., e.a. 2012, Cardiovascular Disease Mortality and Cancer Incidence in Vegetarians: A Meta-Analysis and Systematic Review. Ann Nutr Metab; 60:233–240).
- Spending money on the most effective charities instead of organic food does more good. An average person in Belgium buys 1% organic and spends about 25 euro per year on organic food, which means an extra expenditure of 6 euro due to the higher price of organic. Over a lifetime, this is an extra expenditure of 500 euro. There are effective human health charities such as the Against Malaria foundation that can save 5 to 10 healthy life years (quality adjusted life years or QALYs) with a donation of 500 euro. It is very unlikely that a person in Belgium will lose 5 or 10 healthy life years when he or she consumes 0% instead of merely 1% organic food. In other words: buying cheaper non-organic food and donating the saved money to the most cost-effective health charities (recommended by the charity evaluator GiveWell), will do much more good in the world in terms of global health. When you are concerned about the environment, you can donate the money to the most effective environmental charities, in particular organisations that promote plant-based diets (e.g. recommended by Animal Charity Evaluators).