REFERENCES: EFFECTS OF INDUSTRIAL ANIMAL AGRICULTURE ON ENV’T/ HUMAN HEALTH

🍎 The below is a body of evidence around the Impacts of Industrial Animal Agriculture' on environment and climate change & the benefits of more Plant-forward eating patterns on human and planetary health

 

Be sure to look at other sections in this area on sustainable diets as there is likely to be crossover.  Below are also papers focused on the impact of industrial animal agriculture on the environment and climate and the benefits of plant based diets for health and planet. Please note that there is evidence that animal protein may be necessary and essential  in certain regions of the world and that animal agriculture done in a way that is ecologically friendly and humane can be important culturally, economically, and health-wise.  If you are looking for a place to start, check out the papers marked with *** which indicates papers that are recent and, in my opinion, very well laid out.

Please note: These articles have been update through January, 2024

  • Barré T, Perignon M, Gazan R, et al. Integrating nutrient bioavailability and co-production links when identifying sustainable diets: How low should we reduce meat consumption? PLOS ONE. 2018;13(2).
    • Reducing the consumption of meat and other animal-based products is widely advocated to improve the sustainability of diets in high-income countries. However, such reduction may impair nutritional adequacy, since the bioavailability of key nutrients is higher when they come from animal- vs plant-based foods.
  • Biesbroek S, Kok FJ, Tufford AR, et al. Toward healthy and sustainable diets for the 21st century: Importance of sociocultural and economic considerationsProc Natl Acad Sci U S A. 2023;120(26):e2219272120. doi:10.1073/pnas.2219272120
    • Substantive evidence shows that a high consumption of red and processed meat contributes to higher risk of NCDs and premature death, while they can be substituted with moderate amounts of poultry, seafood, dairy, nuts and seeds, and legumes (4). Moreover, there is strong evidence and biological plausibility to support the beneficial roles of minimally processed plant-based foods including fruits, vegetables, nuts, seeds, whole grains, and legumes (5). Contrarily, ultraprocessed foods and drinks (UPF) which are highly palatable provide high amounts of energy, saturated fat, salt, sugar, and diverse additives while they are easily consumed in large amounts and are associated with obesity and NCDs (6).
    • Overall, a hierarchy between food categories and greenhouse gas emissions (GHGE) is observed, with plant-based foods having the lowest and animal-based foods the highest impact per kg of food (7). Incorporating the local context by extending GHGE as a global indicator with locally relevant parameters such as land and water use, eutrophication of waterways, presence of heavy metals or pesticides, and biodiversity losses would add valuable information to better assess cobenefits and trade-offs at local and national levels and develop national food-based dietary guidelines (FBDGs) for sustainable diets.
    • Context-specific dietary changes therefore depend on the national burden of disease (obesity or undernutrition), environmental challenges, and cultural traditions. For example, increasing meat and dairy consumption would help improve current inadequacies in many low- and middle-income countries (LMICs) while most HICs should limit their consumption because of high NCD risks and environmental footprints.
      • Note from Mary Purdy: Agreed! Context is everything.
  • Burkholder, J., Libra, B., Weyer, P., Heathcote, S., & al, e. Impacts of waste from concentrated animal feeding operations on water quality. Environmental Health Perspectives, 115(2), 308-12. (2007)
    • Based on available data, generally accepted livestock waste management practices do not adequately or effectively protect water resources from contamination with excessive nutrients, microbial pathogens, and pharmaceuticals present in the waste. Impacts on surface water sources and wildlife have been documented in many agricultural areas in the United States. 
    • The recent growth of concentrated animal feeding operations (CAFOs) presents a greater risk to water quality because of both the increased volume of waste and to contaminants that may be present (e.g., antibiotics and other veterinary drugs) that may have both environmental and public health importance.
  • Chai BC, van der Voort JR, Grofelnik K, Eliasdottir HG, Klöss I, Perez-Cueto FJA. Which diet has the least environmental impact on our planet? A Systematic review of vegan, vegetarian and omnivorous diets. Sustainability. 2019; 11(15):4110.

    • Life Cycle Impact Assessment technique (LCAs) [8]. LCAs can estimate the environmental impacts of production, transport, processing, storage, waste disposal and other life stages of food production 
    • Using natural resources (land, water and fossil energy) to raise livestock and produce crops increases environmental degradation day by day.
    • Results from our review suggest that the vegan diet is the optimal diet for the environment because, out of all the compared diets, its production results in the lowest level of GHG emissions.
    • Additionally, the reviewed studies indicate the possibility of achieving the same environmental impact as that of the vegan diet, without excluding the meat and dairy food groups, but rather, by reducing them substantially.
  • Center for a Livable Future Report. Johns Hopkins University.  The Importance of Reducing Animal Product Consumption and Wasted Food in Mitigating Catastrophic Climate Change. COP 21. 2015

    • If global trends in meat and dairy intake continue, global mean temperature rise will more than likely exceed 2° C, even with dramatic emissions reductions across non‐agricultural sectors.
    • Immediate and substantial reductions in wasted food and meat and dairy intake, particularly ruminant meat (e.g., beef and lamb), are imperative to mitigating catastrophic climate change.
  • Clark MA, et al. Global food system emissions could preclude achieving the 1.5° and 2°C climate change targets. Science 370,705-708(2020).DOI:10.1126/science.aba7357
    • GHG emissions from the global food system largely occur from food production and from land being cleared for food production. Emissions from food production are calculated by pairing life cycle assessment estimates of the GHG emissions per unit of each type of food (8) with their forecasted total global demand, and these estimates include emissions from activities such as production of agricultural inputs, fertilizer application, and animal husbandry.
    • Our estimates of emissions from supply chains do not include emissions from transportation, processing, packaging, retail, and preparation, which in total account for a minor fraction (~17%) of total food system emissions 
  • Clark et al.  SUMMARY PAPER 2: The role of healthy diets in creating environmentally sustainable food systems World Health Organization/FAO ”SUSTAINABLE HEALTHY DIETS GUIDING PRINCIPLES” (2019)
    • “Global adoption of a low-meat diet that meets nutritional recommendations for fruits, vegetables, and caloric requirements is estimated to reduce diet-related GHGs by nearly 50 percent, and premature mortality by nearly 20 percent. “
    • “In addition to dietary changes, other changes to the food system could further reduce its environmental impact, including reductions in food loss and waste; technology implementation and changes in management to improve crop yields and reduce fertilizer and pesticide runoff; and changes in food formulation, processing, and preparation.”
    • “The benefits of adopting environmentally sustainable and healthy diets will vary by country”
  • Craig WJ, Mangels AR, Fresán U, Marsh K, Miles FL, Saunders AV, Haddad EH, Heskey CE, Johnston P, Larson-Meyer E, Orlich M. The Safe and Effective Use of Plant-Based Diets with Guidelines for Health Professionals. Nutrients. 2021 Nov 19;13(11):4144.
    • An increasing body of data provides evidence that environmental degradation, through the emissions of greenhouse gas (GHG) and other pollutants, and the use of earth’s resources, such as water and land, in the production of plant-based foods are significantly lower than that from animal-based foods
    • The production of plant-based products is more efficient regardless of whether the comparison is made by weight of product, per serving, per calories, or even protein content
    • Producing the same amount of protein from tofu (soybeans) in comparison to beef protein requires 74 times less land and eight times less water, while the GHG emissions are 25 times lower and the eutrophication (a process driven by the enrichment of water by nutrients, especially compounds of nitrogen and/or phosphorus, leading to an increased growth, primary production and biomass of algae; changes in the balance of organisms; and water quality degradation
  • Eisen MB, Brown PO. Rapid global phaseout of animal agriculture has the potential to stabilize greenhouse gas levels for 30 years and offset 68 percent of CO2 emissions.

    • Animal agriculture contributes significantly to global warming through ongoing emissions of the potent greenhouse gases methane and nitrous oxide, and displacement of biomass carbon on the land used to support livestock.
    • Even in the absence of any other emission reductions, persistent drops in atmospheric methane and nitrous oxide levels, and slower carbon dioxide accumulation, following a phase out of livestock production would, through the end of the century, have the same cumulative effect on the warming potential of the atmosphere as a 25 gigaton per year reduction in anthropogenic CO2 emissions, providing half of the net emission reductions necessary to limit warming to 2°C.
  • FAO. 2020. Livestock and environment statistics: manure and greenhouse gas emissions. Global, regional and country trends, 1990–2018. FAOSTAT Analytical Brief Series No. 14. Rome.
    • Two-thirds of agricultural emissions come from grazing livestock, with cattle responsible for the largest contribution
  • Farvid, M. S., Sidahmed, E., Spence, N. D., Mante Angua, K., Rosner, B. A., & Barnett, J. B. (2021). Consumption of red meat and processed meat and cancer incidence: a systematic review and meta-analysis of prospective studies .European Journal of Epidemiology, 36(9), 937–951. https://doi.org/10.1007/S10654-021-00741-9
    • This comprehensive systematic review and meta-analysis study showed that high red meat intake was positively associated with risk of breast cancer, endometrial cancer, colorectal cancer, colon cancer, rectal cancer, lung cancer, and hepatocellular carcinoma, and high processed meat intake was positively associated with risk of breast, colorectal, colon, rectal, and lung cancers. Higher risk of colorectal, colon, rectal, lung, and renal cell cancers were also observed with high total red and processed meat consumption.
  • Feigin SV, Wiebers DO, Lueddeke G, et al. Proposed solutions to anthropogenic climate change: A systematic literature review and a new way forward. Heliyon. 2023;9(10):e20544. Published 2023 Oct 10. doi:10.1016/j.heliyon.2023.e20544
    • This review highlights one of the most important but overlooked pieces in the puzzle of solving the climate change problem – the gradual shift to a plant-based diet and global phaseout of factory (industrialized animal) farming, the most damaging and prolific form of animal agriculture. 
    • The gradual global phaseout of industrialized animal farming can be achieved by increasingly replacing animal meat and other animal products with plant-based products, ending government subsidies for animal-based meat, dairy, and eggs, and initiating taxes on such products.
  • Fry JP, Stodden B, Brace AM, Laestadius LI. A Tale of Two Urgent Food System Challenges: Comparative Analysis of Approaches to Reduce High-Meat Diets and Wasted Food as Covered in U.S. Newspapers. Sustainability. 2022; 14(19):12083.
    • “There is clear scientific evidence that diets in high-income countries need to shift away from animal-based foods and towards plant-based foods not only to reduce GHGs (greenhouse gases) to address climate change but also to reduce resource use (e.g., land, water) and pollution,” write the scientists from Maryland’s Towson University and the University of Wisconsin, “but many newspaper journalists are presenting ‘both sides’ and, therefore, covering the issue as an open debate.”
    • Forbes Article that covers the study in more plain language:  Journalists Are Making The Same Mistake With Dietary Change They Made With Climate Change: Study
  • Gardner CD, Hartle JC, Garrett RD, Offringa LC, Wasserman AS. Maximizing the intersection of human health and the health of the environment with regard to the amount and type of protein produced and consumed in the United States. Nutrition Reviews. 2019;77(4):197-215.

  • Gerber PJ, Steinfeld H, Henderson B, et al. Tackling climate change through livestock – A global assessment of emissions and mitigation opportunities. Food and Agriculture Organization of the United Nations (FAO), Rome; 2013.

  • Gibbs J, Cappuccio FP. Plant-Based Dietary Patterns for Human and Planetary Health. Nutrients. 2022;14(8):1614. Published 2022 Apr 13. doi:10.3390/nu14081614 ***
    • Current agricultural practices constitute up to 30% of global anthropogenic GHG emissions [6] and 70% of freshwater use [7], whilst occupying approximately 40% of Earth’s land [8]. Therefore, innovation within the agricultural sector has the potential to generate substantial sustainability gains.
    • Reducing red meat consumption is a major key to meeting emission targets for very high HDI countries and it would deliver substantial health co-benefits. The rate of red meat-related mortality is nearly nine times greater in very high HDI countries than in low HDI countries
    • It is time for developed nations to commit to red meat reduction targets and shift to plant-based dietary patterns. Transitioning to plant-based diets (PBDs) has the potential to reduce diet-related land use by 76%, diet-related greenhouse gas emissions by 49%, eutrophication by 49%, and green and blue water use by 21% and 14%, respectively, whilst garnering substantial health co-benefits. An extensive body of data from prospective cohort studies and controlled trials supports the implementation of PBDs for obesity and chronic disease prevention.
    • Plant-based foods have a significantly smaller footprint on the environment than animal-based foods. Even the least sustainable vegetables and cereals cause less environmental harm than the lowest impact meat and dairy products.
    • Considering the amount of land required to produce animal products, it is unsurprising that they are accountable for 67% of the deforestation caused by agriculture [9]. The destruction of ecosystems for croplands and pasturelands is the single largest factor causing species to be threatened with extinction [18]. Biodiversity is essential for the productivity and resilience of our food systems [19]. Shifting to PBDs would slow biodiversity loss substantially, thus having a protective effect on global food security.
  • Godfray HCJ, Aveyard P, Garnett T, Hall JW, Key TJ, Lorimer J, Pierrehumbert RT, Scarborough P, Springmann M, Jebb SA. Meat consumption, health, and the environment. Science. 2018 Jul 20;361(6399):eaam5324
    • “The consumption of different types of meat and meat products has substantial effects on people’s health, and livestock production can have major negative effects on the environment.”
    • Although meat is a concentrated source of nutrients for low-income families, it also enhances the risks of chronic ill health, such as from colorectal cancer and cardiovascular disease.
    • “Meat production is the single most important source of methane, which has a relatively high warming potential but a low half-life in the environment compared with that of CO2. Careful management of grassland systems can contribute to carbon storage, but the net benefits are likely to be relatively modest. Agriculture uses more freshwater than any other human activity, with nearly a third required for livestock, so meat production in water-stressed areas is a major competitor with other uses of water, including that required to maintain natural ecosystems. Meat production can be an important source of nitrogen, phosphorus, and other pollutants and affects biodiversity—in particular, through land conversion to pasture and arable feed crops.”
  •  Guglielmi, G. Eating one-fifth less beef could halve deforestation. Nature. May 4th 2022. Accessed October 2022
    •  Swapping 50% of the beef consumed per person for mycoprotein would result in a more than 80% reduction in deforestation and carbon emissions, and replacing 80% of beef with mycoprotein would eliminate about 90% of forest loss.
  • Hall J, Galarraga J, Berman I, Edwards C, Khanjar N, Kavi L, Murray R, Burwell-Naney K, Jiang C, Wilson S. Environmental Injustice and Industrial Chicken Farming in Maryland. Int J Environ Res Public Health. 2021 Oct 20;18(21):11039. doi: 10.3390/ijerph182111039.
    • The number of animals raised at industrial production facilities increased by nearly 246% between 1982 and 2002 while the total number of livestock raised in the year 2000 was equal to that of the previous 80 years
    • Due to the concentration of animals and the density of industrial farms, these operations pose threats to environmental and human health. For example, thousands of pounds of harmful emissions including volatile organic compounds (VOCs), ammonia, nitrogen, carbon dioxide, methane, particulate matter (PM), and heavy metals are emitted from CAFOs on an annual basis
    • The distribution of CAFOs and meat processing plants across Maryland may contribute to poor health outcomes in areas affected by such production, and contribute to health disparities and health inequity.
  • Hayek, Matthew N., and Rachael D. Garrett. “Nationwide shift to grass-fed beef requires larger cattle population.Environmental Research Letters 13, no. 8 (2018): 084005.
    •  If the entire U.S. beef supply were converted to grass-fed production, existing pasture land could only support 27% of current demand and, due to the necessary increased herd size, total U.S. methane emissions would rise by 8%.
  • Humpenöder, F., Bodirsky, B.L., Weindl, I. et al. Projected environmental benefits of replacing beef with microbial proteinNature 605, 90–96 (2022).
    • Life cycle assessment (LCA) studies have estimated substantial environmental benefits of MP, produced in bioreactors using sugar as feedstock, especially compared to ruminant meat
  • IPCC. 2019. Summary for Policymakers. In: Climate Change and Land: an IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems. [P.R. Shukla, J. Skea, E. Calvo Buendia, V. Masson-Delmotte, H.- O. Pörtner, D. C. Roberts, P. Zhai, R. Slade, S. Connors, R. van Diemen, M. Ferrat, E. Haughey, S. Luz, S. Neogi, M. Pathak, J. Petzold, J. Portugal Pereira, P. Vyas, E. Huntley, K. Kissick, M. Belkacemi, J. Malley, (eds.)].
    • Discusses the urgency of addressing greenhouse gas emissions from food and agriculture in order to meet climate goals.
  • Ivanovich, C.C., Sun, T., Gordon, D.R. et al. Future warming from global food consumptionNat. Clim. Chang. (2023) ***.
    • We find that global food consumption alone could add nearly 1 °C to warming by 2100. Seventy five percent of this warming is driven by foods that are high sources of methane (ruminant meat, dairy and rice). 
    • Emissions from food alone, ignoring the huge impact of fossil fuels, would push the world past the 1.5C limit.
    • Current dietary production and consumption patterns are incompatible with sustaining a growing population while pursuing a secure climate future.
    • Temperature rise could be cut by 55% by cutting meat consumption in rich countries to medically recommended levels.
    • Consumer Friendly Article detailing this report from The Guardian: Meat, dairy and rice production will bust 1.5C climate target, shows study
  • Karavasiloglou et al., Adherence to the EAT-Lancet reference diet is associated with a reduced risk of incident cancer and all-cause mortality in UK adults, One Earth (2023), https://doi.org/10.1016/j.oneear.2023.11.002
    • There is an increasing interest in plant-based diets (i.e., diets rich in plant-based products that include little, if any, animal products), due to their environmental sustainability and potential health benefits. Recently, international experts recommended a mostly plant-based, sustainable diet referred to as the “planetary health diet” 
    • In our study, people who closely followed the planetary health diet had a lower risk for cancer and mortality from all causes than those who did not closely follow the planetary health diet. Our study adds to the existing literature that following the EAT-Lancet reference diet could have benefits for non-communicable disease prevention.
  • Katz, David L (2019). Plant-Based Diets for Reversing Disease and Saving the Planet: Past, Present, and Future. Advances in Nutrition, 10(Supplement_4), S304–S307.doi:10.1093/advances/nmy124
    • The evidence is strong, consistent, and compelling that a diet of predominantly, or even exclusively, whole plant foods can promote health, selectively treat and reverse disease, and confer comparable benefit to the planet.
  • Kenny TA, Woodside JV, Perry IJ, Harrington JM. Consumer attitudes and behaviors toward more sustainable diets: a scoping review. Nutr Rev. 2023 Nov 10;81(12):1665-1679. doi: 10.1093/nutrit/nuad033. PMID: 37014671; PMCID: PMC10639109
    • Meat consumption is tied to various social values such as pleasure, identity, heritage, and cultural norms11,26,34,42,53,62 and, in many high-income countries, meat is perceived as central and necessary to ensure a “proper dinner.”
    • In high-income countries, eating less animal-based foods and more whole, plant-based food is the most beneficial action that can be adopted at the individual level to move toward a more sustainable diet.4,5,74–77 
    •  The human and planetary health risks and impacts associated with meat consumption depend on how that meat was raised, processed, and prepared.88,95 Researchers, policy-makers, and the wider public-health nutrition community must begin to account for the complexities in food systems and consider the multidimensional nature of sustainability before developing sustainability messages encouraging more sustainable diets.
    • Specific guidance on preferred foods to consume when reducing meat consumption along with recipes for plant-based meals35,39,42,44 would assist consumers in choosing and preparing more sustainable meals.
  • Kevany S. 20 meat and dairy firms emit more greenhouse gas than Germany, Britain or France. The Guardian. Published September 7, 2021.

  • Kim, B et al.  The Importance of Reducing Animal Product Consumption and Wasted Food in Mitigating Catastrophic Climate Change.  Johns Hopkins Center for a Livable Future.  Dec 2015.

    • Immediate and substantial reductions in wasted food and meat and dairy intake, particularly ruminant meat (e.g., beef and lamb), are imperative to mitigating catastrophic climate change

  • Klapp, Anna, Nico Feil, Antje Risius, A Global Analysis of National Dietary Guidelines on Plant-Based Diets and Substitutions for Animal-Based Foods, Current Developments in Nutrition, Volume 6, Issue 11, November 2022, nzac144, ***
    • “In conclusion, with global planetary and human health goals and targets falling short, it is more important than ever to ensure that FBDGs promote sustainable healthy food choices. This includes recommendations to eat fewer animal products and fostering plant-based diets and plant-based alternatives as part of their positions and food groups. Policy makers, civil society actors, and economic agents have to use all available tools to promote more sustainable, healthy, and equitable consumption patterns. FBDGs that encourage balanced food choices are also more inclusive in that they consider ethical, ecological, religious, and economic aspects that play roles in people’s everyday lives.”
  • Koch CA, Kjeldsen EW, Frikke-Schmidt R. Vegetarian or vegan diets and blood lipids: a meta-analysis of randomized trials. Eur Heart J. 2023;44(28):2609-2622. doi:10.1093/eurheartj/ehad211
    • Due to growing environmental focus, plant-based diets are increasing steadily in popularity.
    • Vegetarian and vegan diets were associated with reduced concentrations of total cholesterol, low-density lipoprotein cholesterol, and apolipoprotein B—effects that were consistent across various study and participant characteristics. Plant-based diets have the potential to lessen the atherosclerotic burden from atherogenic lipoproteins and thereby reduce the risk of cardiovascular disease.
  • Kozicka, M., Havlík, P., Valin, H. et al. Feeding climate and biodiversity goals with novel plant-based meat and milk alternatives. Nat Commun 14, 5316 (2023). https://doi.org/10.1038/s41467-023-40899-2
    • We find a substantial reduction in the global environmental impacts by 2050 if globally 50% of the main animal products (pork, chicken, beef and milk) are substituted—net reduction of forest and natural land is almost fully halted and agriculture and land use GHG emissions decline by 31% in 2050 compared to 2020.
  • Rieger, J Et al. From fork to farm: Impacts of more sustainable diets in the EU-27 on the agricultural sector. Journal of Agricultural Economics. 11 February 2023 https://doi.org/10.1111/1477-9552.12530
    • Globally, approximately 43 kg of meat and 88 kg of milk are consumed per capita per year. In Europe, these figures are twice as high, with 78 kg of meat and 216 kg of milk per capita per year. As a result, Europeans consume an average of almost 800 kcal per day from animal-based foods (FAO, 2020), which is well above nutritional recommendations (DGE, 2017) and an estimated healthy and sustainable amount of 300 kcal per day (Willett et al., 2019).
    • Although supply-side measures such as technological and management advances to improve agricultural yields, fertiliser efficiency, manure management or feed conversion rates of animals are important, they will not be sufficient to stay within planetary boundaries and reduce agricultural GHG emissions to the level required to meet the 2°C target
  • Loken B, DeClerck F. Eat Forum. Diets for a better future: Rebooting and reimagining healthy and sustainable food systems in the G20. 
  • Loken, B.  Nature-based Solutions can save the planet, but only if we change our diets too World Economic Forum Website.  2021
  • Lovegrove, J.A.O’Sullivan, D.M.Tosi, P.Millan, E.Todman, L.C.Bishop, J. et al. (2023‘Raising the Pulse’: The environmental, nutritional and health benefits of pulse-enhanced foods  Nutrition Bulletin001– 10.
    • When compared with other nutrient-dense foods like quinoa, pulse production has greater inherent sustainability due to the ability of pulses, in cooperation with symbiotic rhizobia bacteria, to biologically fix nitrogen from the atmosphere (rather than relying on fertilisation with ar-tificial nitrogen fertilisers synthesised with high-carbon footprint) to form edible protein.
    • Amongst grain legumes, faba bean has the highest yield potential (Cernay et al., 2016) and nitrogen-fixation rates (Baddeley et al., 2013) in the United Kingdom and globally, while providing valuable floral resources for a diversity of wild pollinating insects (Bailes et al., 2018). As it can be sown as a winter or spring crop and can be harvested for a long period fol-lowing maturation, it is also the most flexible pulse for a diversity of farming systems and end uses.
  • Manyi-Loh, C., Mamphweli, S., Meyer, E., Okoh, A. (2018). Antibiotic use in agriculture and its consequential resistance in environmental sources: potential public health implications. Molecules, 23(4), 795.
  • Mathur, M et al. Interventions to reduce meat consumption by appealing to animal welfare: Meta-analysis and evidence-based recommendations. Appetite Volume 164, 1 September 2021, 105277
    • Excessive consumption of meat and animal products may be deleterious to human health (with meta-analytic evidence regarding cancer (Crippa et al., 2018; Farvid et al., 2018; Gnagnarella et al., 2018; Larsson & Wolk, 2006), cardiovascular disease (Cui et al., 2019; Guasch-Ferré et al., 2019; Zhang and Zhang, 2018), metabolic disease (Fretts et al., 2015; Kim & Je, 2018; Pan et al., 2011), obesity (Rouhani et al., 2014), stroke (Kim et al., 2017), and all-cause mortality (Larsson & Orsini, 2013; Wang et al., 2016)); promotes the emergence and spread of pandemics and antibiotic-resistant pathogens (Bartlett et al., 2013; Di Marco et al., 2020; Marshall & Levy, 2011); is a major source of greenhouse gas emissions, environmental degradation, and biodiversity loss (Machovina et al., 2015; Sakadevan & Nguyen, 2017); and contributes to the preventable suffering and slaughter of approximately 500 to 12,000 animals over the lifetime of each human consuming a diet typical of his or her country
  • Matthews, C., et al. 2019. The rumen microbiome: a crucial consideration when optimizing milk and meat production and nitrogen utilization efficiency. Gut Microbes. doi.org/10.1080/19490976.2018.1505176
    • So when a ruminant has a diversely foraged diet, their microbial diversity is improved which decreases their methane production and changes the nutrient profile of their milk and meat. Furthermore, the use of antibiotics in livestock is devastating not only to the animal’s own microbiome, but also to the soil in manure and the plants, water, consumers downstream 
  • Meier, Johanna and Andor, Mark A. and Doebbe, Friederike and Haddaway, Neal and Reisch, Lucia A., Can Green Defaults Reduce Meat Consumption? (August 11, 2021). Food Policy, 110, 102298, Available at SSRN: https://ssrn.com/abstract=3903160 or http://dx.doi.org/10.2139/ssrn.3903160
    • Meat consumption and production cause a significant share of greenhouse gas (GHG) emissions in the food sector. Behavioural food policy suggests the use of defaults – i.e., pre-setting a specific choice option – as an effective demand-side instrument to reduce meat consumption.
    • We find that defaults are generally effective in nudging consumers to eat less meat. The studies’ risk of bias is assessed to be moderate. Yet, the effect size appears to be influenced by a range of moderators. In particular, the invasiveness of the default, the presentation of alternatives to choose from, and consumers’ gender and setting experience appear to moderate the effect.
  • Musicus AA, Wang DD, Janiszewski M, et al. Health and environmental impacts of plant-rich dietary patterns: a US prospective cohort study. The Lancet Planetary Health. 2022;6(11), e892-e900. https://doi.org/10.1016/S2542-5196(22)00243-1
    • Plant-based diets were associated with better environmental health and coincidently, human health. For example, less healthy diets which include refined grains and added sugars, needed more cropland and fertilizer, along with increasing the risk for cardiovascular diseases (CVD) and mortality.
    • Healthier diets that included vegetables, fruits, whole grains, nuts, legumes, vegetable oils, teas, and coffee required less cropland, irrigation water, and nitrogenous fertilizer and produced less GHG emissions
  • Poore J, Nemecek T. Reducing Food’s environmental impacts through producers and consumers. Science. 2018;360(6392):987-992. 

    • Livestock production has many negative environmental impacts, especially in terms of deforestation, greenhouse gas emissions, water use and eutrophication
  • Project Drawdown. 2020. “Table of Solutions.” February 5, 2020. https://www.drawdown.org/solutions/table-of-solutions
    • Shifting toward plant-rich diets is the third most impactful climate solution, with the potential to reduce more emissions than practices like improved manure management, improved cattle feed, managed grazing, and silvopasture can achieve combined.
  • Provenza FD, Kronberg SL, Gregorini P. Is Grassfed Meat and Dairy Better for Human and Environmental Health?. Front Nutr. 2019;6:26. Published 2019 Mar 19.

  • Putting Meat on the Table: Industrial Farm Animal Production: A Report of the Pew Commission on Industrial Farm Animal Production
  • Raising animals in an industrial system. FoodPrint. Published December 10, 2020.

  • Ranganathan J, Waite R. Sustainable diets: What you need to know in 12 charts. World Resources Institute. Published April 20, 2016.

    • It shows that just small shifts in the choices consumers make can have a huge impact in reducing agriculture’s resource use and mitigating environmental problems—the average American, for example, could cut their diet’s environmental footprint in half just by eating less meat and dairy.
    • Global average per person protein consumption exceeded dietary requirements in all regions in 2009, with each person consuming on average about 68 grams per day— one-third higher than the average daily adult requirement. 
    • Beef production requires 20 times more land and emits 20 times more greenhouse gas emissions per unit of edible protein than common plant-based protein sources such as beans, peas and lentils. Chicken and pork are more resource-efficient than beef, but still require three times more land and emit three times more greenhouse gas emissions than beans. 
  • Ranganathan J, Waite R. Animal-based Foods are More Resource-Intensive than Plant-Based Foods  – World Resources Institute Published April 20, 2016.

  • Ripple WJ, Wolf C, Gregg JW, et al. The 2023 state of the climate report: Entering uncharted territory. BioScience. 2023;0:1-10. doi:10.1093/biosci/biad080
    • Because of the growing risks of concurrent major crop losses in multiple regions of the world, adaptation-focused efforts are needed to improve crop resilience and resistance to heat, drought, and other climate stressors (Raza et al. 2019). 
    • A shift toward plant-based diets, particularly in wealthy countries, could improve global food security and help mitigate climate change (Figure 2d; Cassidy et al. 2013).
  • Ritchie, H.  Land Use Diets.  Our World in Data Website. https://ourworldindata.org/land-use-diets  Published March 04, 2021.  Accessed June 2023
    • Research suggests that if everyone shifted to a plant-based diet we would reduce global land use for agriculture by 75%. This large reduction of agricultural land use would be possible thanks to a reduction in land used for grazing and a smaller need for land to grow crops. The research also shows that cutting out beef and dairy (by substituting chicken, eggs, fish or plant-based food) has a much larger impact than eliminating chicken or fish
    • Of course the type of land used to raise cows or sheep is not the same as cropland for cereals, potatoes or beans. Livestock can be raised on pasture grasslands, or on steep hills where it is not possible to grow crops. Two-thirds of pastures are unsuitable for growing crops. This raises the question of whether we could, or should, stop using it for agriculture at all. We could let natural vegetation and ecosystems return to these lands, with large benefits for biodiversity and carbon sequestration.
    • Less than half of the world’s cereals are fed directly to humans
    • Great graphics here
  • Rust NA, Ridding L, Ward C, et al. How to transition to reduced-meat diets that benefit people and the planet. Sci Total Environ. 2020;718:137208.

    • “Overwhelming evidence shows that overconsumption of meat is bad for human and environmental health and that moving towards a more plant-based diet is more sustainable. For instance, replacing beef with beans in the US could free up 42% of US cropland and reduce greenhouse gas emissions by 334 mmt, accomplishing 75% of the 2020 carbon reduction target.”
  • Sabaté J, Soret S. Sustainability of plant-based diets: back to the future. Am J Clin Nutr. 2014; 100 Suppl 1:476S-482S.
    • “Going back” to plant-based diets worldwide seems to be a reasonable alternative for a sustainable future. Policies in favor of the global adoption of plant-based diets will simultaneously optimize the food supply, health, environmental, and social justice outcomes for the world’s population. Implementing such nutrition policy is perhaps one of the most rational and moral paths for a sustainable future of the human race and other living creatures of the biosphere that we share.
  • Sakadevan, K., & Nguyen, M.-L. (2016, December 7). Livestock production and its impact on nutrient pollution and greenhouse gas emissions. Advances in Agronomy.
    • “The intensification of livestock production led to large surpluses of on-farm nitrogen and phosphorus inputs that can potentially contribute to nonpoint source pollution of water resources in many parts of the world.”
  • Scarborough, P., Clark, M., Cobiac, L. et al. Vegans, vegetarians, fish-eaters and meat-eaters in the UK show discrepant environmental impacts. Nat Food 4, 565–574 (2023). https://doi.org/10.1038/s43016-023-00795-w ***
    • There is a strong relationship between the amount of animal-based foods in a diet and its environmental impact, including GHG emissions, land use, water use, eutrophication & biodiversity. Any reduction in animal foods in the diet has a significant beneficial impact on all aspects of planetary health examined. Lower meat diets (<50g/day) have half the CO2 impact of high meat diets & vegan diets have half the impact of lower meat diets. 
    • We link dietary data from a sample of 55,504 vegans, vegetarians, fish-eaters and meat-eaters with food-level data on greenhouse gas emissions, land use, water use, eutrophication risk and potential biodiversity loss from a review of 570 life-cycle assessments covering more than 38,000 farms in 119 countries.
    • Despite substantial variation due to where and how food is produced, the relationship between environmental impact and animal-based food consumption is clear and should prompt the reduction of the latter.
    • The UK has a legal commitment to a 78% reduction in GHG emissions by 2035 compared to 199017 and of halting biodiversity loss by 203018. Our results suggest that much bigger reductions can be achieved by increasing the uptake of plant-based diets, which aligns with other results from this field7,8,11.
  • Schiermeier Q. Eat less meat: Un climate-change report calls for change to human diet. Nature. 2019;572(7769):291-292. doi:10.1038/d41586-019-02409-7
    • Specifically decreasing U.S. beef consumption by  90% of and replacing 50% of consumption of other meats with plant-based options could prevent over 2 billion tons of greenhouse gas emissions from being emitted by 2030. 
  • Semba, Kim, et al. Major Health Gains and Carbon Savings Possible from a Shift to Plant-based Diets. Nature Food. 2020

    • “Overall the adoption of a healthy, plant-based diet around the world would significantly reduce greenhouse gas emissions, and improve health,”
    • “However, in some poor countries where people’s diets are really lacking in vital nutrients, achieving a healthy diet would actually lead to an increase in carbon emissions unless additional action were taken to mitigate against this.”
  • Shah UA, Merlo G. Personal and Planetary Health—The Connection With Dietary Choices. JAMA.2023;329(21):1823–1824. doi:10.1001/jama.2023.6118
    • The world now produces more than 3 times the meat and more than double the milk as it did 50 years ago. This has well-established negative effects on the environment, including the destruction of native ecosystems to support livestock grazing and increased cultivation of animal feedstocks.
    • Livestock and its supply chain also contribute to greenhouse gas emissions, such as carbon dioxide, methane, and nitrous oxide. Livestock farming accounts for 50% of methane and 60% of nitrous oxide emissions, which respectively have 25 and 298 times the global warming potential of carbon dioxide on a mass basis.
    • Additionally, most nitrogen pollution in wastewater is due to animal-based protein sources and inefficient agricultural practices, which lead to acid rain and toxic algal blooms that cause dead zones of aquatic life.
    • “Our dietary choices have broad and far-reaching impacts. It is no longer just about human health but planetary health as well. Advocating for a reduction in our consumption of animal foods needs to become a central part of climate change education, discussion, and solution. Switching to a plant-based diet is likely one of the fastest and easiest paths to turning the ship.  (Comment from Sharon Mcdowell-Larsen, PhD | Center for Creative Leadership)
  • Shi W, Huang X, Schooling CM, Zhao JV. Red meat consumption, cardiovascular diseases, and diabetes: a systematic review and meta-analysis. Eur Heart J. 2023 Jul 21;44(28):2626-2635.
    • Unprocessed and processed red meat consumption are both associated with higher risk of CVD, CVD subtypes, and diabetes, with a stronger association in western settings but no sex difference. Better understanding of the mechanisms is needed to facilitate improving cardiometabolic and planetary health.
  • Son, J., Miranda, M. L., & Bell, M. L. (2021). Exposure to concentrated animal feeding operations (CAFOs) and risk of mortality in North Carolina, USA. Science of the Total Environment, 799(149407). 
  • Springmann M, Godfray HCJ, Rayner M, Scarborough P. Analysis and valuation of the health and climate change cobenefits of dietary change. Proceedings of the National Academy of Sciences of the United States of America. 2016;113(15):4146-4151. doi:10.1073/pnas.1523119113
    • The food system is responsible for more than a quarter of all greenhouse gas (GHG) emissions (1), of which up to 80% are associated with livestock production (2, 3). The aggregate dietary decisions we make thus have a large influence on climate change. High consumption of red and processed meat and low consumption of fruits and vegetables are important diet-related risk factors contributing to substantial early mortality in most regions while over a billion people are overweight or obese (4). Without targeted dietary changes, the situation is expected to worsen as a growing and more wealthy global population adopts diets resulting in more GHG emissions (5) and that increase the health burden from chronic, noncommunicable diseases (NCDs) associated with high body weight and unhealthy diets (6).
    • Transitioning towards more plant-based diets in line with WHO and other international dietary guidelines could decrease global mortality, shrink the global food gap and substantially reduce diet-related GHG emissions.
  • Sranacharoenpong K, Soret S, Harwatt H, Wien M, Sabaté J. The environmental cost of protein food choices. Public Health Nutr. 2015;18(11):2067-2073. doi:10.1017/S1368980014002377
    • A study from 2015 found that producing 1 kg of protein from kidney beans required approximately eighteen times less land, ten times less water, nine times less fuel, twelve times less fertilizer and ten times less pesticide in comparison to producing 1 kg of protein from beef.
  • Średnicka-Tober D, Barański M, Seal C. Composition differences between organic and conventional meat: a systematic literature review and meta-analysis. Br J Nutr. 2016;115(06):994–1011. +  Średnicka-Tober D, Barański M, Seal CJ. 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. 2016;115(06):1043–1060.
    • organic meat, milk, and dairy products have approximately higher concentrations of nutritionally-desirable omega-3 fatty acids; intakes of very long chain omega-3 fatty acids in Western diets 
    • organic milk was reported to contain higher levels of total conjugated linoleic acid (CLA), higher iron and α-tocopherol concentrations, which are all considered to be nutritionally desirable, although the evidence for health benefits of CLA is mainly from in vitro and animal studies
    • conventional meat has slightly, but significantly higher concentrations of the saturated fatty acids myristic- and palmitic acid, which were linked to an increased risk of cardiovascular disease
  • Sun, Z., Scherer, L., Tukker, A. et al. Dietary change in high-income nations alone can lead to substantial double climate dividend. Nat Food 3, 29–37 (2022).

    • A dietary shift from animal-based foods to plant-based foods in high-income nations could reduce greenhouse gas emissions from direct agricultural production and increase carbon sequestration if resulting spared land was restored to its antecedent natural vegetation
    •  Dietary change could reduce annual agricultural production emissions of high-income nations’ diets by 61% while sequestering as much as 98.3 (55.6–143.7) GtCO2 equivalent, equal to approximately 14 years of current global agricultural emissions until natural vegetation matures.
  • Sun, Z., Scherer, L., Zhang, Q. et al. Adoption of plant-based diets across Europe can improve food resilience against the Russia–Ukraine conflictNat Food 3, 905–910 (2022).
    • A transition towards the EAT-Lancet’s planetary health diet in the European Union and the United Kingdom alone would almost compensate for all production deficits from Russia and Ukraine while yielding improvements in blue water use, greenhouse gas emissions  and carbon sequestration
  • Sustainable Agriculture: Beef. World Wildlife Fund.  Website.  https://www.worldwildlife.org/industries/beef. Accessed Sept 2022
    • “Beef production has a considerable effect on climate change due to emissions of greenhouse gases such as methane, nitrous oxide and carbon dioxide. Research shows that ruminant livestock account for between 7% and 18% of global methane emissions from human-related activities.”
  • Twine, R. Emissions from Animal Agriculture—16.5% Is the New Minimum Figure Sustainability 202113(11), 6276;  Published: 2 June 2021
    •  Subsequent work such as the EAT-Lancet commission [7] calls for substantial reductions in meat consumption within a co-benefit framing of improving human health and achieving emissions reductions (as well as other concerns including biodiversity and water conservation). The commission argued that transitioning to more sustainable diets is necessary to successfully meet the mitigation targets of the Paris Agreement and the United Nations’ Sustainable Development Goals (SDGs)
  • Tzeng HT, Chyuan IT, Chen WY. Shaping of Innate Immune Response by Fatty Acid Metabolite Palmitate. Cells. 2019;8(12):1633
    • Corn fed beef is higher in palmitic acid which is associated with inflammation and obesity
  • United Nations Environment Programme and Climate and Clean Air Coalition. 2021. Global Methane Assessment: Benefits and Costs of Mitigating Methane Emissions. Nairobi: United Nations Environment Programme.
  • The White House. 2021. The White House Office of Domestic Climate Policy, U.S. Methane Emissions Reduction Action Plan 6.   (citing EPA, Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2019 (2021)).
    • Animal agriculture is the largest source of methane in the U.S., driven by enteric fermentation from cattle.
  • Willet, W et al. Food in the Anthropocene: the EAT–Lancet Commission on healthy diets from sustainable food systems  THE LANCET COMMISSIONS| VOLUME 393, ISSUE 10170P447-492, FEBRUARY 02, 2019
    • Food systems have the potential to nurture human health and support environmental sustainability; however, they are currently threatening both. Providing a growing global population with healthy diets from sustainable food systems is an immediate challenge. 
    • Because much of the world’s population is inadequately nourished and many environmental systems and processes are pushed beyond safe boundaries by food production, a global transformation of the food system is urgently needed.
  • Willet, W. Food Planet, Health.  Healthy Diets From Sustainable Food Systems.  E.A.T. EAT-Lancet Commission Summary Report, 2019
    • Food is the single strongest lever to optimize human health and  environmental sustainability on Earth.
    • A radical transformation of the global food system is urgently needed. Without action, the world risks failing to meet the UN Sustainable Development Goals (SDGs) and the Paris Agreement, and today’s children will inherit a planet that has been severely degraded and where much of the population will increasingly suffer from malnutrition and preventable disease.
    • A diet rich in plant-based foods and with fewer animal source foods confers both improved health and environmental benefits.
    • Operating outside this space for any Earth system process (e.g. high rates of biodiversity loss) or food group (e.g. insufficient vegetable intake) increases the risk of harm to the stability of the Earth system and human health.
    • This includes a more than doubling in the consumption of healthy foods such as fruits, vegetables, legumes and nuts, and a greater than 50% reduction in global consumption of less healthy foods such as added sugars and red meat (i.e. primarily by reducing excessive consumption in wealthier countries). However, some populations worldwide depend on agropastoral livelihoods and animal protein from livestock
  • Wolf, J., Asrar, G.R. & West, T.O. Revised methane emissions factors and spatially distributed annual carbon fluxes for global livestock. Carbon Balance Manage 12, 16 (2017). https://doi.org/10.1186/s13021-017-0084-y
    • In this study, we update information for cattle and swine by region, based on reported recent changes in animal body mass, feed quality and quantity, milk productivity, and management of animals and manure. We then use this updated information to calculate new livestock methane emissions factors for enteric fermentation in cattle, and for manure management in cattle and swine.
    • Our results suggest that livestock methane emissions, while not the dominant overall source of global methane emissions, may be a major contributor to the observed annual emissions increases over the 2000s to 2010s.
  • Wong C. Eat less meat: will the first global climate deal on food work?Nature. Published online December 8, 2023. doi:10.1038/d41586-023-03960-0
    • Making food systems more sustainable is crucial to keeping alive the dream of limiting global warming to 1.5°C above pre-industrial levels, agreed at COP21 in Paris in 2015. Getting food from farm to food-table accounts for around a third of global greenhouse gas emissions, according to a 2021 study by Monica Crippa and Adrian Leap of the European Commission’s Joint Research Centre in Ispra, Italy.
    • The declaration is not legally binding. It also fails to mention the role of fossil fuels in food systems such as that used to transport food as well as in powering farm machinery and refrigeration.
    • Halving food loss and waste could remove around one-quarter of greenhouse gas emissions from the food system, the team has estimated.
    • Meat, dairy and other animal products generate more emissions than other food types such as fruit and vegetables. Halving meat consumption globally could reduce food system emissions by nearly one-quarter if the calories were replaced by other food types, according to the authors of the Nature Food study.
  • Xu, X., Sharma, P., Shu, S. et al. Global greenhouse gas emissions from animal-based foods are twice those of plant-based foods. Nat Food 2, 724–732 (2021).
    • More than half of those emissions (from  the food system’s global greenhouse-gas emission) are driven by livestock farming (57%)
    • We define animal-based food emissions as the emissions from all subsectors caused by or associated with the production and consumption of animal-based food (Methods and Table 1). I
    • We include LUC  (Land use change) emissions from the expansion of agricultural land (crop plus grazing land) and from beyond farm-gate emissions under the life-cycle assessment (LCA) framework of Poore and Nemecek5 to include emissions from fertilizers, pesticides and pre-plate product processing and transportation.
    • Consumer-friendly article from Scientific American: Thompson A. Here’s how much food contributes to climate change: Animal-based foods produce about twice the emissions of plant-based ones, a new comprehensive study finds.  September 2021.

OPTIONS FOR REPLACING ANIMAL-BASED FOODS WITH PLANT-BASED MEATS

  • Humpenöder, F., Bodirsky, B.L., Weindl, I. et al. Projected environmental benefits of replacing beef with microbial protein. Nature 605, 90–96 (2022).
    • Our model projections show that substituting 20% of per-capita ruminant meat consumption with MP globally by 2050 (on a protein basis) offsets future increases in global pasture area, cutting annual deforestation and related CO2 emissions roughly in half, while also lowering methane emissions. 

Additional Resources to Explore

Saving the Planet with your Fork

Saving the Planet with your Fork

While not everyone always has a choice in what they eat and buy, for those who do, what goes on the menu, plate or shopping cart can make a difference for our environment.   This doesn’t require perfection or a complete 180 in dietary habits.  But since our...

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