Importance of considering environmental sustainability in dietary guidelines

Abstract

The composition of diets and the quality of foods we eat have direct effects on our health and wellbeing. The indirect health effects caused by environmental changes associated with the processes of producing the foods for the diets, are less recognised. Because the aim of national dietary guidelines is to provide advice for constructing healthy diets, the guidelines should arguably consider both direct and indirect health consequences of the nutritional recommendations. Food systems are one of the main contributors to environmental changes such as climate change, land use, and water and air pollution, accounting for about 19–29% of all anthropogenic greenhouse gas emissions1Vermeulen SJ Campbell BM Ingram JSI Climate change and food systems.Ann Rev Environ Res. 2012; 37: 195-222Crossref Scopus (899) Google Scholar and having a substantial impact on most planetary boundaries that determine the safe operating space for humanity.2Rockström J Williams J Daily G et al.Sustainable intensification of agriculture for human prosperity and global sustainability.Ambio. 2017; 46: 4-17Crossref PubMed Scopus (347) Google Scholar At the same time, food systems are also heavily affected by environmental changes that can have major health implications because of reductions in yields and alterations of the nutritional composition of crops if adequate adaptation technologies are not developed.3Tuomisto HL Scheelbeek PF Chalabi Z et al.Effects of environmental change on agriculture, nutrition and health: a framework with a focus on fruits and vegetables.Wellcome Open Res. 2017; 2: 21PubMed Google Scholar, 4Scheelbeek PFD Bird FA Tuomisto HL et al.Effect of environmental changes on vegetable and legume yields and nutritional quality.Proc Natl Acad Sci USA. 2018; 115: 6804-6809Crossref PubMed Scopus (62) Google Scholar Ensuring food and nutrition security in the future requires urgent actions for both mitigation and adaptation to environmental changes in all parts of food systems. The study in The Lancet Planetary Health by Nicole Blackstone and colleagues5Blackstone NT El-Abbadi NH McCabe MS Griffin TS Nelson ME Linking sustainability to the healthy eating patterns: a systematic analysis of the Dietary Guidelines for Americans.Lancet Plan Health. 2018; 2: e344-e352Summary Full Text Full Text PDF PubMed Scopus (49) Google Scholar contributes to this important debate by highlighting the environmental footprint of three different diets recommended in the 2015–20 Dietary Guidelines for Americans:6US Department of Health and Human Services and US Department of AgricultureDietary guidelines for Americans 2015–2020, eight edition.http://health.gov/dietaryguidelines/2015/guidelines/Date: 2015Date accessed: July 7, 2018Google Scholar the healthy US-style, healthy Mediterranean-style, and healthy vegetarian dietary patterns. By assessing six categories of environmental impacts (climate change, land use, water depletion, freshwater eutrophication, marine water eutrophication, and particulate matter or respiratory inorganics), they established that the healthy vegetarian diet produced a 42–84% lower burden than the other two diets for all impacts except water depletion, which was similar between the three diets. Blackstone and colleagues5Blackstone NT El-Abbadi NH McCabe MS Griffin TS Nelson ME Linking sustainability to the healthy eating patterns: a systematic analysis of the Dietary Guidelines for Americans.Lancet Plan Health. 2018; 2: e344-e352Summary Full Text Full Text PDF PubMed Scopus (49) Google Scholar call for better incorporation of environmental sustainability aspects into future dietary guidelines, because the 2015–20 Dietary Guidelines for Americans considered sustainability aspects to be beyond the scope of the guidelines. By contrast, the Nordic nutritional recommendations7NordenNordic Nutrition Recommendations 2012. Integrating nutrition and physical activity.https://www.norden.org/en/theme/former-themes/themes-2016/nordic-nutrition-recommendation/nordic-nutrition-recommendations-2012Date: 2014Date accessed: July 7, 2018Google Scholar adopt a more holistic view by including guidance for reducing the environmental impact of diets, such as to choose meat and fish with low environmental impacts, replace livestock products with plant-based protein sources, consume seasonal fruits and vegetables, and reduce food waste.7NordenNordic Nutrition Recommendations 2012. Integrating nutrition and physical activity.https://www.norden.org/en/theme/former-themes/themes-2016/nordic-nutrition-recommendation/nordic-nutrition-recommendations-2012Date: 2014Date accessed: July 7, 2018Google Scholar Additional guidelines for optimising the health and environmental outcomes of diets are indeed needed because diets recommended in healthy eating guidelines could have even greater environmental impacts than the current average diet. Birney and colleagues8Birney CI Franklin KF Davidson FT Webber ME An assessment of individual foodprints attributed to diets and food waste in the United States.Environ Res Lett. 2017; 12: 105008Crossref Scopus (37) Google Scholar showed that switching from the current average American diet to the healthy US-style diet recommended in the Dietary Guidelines for Americans6US Department of Health and Human Services and US Department of AgricultureDietary guidelines for Americans 2015–2020, eight edition.http://health.gov/dietaryguidelines/2015/guidelines/Date: 2015Date accessed: July 7, 2018Google Scholar would increase energy use, blue water footprint, and fertiliser use. This would be mainly caused by the recommendation to substantially increase the intake of fruits, vegetables, and dairy products. However, the protein food group recommendations, including red meat, poultry, and seafood produced a similar impact to that of the current average US diet. Much evidence has shown that plant-based diets have both health and environmental benefits.9Aleksandrowicz L Green R Joy EJ Smith P Haines A The impacts of dietary change on greenhouse gas emissions, land use, water use, and health: a systematic review.PLoS One. 2016; 11: e0165797Crossref PubMed Scopus (313) Google Scholar Therefore, incorporation of sustainability in the dietary recommendations would require inclusion of advice to replace livestock products with plant-based alternatives. One of the major challenges of switching to plant-based diets is changing the consumer preferences, because meat is an important part of American food culture. Developing better alternatives to livestock products can improve the attractiveness of reducing the intake of animal-based foods. Cellular agriculture, for example, uses cell-culture technologies for producing agricultural products, and therefore, provides possibilities to produce foods that closely imitate livestock products.10Stephens N Dunsford I Di Silvio L Ellis M Glencross A Sexton A Bringing cultured meat to market: technical, socio-political, and regulatory challenges in cellular agriculture.Trends Food Sci Technol. 2018; 78: 155-166Crossref PubMed Scopus (137) Google Scholar Cultured meat (ie, in-vitro meat, clean meat, or laboratory-grown meat) is one of the applications of cellular agriculture and is produced by cultivating livestock cells in a bioreactor in nutrition medium. Cellular agriculture also involves processes in which microbes, such as yeast, fungus, or bacteria synthesise proteins (eg, milk or egg albumin) that are used as food ingredients. Some studies have indicated that cellular agriculture could have major environmental benefits over livestock production if the processes could be efficiently scaled up.11Tuomisto HL de Mattos MJ Environmental impacts of cultured meat production.Environ Sci Technol. 2011; 45: 6117-6123Crossref PubMed Scopus (261) Google Scholar, 12Mattick CS Landis AE Allenby BR Genovese NJ Anticipatory life cycle analysis of in vitro biomass cultivation for cultured meat production in the United States.Environ Sci Technol. 2015; 49: 11941-11949Crossref PubMed Scopus (106) Google Scholar Further research is needed to establish the consequential environmental impacts of dietary changes. A major reduction in livestock production would release large areas of land for other uses, as production of animal-based protein requires more land than plant-based protein. Therefore, the total consequential impacts of the dietary switch would depend on the way the released land would be used. The integration of sustainability in all policies is essential to minimise environmental challenges. Recommendations for healthy diets are not complete if they ignore the indirect health impacts caused by environmental changes associated with food production and consumption. In addition to dietary change, improvements in the sustainability of food systems require further efforts for reducing the environmental burden of agriculture and food production, decreasing food waste, and improving the adaptation capacity of food systems to environmental changes. I declare no competing interests. Linking sustainability to the healthy eating patterns of the Dietary Guidelines for Americans: a modelling studyThe recommended patterns in the Dietary Guidelines for Americans might have starkly different impacts on the environment and other dimensions of human health beyond nutrition. Given the scale of influence of the Dietary Guidelines for Americans on food systems, incorporating sustainability into their development has the potential to have great benefit in terms of long-term food security. Full-Text PDF Open Access