Planetary health and sustainable and ethical human diets

Authors: Robyn Alders1, Brigitte Bagnol1, David Guest2, Richard Kock3, Jonathan Rushton4
Author Affiliations: 1School of Veterinary Science, Charles Perkins Centre, University of Sydney; 2Plant Breeding Institute, School of Life and Environmental Sciences, The University of Sydney; 3Wildlife Health and Emerging Diseases, Royal Veterinary College, London; 4Agricultural Economics and Food Systems, Liverpool University

Supplying reliable, adequate, ethical and safe nutrition for more than 8 billion people and more than 27 billion dependent livestock predicted by 2050 whilst sustaining biodiversity are among the most important and complex of human responsibilities. Globally, many food systems adversely affect the ecosystem and are driving biodiversity decline (including soil, animals and plants) through direct impacts and human diets are compromised , through under- or over- nutrition, and the risk of zoonotic disease. Poor community health and nutrition further compound low agricultural productivity and poverty at local, regional and national levels. The growing global population and associated environmental pressures necessitate a realignment of agriculture towards more specifically defined human nutrition and food safety needs, providing sufficient nutritious food without excessive or poorly targeted production. This realignment must occur at a time when i) support for agricultural research and development, essential to overcoming the inadequacies of the current system, has declined markedly and ii) agricultural producers are learning how to cope with the impact of climate change and weather variability on their production systems. This paper discusses key challenges and potential solutions associated with i) increasing food production (by providing diets tailored to individuals according to their life stages and cuisines of sub-populations, producing nutritionally rich foods, increasing dietary diversity and empowering women), ii) decreasing food wastage (by decreasing post-harvest losses, increasing the purchase of appropriate quantities of nutritious food, increasing food safety and decreasing nutrient loss) and iii) changing dietary habits and addressing population growth issues. How can expertise in health, agriculture, environmental and social sciences come together to provide efficient solutions to the identified challenges? Farmers and others involved in the food supply chain can help to achieve this goal locally, while also contributing to research and policy that informs these efforts on a global level.

Optimization of diets to reduce water use and improve population health in India

Authors: James Milner1, Rosemary F Green1, Edward Joy1, Francesca Harris1, Lukasz Aleksandrowicz1, Andy Haines1, Alan D Dangour1
Author Affiliations: 1London School of Hygiene & Tropical Medicine

Background: Factors including rapid population growth and environmental change may reduce water availability in India, placing pressure on the food system and affecting population health. This study aimed to identify realistic changes to Indian diets which would reduce future per capita demand for blue water (irrigation) and be beneficial to health.

Methods: Using data from the Indian Migration Study (IMS), we identified five typical dietary patterns based on 36 food groups. For each food group, we estimated its nutritional composition, blue water footprint and greenhouse gas (GHG) emissions. We then optimized the diets to reduce blue water use and achieve WHO nutritional requirements with minimal deviation from existing consumption. A life table method was used to estimate the health effect which would result from adoption of the optimized diets.

Findings: The optimized diets generally featured increased consumption of fruits and vegetables. There were decreases in consumption of wheat, dairy, eggs and poultry, and switches to fruits with lower blue water footprints. Adoption of the optimized diets would be broadly beneficial for health in India, with an overall mean of 6,800 QALYs gained per 100,000 population over 40 years (95% CI 1,600–13,100). The largest benefits would be for coronary heart disease and (to a lesser extent) stroke and cancers. As an incidental benefit, the diets would also be lower in GHG emissions. In the short term, these multiple benefits could be achieved with relatively little change to current dietary patterns. However, because of population growth, by mid-century the required changes for some patterns would be large.

Interpretation: This study demonstrates that Indian dietary patterns can potentially be modified to address reductions in blue water availability with resulting modest improvement in the health of the population. Complementary strategies, including more efficient production, are likely to be important in the longer term.

Impacts on greenhouse gas emissions and water use of Indian diets

Authors: Edward Joy1, James Milner1, Sylvia Vetter2, Francesca Harris1, Sutapa Agrawal3, Lukasz Aleksandrowicz1, Jennie Macdiarmid2, Jon Hillier2, Pete Smith2, Andy Haines1, Alan Dangour1
Author Affiliations: 1London School of Hygiene & Tropical Medicine; 2University of Aberdeen; 3Public Health Foundation of India

Background: India is the world’s third largest contributor to greenhouse gas (GHG) emissions and the world’s largest user of groundwater. This is not only due to its large population but also the rapid pace of development and dietary change, which has resulted in diverse diets being consumed by different population groups. This study aimed to quantify the GHG emissions in carbon dioxide equivalent (CO2e) and water usage in litres (L) associated with typical dietary patterns in India.

Methods: The GHG emissions and water use of five typical and distinct dietary patterns were quantified using estimates taken from previous studies, and based on the LCA model for GHG emissions and the Water Footprint (WF) Assessment for water use. The dietary patterns were identified from the Indian Migration Study (IMS), a large adult population sample in India, and were named on the basis of the dominant staple grain and one other identifying feature: Rice & low energy, Rice & fruit, Wheat & pulses, Wheat, rice & oils, Rice & meat. Mixed effects regression models were used to quantify the change in environmental impacts that would occur for individuals switching between dietary patterns.

Results: Overall across all dietary patterns, the GHG emissions from Indian diets were 3.6kg CO2e/capita/day (mean ± standard deviation), the green WF (from precipitation) was 2,531L/capita/day and the blue WF (from ground and surface water) was 737L/capita/day. However, there was substantial variability between dietary patterns: the rice-based patterns had higher GHG emissions and green WFs per calorie, while the wheat-based patterns had slightly higher blue WFs per calorie. Switching from the Rice & low energy diet to the Rice & meat pattern would result in a 0.59kg (15%) increase in GHG emissions, a 536L (24%) increase in green WF and a 109L (19%) increase in blue WF. By contrast, switching to the Wheat, rice & oils pattern would result in a 0.82kg (20%) decrease in GHG emissions and a 364L (17%) decrease in green WF, but a 302L (53%) increase in blue WF.

Discussion: These are the first estimates of environmental impacts from distinct dietary patterns in India. Overall, Indian diets were lower in both GHG emissions and green WFs although higher in blue WFs than diets in high income countries. However, the rice-based patterns were found to have much higher environmental impacts than the wheat-based patterns. As Indian diets continue to transition, it is likely that more people will switch their diets from the most traditional pattern identified (the Rice & low energy) pattern to one of the other rice- or wheat-based patterns. Switching to one of the wheat-based patterns identified would reduce dietary GHG emissions and green WF, but increase blue WF, which may not be desirable in a country already suffering groundwater shortages. Future policies on food will need to balance the various environmental impacts of different diets as well as the possible health implications, and may also need to take into account regional variations in both environmental conditions and cultural diet preferences.

The Water Footprint of Diets in India

Authors: Francesca Harris1, Rosemary Green1, Edward Joy1, Andy Haines1, Alan Dangour1
Author Affiliations: 1London School of Hygiene & Tropical Medicine

Background: India’s fresh water use is dominated by agriculture, but diminishing groundwater supply and potential changes to rainfall threaten future food production. Quantifying the water use of food can inform policy makers and help plan for future water scenarios. This includes investigating water use of food types, diets and differences between socio-demographic groups. This research aims to provide an initial insight into the water use of diets in India using the water footprint (WF) assessment method.

Methods: Dietary data from the Indian Migration Study were linked to state level WF data in India to quantify the water use of diets. Variations in the WFs of food items were explored, and associations between diet’s blue WF (i.e. irrigation) and socio-demographic characteristics were assessed.

Findings: The food items with the highest blue WF (per tonne) in India are nuts and seeds, vegetable oils and meat products, whereas the foods with the lowest blue WF in India are mostly fruits and vegetables. However, there are wide spatial variations in the food and animal product WFs. The average total WF of diets was roughly 20% blue WF, and the rest consisting of green water consumption (i.e. rainfall). Wheat is the highest contributor to the average dietary blue WF, followed by rice. The dietary blue water footprint was associated with a number of factors, with region being the greatest predictor of dietary blue WF. Blue WFs of diets of was highest in northern participants and lowest in southern, largely due to greater wheat consumption in the north. The WF of urban diets was greater than that of rural diets, even after adjusting for total calories. Higher standard of living was also associated with greater dietary blue WF, in both calories and composition.

Interpretation: The WF of diets in India varies between social and geographical groups. Further study should consider local impact by combining WFs with data on water availability and scarcity. Optimisation techniques can be used to establish trade-offs and co-benefits for sustainable diet recommendations.

Small-scale poultry ownership is positively associated with improved height-for-age in young children in the semi-arid central zone of Tanzania

Authors: Julia de Bruyn1
Author Affiliations: 1Sydney School of Veterinary Science & Charles Perkins Centre, The University of Sydney

Indigenous chickens are kept in small flocks in many resource-limited environments, where they offer a comparatively accessible form of livestock ownership for poor households. Scavenging poultry are able to transform available feed sources into highly nutritious foods for human consumption, with particular value for supporting intrauterine and early postnatal growth and development. Low input requirements and frequent ownership by women make the potential contributions of poultry to household income and diets particularly significant.

This longitudinal study was conducted in eight villages in Manyoni District, within the semi-arid central zone of Tanzania, from May 2014. Annual rainfall of 360 mm and 680mm was recorded in the study sites over consecutive years, with marked variation in the timing and number of rain days. A total of 510 children under 24 months of age were enrolled via random selection in a study aiming to assess the impact of community-based chicken vaccination programs and strategic improvements to crop systems on children’s diets and growth.

Six- to twelve-monthly data on health and nutrition, household characteristics and livestock ownership, and fortnightly data on chicken ownership and child illness were jointly analysed to assess their association with height-for- age Z-scores (HAZ) in children. Within a multivariable model, children from households owning chickens were found to have significantly higher (improved) HAZ than those from households without chickens (-1.78 vs. -1.93; p=0.005). Separate analysis found no association of diarrhoea in children with chicken ownership, or with the practice of keeping chickens within human dwellings overnight.

Scavenging poultry systems, which utilise available environmental resources and require minimal labour or financial inputs, have the ability to increase the resilience of smallholder farmers in times of climate variability. A positive association between chicken ownership and children’s growth supports the potential for poultry-based interventions to improve nutrition in resource-poor communities.

Understanding use of local food and nutritional resources: translation from research to action

Authors: Johanna Wong1, Brigitte Bagnol1,2,3, Heather Grieve4, Joanita Jong5, Antonino do Karmo5, Mu Li6, Robyn Alders1,2
Author Affiliations: 1Faculty of Veterinary Science and the Charles Perkins Centre, The University of Sydney, Camperdown, Australia; 2International Rural Poultry Centre, Kyeema Foundation, Brisbane, Australia and Maputo, Mozambique; 3Witwatersrand University, Johannesburg, South Africa; 4Independent nutrition consultant, Dili, Timor-Leste; 5Department of Veterinary Services, Ministry of Agriculture and Fisheries, Dili, Timor-Leste; 6School of Public Health, The University of Sydney, Camperdown, Australia.

Current research in six rural villages in Timor-Leste investigates the relationship between food consumption, particularly high quality foods such as village chickens and eggs, and nutritional status of mothers and infants and young children (IYC). Village chickens have high genetic biodiversity, are adaptive to harsh environments, and may have increased importance as a food source in the face of environmental change. Combined qualitative and quantitative methods found that chickens are among the most frequently kept, sold and slaughtered livestock, therefore having great potential to contribute to dietary quality. However, high disease rates limit chicken productivity.

In these villages, IYC have high rates of stunting, indicative of chronic nutritional inadequacy, and low rates of animal-source food (ASF) consumption. Factors affecting maternal food choice for IYC include limited nutrition knowledge, time and cost constraints, children’s taste preferences, and perceived age appropriateness of foods. Mothers felt that meat is not an appropriate food for IYC, while eggs are highly acceptable by both mothers and IYC. Eggs, however, are needed to hatch replacement stock due to high chicken mortality, limiting the availability for consumption. In households with good poultry management strategies, a higher level of chicken production allows daily egg consumption by IYC. These findings suggest that improving village chicken production and nutrition education can realistically increase ASF consumption, and therefore dietary quality, in IYC.

The Timorese and Australian governments are working to improve village chicken production through decreasing chicken mortality due to Newcastle disease. Additionally, the Timorese government has launched a public campaign to raise awareness of the benefits of egg consumption in pregnant and breastfeeding mothers, as well as IYC, and plan to pilot prolonged promotion of egg consumption in targeted villages. Effective collaboration between researchers, governments and policy makers can accelerate improvements in nutritional status of mothers in IYC.

Soil-crop element transfers and their importance for micronutrient nutrition

Authors: Edward Joy1, Diriba B Kumssa2, Allan DC Chilimba3, Michael J Watts4, Scott D Young2, E Louise Ander4, Martin R Broadley2
Author Affiliations: 1Department of Population Health, London School of Hygiene & Tropical Medicine, 2University of Nottingham; 3Malawi Ministry of Agriculture, Irrigation and Water Development; 4British Geological Survey

Micronutrient deficiencies (MNDs), including calcium, iodine, iron, selenium and zinc (Ca, I, Fe, Se and Zn), are widespread globally and underlie a significant disease burden. In typical subsistence food systems of sub-Saharan Africa (SSA), the composition of locally-available staple crops is a major determinant of dietary micronutrient supplies.

Pilot studies in Malawi demonstrated substantial variation in Fe, Se and Zn status of women that was linked to soil factors including pH and presence of aluminium and Fe-oxides (Sci Rep 3:1425, 2013), indicating the importance of locally-relevant crop composition data. Subsequently, a national picture of dietary MNDs was constructed using food supply data derived from the Third Integrated Household Survey and food composition data generated through soil-crop sampling. MND risks were analysed in terms of socioeconomic and spatial factors (BMC Nutr, 1:42, 2015).

Diets were deficient in energy, Ca, Se and/or Zn supplies for >50% of households, but supply of Fe was adequate for >80% of households. Adequacy of I was contingent on the use of iodised salt. Over 80% of the poorest households had inadequate dietary supplies of Ca and Zn compared to <30% of the wealthiest households; >80% of rural households living on low-pH soils had inadequate dietary Se supplies compared to 55% on calcareous (high pH) soil types.

MNDs are likely to be widespread in Malawi and other countries in SSA. Spatially-informed integration of large-scale dietary and crop composition datasets offers a novel methodology to explore the causes and prevalence of MNDs. Furthermore, understanding the influence of soil factors on dietary MN supplies is important for modelling studies which aim to forecast future risks of MNDs considering changes in diets, agronomy (including biofortification), climate and soil quality.

Fighting climate change with the power of water

Authors: Ashley Aimone1, Paula Braitstein1, Donald Cole1, Andrea Cortinois1
Author Affiliations: 1Dalla Lana School of Public Health, University of Toronto

As the era of the Anthropocene unfolds, and climate/environmental change (CEC) becomes more of a concern, there is also a large and persistent gap between what is known about the future of the planet’s health and what the global health community is presently doing about it. Water insecurity is a central driver of many food security and health inequities related to CEC. Not only does CEC affect the availability of fresh and clean water (e.g. through droughts or floods leading to chemical waste runoff from industrial agriculture), it also exacerbates existing political tensions and power struggles around water security (e.g. due to irrigation schemes moving water away from poorer to richer farmers, or the activities of transnational corporations, or the fracking industry). In fact, unlike food systems which are extremely complex and impacted by several heterogeneous factors, water can be more clearly linked to power as the central issue affecting availability and access. Therefore, we hypothesize that water sovereignty can provide a means of achieving water sustainability and security, through the strengthening of local rights and control over the supply and use of water, while protecting biodiversity, and local economies. To explore this hypothesis, we are conducting a review to determine the state of knowledge with respect to water sovereignty and its demonstrated or perceived potential for promoting water security and sustainability; and thus improved health equity across local and global scales and for future generations. Despite the perceived benefits of water sovereignty, there is a lack of knowledge or guidance in terms of how to achieve this within political systems that are dominated by globalized corporatist or macro-development interests.

Assessing dietary diversity through HIES as a proxy measure for food security status

Authors: Quentin Hanich1, Anne Lechner1, Joanna Russell1
Author Affiliations: 1University of Wollongong

Background: Households that have regular access to a safe and nutritious diet are considered to be food secure. A number of proxy measures are available to measure food security using data collected from Household Income and Expenditure Surveys (HIES). These national level surveys have been implemented in a number of countries and territories within the Pacific Islands and to date, nine countries have conducted two or more HIES. The aim of this study is to assess dietary diversity through HIES as a proxy measure for food security status using two validated methods.

Methods: The Food Consumption Score (FCS) is a composite score at the household level based on dietary diversity, food frequency and the relative nutritional importance of the various food groups Whereas the Household Dietary Diversity Score (HDDS) is a score based on the sum of 12 food groups, of which each food group is given equal weighting. FCS and HDDS scores were calculated from expenditure data collected as part of the 2013-2014 Federated States of Micronesia HIES. 

Analysis is ongoing and interpretation of results along with the methodological strengths and limitations will be presented at the Planetary Health Alliance Inaugural Meeting on 29-30th April 2017.

Spatial, social and environmental determinants of malnutrition in Kenya

Authors: James Berkley1, Thomas Gachie, Damaris Kinyoki, John Muriuki, Rosie Crane, Grainne Moloney3, Abdidsalan Noor4
Author Affiliations: 1Professor of Paediatric Infectious Diseases, Centre for Tropical Medicine & Global Health, University of Oxford, UK & KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya; 2KEMRI/Wellcome Trust Research Programme; 3UNICEF; 4WHO

During the next 20 years, is is estimated that 527,000 children’s lives will be lost because of malnutrition. Malnutrition has a broad range of determinants that may vary from in space and time, which may need different approaches for interventions. We are applying geo-statistical methods to understanding the burden, spatial distribution and determinants of malnutrition amongst children aged less than five years in Kenya.

We are combining existing data from national surveys with remote sensing and other datasets on climate and environment (rainfall, temperature, altitude, vegetation and urbanization); land cover and land use (soil type, vegetation, agriculture and livestock density); and accessibility (to health antenatal care, water and sanitation and markets) and new data from our own targeted, small area, high-resolution censuses in four ecological zones within Kenya: selected to represent Kenya’s livelihood zones: pastoral (Kanukurudio, Turkana), coastal (Junju, Kilifi), arable (Nyando, Kisumu) and urban slum (Mathare, Nairobi). At each site, a spatially contiguous community is selected and all households within invited to participate. Stunting at sites ranged from 18 to 47%; wasting from 4 to 26%. We have assembled, geolocated and re-coded all of the national survey datasets since 2002 including DHS, MICs, malaria and AIDS indicator surveys as well as nutritional SMART surveys conducted by NGOs and UN agencies. We are applying Bayesian space-time modelling that has been pioneered for infectious diseases such as malaria to malnutrition.

We are creating: i) an understanding of the heterogeneity of prevalence and determinants of malnutrition, reflecting diverse ecologies and determinants; ii) maps that clearly characterize the current burden and distribution of the determinants of malnutrition; iii) predictions of future trends (e.g. with increasing urbanization, climate change or interventions); and iv) tools to directly guide strategies to improve nutrition and health at a sub-national level.

A fully integrated macroeconomic, environmental, demographic and health analysis of palm oil policies in Thailand

Authors: Marcus, Keogh-Brown, Henning Tarp Jensen, Sanjay Basu, Alan Dangour, Shabbir Gheewala, Rosemary Green, Edward Joy, Nalitra Thaipresert, Soledad Cuevas, Bhavani Shankar, Richard Smith

Agriculture and food systems are inextricably linked to health, the economy, and the environment, and palm oil is one of the most prominent commodities for all of these policy areas. Economic benefits from palm oil include high yields, low production costs and advantageous qualities for food processing. However, as a leading source of dietary saturated fat, it has been linked with negative health outcomes and, sometimes, with negative environmental effects. To capture this mutual dependency and complex interactions we developed a novel integrated approach.

Our MED-health model integrates Macroeconomic, Environmental, Demographic, and health models and modules in one framework. It focuses on regional nutrient intakes from food demand (including palm oil), their implications for population serum cholesterol levels and clinical health outcomes, and on land use change for oil palm production and their implications for carbon sequestration. Clinical health outcomes (myocardial Infarction and stroke) are linked to labor market participation and to public/private hospital and care expenditures, allowing a holistic analysis of proposed government policies. We apply this methodology to Thailand, a significant producer and consumer of palm oil.

Analysis shows that policies to reduce Thai palm oil consumption by 50% yield positive health and economic impacts saving more than 3000 lives and raising national income by 0.32%/1.8bn USD annually by 2035. Health benefits fall primarily on rural households while economic costs of reduced production primarily affect poorer Southern households. A key and unique feature of Thailand’s oil palm production has been that it is predominantly based on Southern smallholder production in abandoned paddy fields and waste lands. Thus the reduction in oil palm plantations, counterintuitively, reduces carbon sequestration and increases annual CO2-equivalent emissions by more than 0.5Mt by 2035. The results underscore the importance of retaining the smallholder, low-impact nature of Thai oil palm production, while mitigating health impacts.

Planetary Health, Space, and Place as Frameworks for Sustainable and Equitable Food and Nutrition Systems in the Developing World

Authors: David Lopez-Carr1, Britta Schumacher1, Emily Williams1, Sylvia Cifuentes1, Kevin Mwenda1, Daniel Ervin1, Brian Kastl1, Woutrina Smith2, Sam Ying3, 4Nancy Suski, 5Federico Castillo
Author Affiliations: 1UC Santa Barbara; 2UC Davis; 3UC-Riverside; 4Lawrence Livermore Lab; 5UC-Berkeley

By 2050, the world’s agricultural system must simultaneously provide food for a projected 9.6 billion people. The challenge, of creating just, equitable and regenerative agricultural systems to feed the planet while limiting environmental degradation, reducing greenhouse gas emissions and creating economic opportunities for the rural poor, emerges at a critical time—as climate change and variability threaten the ability of built and natural systems to provide services humanity depends on to survive. Planetary health and the state and stewardship of our natural systems directly impact human health outcomes. In the case of subsistence and smallholder agriculturalists, the integrity of the environment (ie. the health of soils, predictability of local climatology, presence of pollinators) remains integral to the provisioning of an ample and nutritionally diverse food supply. Climate impacts on these food systems, and therefore, food and nutritional security, will vary spatially and temporally with disproportionate impacts on the most vulnerable populations. Though the academic literature provides ample evidence for the geography of climate change and food security, the evidence base surrounding the spatial and temporal interactions between climate and nutrition is much smaller. This gap in the literature presents a challenge and opportunity. Guided by a planetary health framework, we assess how food and nutritional security among the most vulnerable populations to food insecurity – rural inhabitants in the developing world- is driven by various socioeconomic, biophysical, and political factors that may be exacerbated by climate change at varying scales. An attention to spatial and temporal scales and place-based variation helps identify knowledge gaps related to nutrition and food security.

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