A study links the environmental impact of our food choices to damage to human health
- Meat, fish and dairy products: the foods that are most harmful to human health through their environmental impact
- Dietary changes that can improve global health
- Implications for public health
- Reference
The health of the planet and the health of people are closely linked. What harms the environment, in the short or long term, also has an effect on human health. With this planetary health approach, a pioneering study in Spain has quantified for the first time the damage that the environmental impacts of our food demand ultimately have on health.
The results reveal that the consumption of meat, fish, seafood and dairy products accounts for 55% of the damage to human health. According to the study, changing consumption patterns and reducing food waste could prevent up to 35% of this impact. The research, published in Environmental Research, was led by the Barcelona Institute for Global Health (ISGlobal), a centre promoted by the ‘la Caixa’ Foundation, and was supported by the Daniel and Nina Carasso Foundation.
The research team applied a state-of-the-art scientific methodology, Life Cycle Assessment (LCA), to quantify the various environmental impacts of the food system (from production to consumption) and how they affect human health. The data were based on the 2022 food surveys published by the Spanish Ministry of Agriculture, Fisheries and Food.
The research team used statistical models to assess the environmental effects on human health, evaluating various key indicators such as climate change, ozone depletion, toxicity to humans, particulate matter formation, ionising radiation and the formation of photochemical oxidants. The health consequences analysed included cardiovascular disease, malnutrition, diarrhoea, various types of cancer and respiratory diseases, among other conditions.
The results indicate that, in 2022 alone, the environmental impact of food demand in Spain was associated with a loss of 447,152 disability-adjusted life years (DALYs). This is a widely used measure in the field of public health that combines both years lost due to premature death and years lived with illness or disability. Of the total environmental impact of food demand with health consequences, 95% was attributable to food consumption and the remaining 5% to food waste.
Meat, fish and dairy products: the foods that are most harmful to human health through their environmental impact
Among the 16 food groups analysed, meat, fish and seafood, and dairy products were identified as the main contributors to environmental damage with health consequences, accounting for 55% of the total impact of consumption. In addition, these animal-based foods showed a significantly higher health burden than plant-based products.
Among the negative effects of the food system, the contribution to climate change was the main environmental factor associated with health damage, accounting for 77% of the total impact. This was followed by the formation of particulate matter (16%) and human toxicity (7%). Other impacts such as the formation of photochemical oxidants, ozone depletion and ionising radiation contributed to a lesser extent.
Dietary changes that can improve global health
The study evaluated various hypothetical scenarios based on measures commonly promoted to reduce the environmental impact of food, with the aim of quantifying the potential benefits for human health. In the first scenario, replacing red and processed meat with white meat showed small benefits.
However, the greatest benefit came from replacing all meat and dairy products with plant-based foods. This change could reduce the damage to human health from environmental factors by up to 30%. In addition, eliminating food waste by consumers could achieve an additional 5% reduction in impact, for a total improvement of 35%.
The research also set out to assess the nutritional implications of replacing meat and dairy with plant-based foods. Specifically, the team examined total energy intake and key macronutrients and micronutrients, including protein, saturated fat, fibre, calcium, sodium, iron, zinc and vitamin B12.
With the change in diet, a nutritional profile more in line with that recommended by the World Health Organisation (WHO) was observed. Protein, calcium and vitamin B12 intake would decrease, but levels would remain within the ranges recommended by the WHO. In contrast, fibre and iron intake would increase significantly, which is particularly relevant given the current deficit of these nutrients in the Spanish diet.
Implications for public health
This study not only highlights the close relationship between diet, the environment and health, but also opens up new opportunities to improve public health through a more sustainable and responsible diet. ‘The proposed changes would not only reduce environmental impact, but also bring the average diet in Spain closer to the WHO's nutritional recommendations, thus moving towards a healthier diet in a comprehensive sense,’ says Ujué Fresán, ISGlobal researcher and first author of the study.
In addition, the research provides a solid scientific basis to guide the development of future food policies. ‘Our findings can serve as a starting point for designing and implementing policies that promote the transition towards healthier eating habits in Spain, considering both the direct and indirect benefits for human health,’ says Fresán.
Reference
Fresán, U., Núñez, M., Valls, I., Rosenbaum, RK. Quantifying the Environmental Human Health Burden of Food Demand in Spain: A Life Cycle Assessment Study. Environmental Research, 2025. Doi: 10.1016/j.envres.2025.122147
