The health of the planet and human health are deeply interconnected. Under this planetary health approach, a pioneering study conducted in Spain has managed to quantify the environmental impact derived from our diet on public health.
The results are compelling: the consumption of meat, fish, seafood, and dairy products accounts for 55% of the total impact on human health.
Advanced methodology to measure environmental damage with health consequences
The research, published in Environmental Research and led by the Barcelona Institute for Global Health (ISGlobal), used Life Cycle Assessment (LCA) to assess the environmental impact of the food system —from production to consumption— and its relationship with human health. The data was based on the 2022 dietary surveys from the Spanish Ministry of Agriculture, Fisheries and Food.
Indicators analyzed included:
- Climate change
- Formation of suspended particles
- Human toxicity
- Ionizing radiation
- Formation of photochemical oxidants
- Ozone layer depletion
Health consequences included cardiovascular, respiratory diseases, malnutrition, cancers, and diarrheal diseases, among others.
The impact of food on human and planetary health
An alarming figure: 447,152 years of life lost or lived with disability
In 2022 alone, the Spanish food system generated a loss of 447,152 Disability-Adjusted Life Years (DALYs), a metric combining premature deaths and years lived with disabilities.
Of the total, 95% of the impact was attributable to food consumption, and the remaining 5% to food waste.
Animal-based foods: main culprits of environmental damage with health consequences
Among the 16 food groups analyzed, animal-based products were the most harmful, accounting for 55% of the environmental damage with health implications.
Additionally, they showed a significantly higher health burden than plant-based foods.
Climate change was the primary environmental factor associated with the damage, responsible for 77% of the total impact, followed by formation of suspended particles (16%) and human toxicity (7%).
Improvement scenarios: plant-based diet and waste reduction
The study evaluated hypothetical scenarios to reduce environmental impact and improve health:
- Replace red and processed meat with white meat: modest benefits
- Substitute meats and dairy with plant-based foods: up to 30% reduction in health impact
- Eliminate food waste: additional 5% improvement
Together, these changes could reduce health damage derived from the food system by 35%.
Healthier nutritional profile with a plant-based diet
The team also analyzed the nutritional implications of the diet change, evaluating key nutrients such as proteins, calcium, iron, fiber, and vitamin B12.
Although the intake of proteins, calcium, and B12 would decrease, it would remain within the ranges recommended by the World Health Organization (WHO). In contrast, fiber and iron would increase significantly, improving the overall nutritional profile.
A scientific basis for sustainable food policies
This work not only demonstrates the direct relationship between diet, environment, and health, but also provides a solid foundation for the design of public policies promoting more sustainable and healthier diets.
The research was supported by the “la Caixa” Foundation and received assistance from the Daniel and Nina Carasso Foundation.
