News Release

These foods can help you live longer and protect the planet

New diet score reveals foods that are a win-win for your health and the environment

Reports and Proceedings

American Society for Nutrition

Association between mortality and PHDI

image: A plot of the relationship between risk of death from various causes and adherence to the Planetary Health Diet Index (PHDI). People in the highest quintile for PHDI (Q5) showed a significantly lower risk of death from all causes compared with those in the lowest quintile. view more 

Credit: Linh Bui et al. at NUTRITION 2023

Eating more planet-friendly foods could help you live a longer, healthier life, according to new research. Researchers found that people who followed a more environmentally sustainable diet were 25% less likely to die during a follow-up period of over 30 years compared to those with a less sustainable diet.


The study builds upon prior research that identified foods that are a win-win for both health and the environment—such as whole grains, fruit, non-starchy vegetables, nuts, and unsaturated oils—as well as foods that could be harmful to the environment and human health, like eggs and red and processed meats. The new findings suggest eating more planet-friendly foods can help reduce a person’s risk of death from causes such as cancer, heart disease, respiratory diseases, and neurodegenerative diseases.


“We proposed a new diet score that incorporates the best current scientific evidence of food effects on both health and the environment,” said Linh Bui, MD, a PhD candidate in the Department of Nutrition at Harvard T.H. Chan School of Public Health. “The results confirmed our hypothesis that a higher Planetary Health Diet score was associated with a lower risk of mortality.”


Bui will present the findings at NUTRITION 2023, the flagship annual meeting of the American Society for Nutrition held July 22–25 in Boston.


According to existing evidence, plant-based foods are associated with both a lower risk of chronic diseases such as heart disease, colorectal cancer, diabetes, and stroke, and reduced impacts to the environment in terms of factors like water use, land use, nutrient pollution, and greenhouse gas emissions.


With the new study, the researchers aimed to create a simple tool that policymakers and public health practitioners could use to develop strategies to improve public health and address the climate crisis.


“As a millennial, I have always been concerned about mitigating human impacts on the environment,” said Bui. “A sustainable dietary pattern should not only be healthy but also consistent within planetary boundaries for greenhouse gas emissions and other environmental parameters.”


To create their Planetary Health Diet Index (PHDI), researchers reviewed existing research on the relationships between various food groups and health outcomes based on the EAT-Lancet reference diet that accounts for the environmental impacts of food production practices. They then applied the index to analyze outcomes among over 100,000 participants in two large cohort studies conducted in the United States. The data set included over 47,000 deaths during a follow-up period spanning over three decades from 1986-2018.


Overall, they found that people in the highest quintile (the top one-fifth of participants) for PHDI had a 25% lower risk of death from any cause compared to those in the lowest quintile. Higher PHDI scores were associated with a 15% lower risk of death from cancer or cardiovascular diseases, a 20% lower risk of death from neurodegenerative disease, and a 50% lower risk of death from respiratory diseases.


Bui cautioned that the PHDI does not necessarily reflect all food items and their relationships with all major diseases in all countries. People with specific health conditions, religious restrictions, or different food accessibility due to socioeconomic status or food availability may face challenges with adhering to a more sustainable diet pattern. Further research could help to elucidate and address such barriers.


“We hope that researchers can adapt this index to specific food cultures and validate how it is associated with chronic diseases and environmental impacts such as carbon footprint, water footprint, and land use in other populations,” said Bui.


Bui will present this research at 11:45 a.m. EDT on Sunday, July 23, during the Dietary Patterns Poster Session in the Hynes Convention Center Hall C (abstract; presentation details).


NUTRITION 2023 will feature several studies using the Planetary Health Diet Index for which Bui is a co-author. Andrea Romanos-Nanclares, PhD, will present “Planetary Health Diet Index and Risk of Total and Subtypes of Breast Cancer in the Nurses’ Health Studies” at 11:45 a.m. EDT on Sunday, July 23, during the Nutritional Epidemiology (I) Poster Session (abstract; presentation details). Caleigh Sawicki, PhD, will present “Planetary Health Diet and Risk of Incident Cardiovascular Disease: Findings From Two Cohorts of US Women” at 2 p.m. EDT on Monday, July 24, during the Dietary Patterns and Health Outcomes Oral Session (abstract; presentation details).


Please note that abstracts presented at NUTRITION 2023 were evaluated and selected by a committee of experts but have not generally undergone the same peer review process required for publication in a scientific journal. As such, the findings presented should be considered preliminary until a peer-reviewed publication is available.


About NUTRITION 2023

NUTRITION 2023 is the flagship meeting of the American Society for Nutrition and the premier educational event for nutritional professionals around the globe. NUTRITION brings together lab scientists, practicing clinicians, population health researchers, and community intervention investigators to identify solutions to today’s greatest nutrition challenges. Our audience also includes rising leaders in the field – undergraduate, graduate, and medical students. NUTRITION 2023 will be held July 22-25, 2023 in Boston. #Nutrition2023


About the American Society for Nutrition (ASN)

ASN is the preeminent professional organization for nutrition research scientists and clinicians around the world. Founded in 1928, the society brings together the top nutrition researchers, medical practitioners, policy makers and industry leaders to advance our knowledge and application of nutrition. ASN publishes four peer-reviewed journals and provides education and professional development opportunities to advance nutrition research, practice, and education. Since 2018, the American Society of Nutrition has presented NUTRITION, the leading global annual meeting for nutrition professionals.


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