The Role of the Planetary Health Diet in Combating Chronic Diseases, Climate Change

The Planetary Health Diet (PHD) may help individuals reduce the risk of premature death and lower their environmental impact, according to researchers from the Harvard T.H. Chan School of Public Health. Climate change has a significant impact on the stability of food systems, leading to poorer diet quality and increased risk of adverse health events, such as heart disease, cancer, and lung disease. By adopting a dietary pattern with high consumption of fruits, vegetables, whole grains, legumes, nuts, and seeds, and moderate intake of animal-based products and ultra-processed foods, individuals can reduce the burden of chronic disease while promoting planetary health.¹

By adopting a dietary pattern with high consumption of fruits, vegetables, whole grains, legumes, nuts, and seeds, and moderate intake of animal-based products and ultra-processed foods, individuals can reduce the burden of chronic disease while promoting planetary health. Image Credit: © peangdao - stock.adobe.com

Proper nutrition is a key determining factor for preventing and managing chronic health conditions, and growing consumption of ultra-processed foods has poor implications for individual health. Ultra-processed foods are made from high-yielding plant species, such as corn, wheat, soy, and oil seed crops, which require significant land and water usage. Additionally, predominance of farming these crops limits cultivation of other plants, severely impairing biodiversity and nutritional quality of food.¹

Ultra-processed foods are associated with numerous health effects, including increased cancer risk, obesity, cardiovascular disease (CVD), high blood pressure, and diabetes.² The PHD follows a flexible framework that is abundant in fruits, vegetables, nuts, legumes, and grains, with modest consumption of ultra processed foods to promote health and environmental sustainability. A typical plate consists of 50% fruits and vegetables, 25% whole grains, and 25% plant- and animal-based protein sources, providing essential nutrients, including vitamins, minerals, fiber, and antioxidants, which are crucial for preventing and combating chronic diseases.³

The researchers assessed health data from more than 150,000 women from the Nurses’ Health Study and Nurses’ Health Study 2, as well as 47,274 men from the Health Professionals Follow-up Study. The participants were free of cancer, diabetes, and major CVDs at baseline and completed dietary questionnaires every 4 years for up to 34 years. The researchers determined adherence to PHD based on intake scores of the 15 food groups, including whole grains, vegetables, poultry, and nuts.^4,5

The results demonstrated that greater adherence to PHD was associated with lower risk of deaths from CVDs(HR: 0.86; 95% CI: 0.81, 0.91), cancer (HR: 0.90; 95% CI: 0.85, 0.95), respiratory diseases (HR: 0.53; 95% CI: 0.48, 0.59), and neurodegenerative diseases (HR: 0.72; 95% CI: 0.67, 0.78). The researchers also observed a 30% lower overall risk of premature death in the top 10% of participants who most closely adhered to the diet.⁴

Additionally, individuals with higher adherence to the PHD had significantly lower environmental impact, including 29% lower greenhouse gas emissions, 21% lower fertilizer needs, and 51% lower cropland use.⁵

These findings highlight the dual benefits of the PHD, demonstrating its potential to reduce the risk of premature death from chronic diseases while also lessening the environmental impact of food production. As the global population continues to grow and climate change further stresses agricultural resources, adopting dietary patterns like the PHD becomes increasingly critical for ensuring long-term health and environmental stability. The evidence supports a shift towards diets that balance human nutritional needs with the planet's ecological limits, paving the way for a healthier future for both people and the planet.

References

1. Leite FHM, Khandpur N, Andrade GC, et al. Ultra-processed foods should be central to global food systems dialogue and action on biodiversity. BMJ Glob Health. March 2, 2022. doi:10.1136/bmjgh-2021-008269
2. The many health risks of processed foods. Laborers’ Health and Safety Fund of North America. Accessed June 18, 2024. https://lhsfna.org/the-many-health-risks-of-processed-foods/#:~:text=Heavily%20processed%20foods%20often%20include,Lacking%20in%20nutritional%20value
3. Planetary health diet linked to lower risk of death from cancer, heart disease. Medical News Today. June 10, 2024. Accessed June 18, 2024. https://www.medicalnewstoday.com/articles/planetary-health-diet-linked-to-lower-risk-of-death-from-cancer-heart-disease
4. Bui L, Pham T, Wang F, et al. Planetary Health Diet Index and risk of total and cause-specific mortality in three prospective cohorts. American Journal of Clinical Nutrition. June 10, 2024. doi:10.1016/j.ajcnut.2024.03.019
5. Planetary health diet associated with lower risk of premature death, lower environmental impact. EurekAlert! June 10, 2024. Accessed June 18, 2024. https://www.eurekalert.org/news-releases/1046921