Plant-based diets linked to lower mortality risk and environmental impact

A large-scale study suggests diets rich in fruits, vegetables, whole grains, and plant-based proteins are associated with a significant reduction in mortality risk and a smaller environmental footprint.

This research, published in The American Journal of Clinical Nutrition, is the most extensive to date examining the combined health and environmental benefits of the EAT-Lancet Planetary Health Diet. Launched in 2019, this diet promotes a focus on plant-based foods while allowing moderate amounts of animal products like meat and dairy.

Researchers led by Dr Walter Willett, Professor of Epidemiology & Nutrition at Harvard School of Public Health, analyzed dietary information from over 200,000 American nurses over a 34-year period. They evaluated participants' diets based on 15 key food groups, aligning them with the Planetary Health Diet recommendations. Additionally, they tracked participants' health outcomes, including cancer, diabetes, and heart disease.

The study revealed a clear link between plant-rich diets and improved health. Individuals whose diets most closely resembled the Planetary Health Diet had a 23% lower risk of premature death compared to those with the least plant-based intake. This translated to specific reductions in mortality risk from various diseases: 14% lower for cardiovascular disease, 10% lower for cancer, 28% lower for neurodegenerative conditions, and a striking 47% lower for respiratory disease.

The environmental benefits were equally impressive. Plant-based diets resulted in a 29% decrease in greenhouse gas emissions, 21% less fertilizer use, and a 51% reduction in required cropland. This significant land-use decrease could have further climate advantages if converted back to natural habitat, promoting carbon sequestration.

While the study establishes a correlation, not causation, between plant-based diets and health, it supports the existing research on the connection between greener diets and positive health outcomes. Notably, the researchers considered factors like exercise and smoking habits.

This groundbreaking research strengthens the case for plant-forward eating as a powerful tool to combat both chronic illness and environmental degradation. Importantly, Dr Willett emphasized that adopting a more plant-based diet doesn't necessitate drastic changes. "The Planetary Health Diet allows for moderate amounts of meat and dairy, offering a significant double win for human and planetary health," he concluded.