Planetary Health Diet could help prevent millions of early deaths
Increasing global adoption of the Planetary Health Diet (PHD) could lead to millions fewer premature deaths each year, according to a new study led by researchers at Harvard T.H. Chan School of Public Health.
The study was published Dec. 2 in Proceedings of the National Academy of Sciences. Walter Willett, professor of epidemiology and nutrition, was corresponding author.
The PHD emphasizes high intake of vegetables, fruits, whole grains, legumes, nuts, and unsaturated oils; modest intake of seafood and poultry; and limited intake of red meat, processed meat, added sugar, salt, refined grains, and starchy vegetables. It also encourages foods that are minimally processed or unprocessed. Previous studies have shown that global adherence to the PHD is low. According to the researchers, the new study refines prior research by using better data and improved analytic approaches.
The researchers used national dietary data from the Food and Agriculture Organization of the United Nations to evaluate how closely current diets around the world align with PHD recommendations. They assessed diets according to the Planetary Health Diet Index (PHDI), which ranges from a score of 0 (non-adherence to the PHD) to 140 (perfect adherence).
The study found that PHDI scores varied substantially across countries, but that adherence was universally far from optimal, with a mean score of 85. The researchers estimated that by improving the global PHDI score to 120, each year approximately 15 million deaths—27% of total deaths among adults—could be averted. This would include 2.5 million deaths from cardiovascular diseases and 0.7 million deaths from neurodegenerative diseases.
The researchers found that countries around the Mediterranean Sea generally had better adherence to the PHD, providing evidence that the diet is practical and achievable. Low adherence was observed in both high- and low-income countries. In high-income countries, the authors noted, low adherence stems from agricultural policies that result in low costs for red meat and high costs for fruits and vegetables; in low-income countries, people simply don’t have enough money to buy a lot of nutrient-dense foods.
Read the study: Global adherence to a healthy and sustainable diet and potential reduction in premature death