How Much Do You Know About the Planetary Health Diet?

In 2019, the Lancet formed the EAT-Lancet Commission featuring leading scientists from 16 countries to analyze the environmental and health impact of the planetary health diet. The Commission’s report clearly outlines how eating healthy is not only good for a person’s health, but also for the environment as well.

New research from Harvard evaluated the diet’s impact on premature death and the environment. They analyzed data from three prospective cohorts featuring more than 200,000 adults that were followed for 34 years and published their findings recently in the journal Nutrition. They found that the risk of premature death from every major cause of death including cancer and heart disease was 30 percent lower in the participants who most closely followed the diet. In addition, higher adherence to the diet resulted in a substantially lower environmental impact with 51 percent lower cropland used, 29 percent lower greenhouse gas emissions, and 21 percent lower fertilizer needs.

This new study builds on past research that analyzed data from the Nurses’ Health Study, Nurses’ Health Study II, and Health Professionals Follow-up Study. It found that a higher Planetary Health Diet Index score, which represents dietary adherence, was associated with a lower risk of total and cause-specific mortality.

What is the planetary health diet?

The foundation of this diet is high-quality plant-based foods such as vegetables, fruits, nuts, legumes, whole grains, and unsaturated plant oils. The diet also features low to moderate amounts of animal-sourced foods and low amounts of saturated fats, sugar, and refined grains. From a visual standpoint, the Lancet describes it as half the plate filled with fruits, vegetables, and nuts and the other half consisting of whole grains, plant proteins, and modest amounts of meat and dairy.

Vegan and vegetarian diets are considered healthy versions of the planetary health diet. The planetary health diet is different from the Mediterranean diet because it allows meat and dairy, whereas with the Mediterranean diet, dairy and meat are more limited. The Mediterranean diet also places more emphasis on healthy fats such as olive oil and fish compared to the planetary health diet.

This latest study and the work of the EAT-Lancet Commission illustrate the clear link between human health and the health of the environment. Encouraging patients to eat more sustainably, will not only benefit the environment, but they will also likely live longer while reducing their risk of chronic illness.