June 10, 2024 – Eating a diet filled with fruits, vegetables, and whole grains might not just lead to a longer life, but may also help reduce greenhouse gas emissions and give a boost to other things that sustain the environment, a new study has found.
For the study, researchers analyzed data from the diets of 200,000 people, gauging how well their choices aligned with the planetary health diet. A panel of experts proposed the eating plan in 2018 for people to maximize personal health and planetary health.
People who most closely followed the diet had a 25% reduced risk of early death, and were less likely to die of heart problems, cancer, respiratory diseases, or neurodegenerative diseases like Alzheimer’s or Parkinson’s, compared to people who mostly ate animal protein, foods with added sugars, and processed foods.
Women who closely followed the diet were less likely to die of infectious diseases, but the same pattern did not apply to men. The researchers called the link they observed between the diet and reduced risk of respiratory diseases, like chronic obstructive pulmonary disease (COPD), as being among the “most striking” health impacts.
The findings were published Monday in The American Journal of Clinical Nutrition. The people in the study provided detailed information about their diets every 4 years for up to 34 years, and all of them were either nurses or other health care professionals.
The planetary health diet proposes about 2,500 calories per day, with half of a person’s daily nutrition coming from fruits and vegetables, followed mainly by whole grains and plant-based protein. The diet may include small amounts of dairy and animal-sourced protein, and oils should be unsaturated plant oils. The creators of the diet described it as optimizing human health and environmental sustainability.
“Climate change has our planet on track for ecological disaster, and our food system plays a major role,” study author Walter Willett, MD, a professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health, said in a statement. “Shifting how we eat can help slow the process of climate change. And what’s healthiest for the planet is also healthiest for humans.”
The researchers estimated that closely following the planetary health diet could have a broad environmental impact, including 29% lower greenhouse gas emissions, 21% lower fertilizer needs, and 51% less cropland use, compared to following a diet mostly made up of highly processed or animal-based foods.
“The findings show just how linked human and planetary health are,” Willett said. “Eating healthfully boosts environmental sustainability — which in turn is essential for the health and wellbeing of every person on earth.”
