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Closely following a planet-friendly diet consisting mostly of fruits, vegetables and whole grains reduces the risk of premature death in humans by almost a third, while also significantly reducing the emissions of planet-destroying greenhouse gases, according to a new study.
Preventive and lifestyle medicine specialist Dr. “Eating more plant foods, less animal foods and less processed foods is better for both people and the planet,” said David Katz.
“We see the same message amplified in this article: Adhering to a diet that is conducive to the health of the planet and sustainability is associated with meaningful reductions in all-cause mortality,” he said in an email. Katz is the founder of the nonprofit Real Health Initiative, a global coalition of experts dedicated to evidence-based lifestyle medicine.
Food production plays an important role in the climate crisis. Raising animals for human consumption, for example, uses vast amounts of agricultural land and contributes to deforestation, biodiversity loss and water pollution, experts say.
Ruminant animals can emit harmful gases that have a surprising impact on the environment. According to the UN Environment Programme, burps and poop from cattle, sheep and goats produce methane, a greenhouse gas 80 times more powerful than carbon dioxide, warming the planet within 20 years.
For example, an adult cow can belch or fart up to 500 liters of methane per day. Experts say that when we add them up, they could account for about 15% of total global greenhouse gas emissions.
However, according to research, eating a planet-healthy diet reduces land use by 51%, greenhouse gas emissions by 29% and fertilizer use by 21%, while also extending people’s lives.
“Changing the way we eat could help slow climate change, and fortunately, what’s healthiest for the planet is also best for us,” the corresponding author said. Walter WillettProfessor of epidemiology and nutrition at Harvard T.H. Chan School of Public Health in Boston.
“For every major cause of death we looked at, there was a lower risk in people who were better adherent to the planetary health diet,” Willett said.
A diet for people and planet
In 2019, the EAT-Lancet Commission, comprised of 37 leading scientists from 16 countries, created a diet with the dual goals of maximizing human health while reducing the environmental impact of feeding billions of people.
The resulting meal plan emphasized eating more of a variety of fruits and vegetables, whole grains, legumes, and other plant-based proteins, while reducing meat and dairy to small portions.
The study, published Monday in The American Journal of Clinical Nutrition, analyzed nutritional data collected from more than 200,000 men and women to see how they matched the Eat-Lancet nutritional guidelines.
All subjects were enrolled in long-term government studies (Nurses’ Health Study I and II and the Health Professionals Follow-up Study) and did not have any significant illnesses when the study began. Every four years for 34 years, study participants filled out dietary surveys, providing researchers with a tremendous amount of data.
The researchers then scored the diets based on intake of 15 food groups. Foods that are good for the planet require fewer overall resources to grow and include whole grains, tubers, vegetables, whole fruits, legumes, soybean foods, and unsaturated vegetable oils such as olive oil.
Foods that require large amounts of land use, such as cattle and, to a lesser extent, sheep, goats, pigs and poultry, were also measured, as was consumption of added sugars, which carry many known health risks.
Willett said other studies have examined the impact of the planetary health diet, but none match the scope of this study. “This is a much larger and much longer study in which dietary assessments were repeated over three decades, allowing for greater statistical precision,” he said.
The study found that the top 10% of people following the Eat-Lancet planetary diet were 30% less likely to die prematurely from any cause than those in the bottom 10%.
In addition, those who most closely followed the planetary diet had a 28% lower risk of neurodegenerative death, a 14% lower risk of dying from cardiovascular disease, a 10% lower risk of dying from cancer, and a 47% lower risk of dying from a heart attack. Willett said it is a respiratory disease that is also seen in non-smokers.
“The findings show how human and planetary health are linked. Eating healthy increases environmental sustainability, which is essential for the health and well-being of every person on Earth,” he added.
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