A landmark study from the Harvard T.H. Chan School of Public Health found that following a healthy and sustainable diet can considerably lower the risk of early death while minimizing environmental impact. This is a preliminary large-scale research to directly assess the effects of following the recommendations of the major 2019 EAT-Lancet report. The report’s dietary pattern, known as the Planetary Health Diet (PHD), stresses a range of primarily raw plant foods with limited consumption of dairy and meat products.

Climate-Food Connection:

Walter Willett, professor of epidemiology and nutrition and the co-author of the study, emphasizes the importance of our food system in climate change. “Climate change has the world on track for environmental catastrophe, and our food chain plays a major part,” Willett said. He underlined that changing food habits can help decrease the rate of global warming and thus what is best for the world is also good for humanity.

Prior Studies and Research Methodology:

While prior research has suggested that diets centered on plant-based foods rather than animal-based meals may promote both human and environmental health, these studies mainly relied on a single dietary assessment. Such approaches are less reliable than long-term dietary evaluations.

Researchers used health data from nearly 200,000 participants in the Nurses’ Health Studies I and II, as well as the Health Professionals Monitoring Study, to conduct this study. Participants, who clear of significant chronic conditions at the time, filled out dietary surveys every twelve months for up to 34 years. To assess adherence to the PHD, meals rated based on the consumption of 15 food groups, comprising whole grains, veggies, poultry, and nuts.

Key Outcomes:

The outcomes of the research are substantial. Those in the top ten percent of PHD adherence had a 30% decreased risk of early death than those in the bottom ten percent. Moreover, This decrease was reported for all main causes of mortality, including cancer, cardiovascular disease, and lung cancer.

Environmental Impact:

In addition to health advantages, the study discovered significant environmental benefits for individuals who rigorously adhere to the PHD. High compliance with the PHD linked to 29% reduced carbon dioxide emissions, 21% fewer fertilizer requirements, and 51% less cropland usage. These reductions are critical for fostering forest restoration, which is regarded as an effective technique for decreasing greenhouse gases that cause climate change.

Policy Implications:

Willett criticized the US Department of Agriculture’s refusal to address the environmental consequences of food choices in the planned revision of the US Food Guidelines. “Our study is significant given that the U.S. Department of Agriculture has declined to consider the ecological consequences of food choices and any reference to the environmental impacts of diet will not be permitted in the coming update of the U.S. Dietary Guidelines,” he said. The study emphasizes the inextricable link between human well-being and environmental sustainability, proposing dietary standards that take into account both.

Contributions and Funding:

Linh Bui, Fenglei Wang, Qi Sun, Frank Hu, Kyu Ha Lee, and Marta Guasch-Ferre, all of whom work at Harvard Chan School, are co-authors of the study. The study was supported by NIH research grants UM1 CA186107, P01 CA87969, R01 HL034594, U01 CA176726, U01 CA167552, R01 HL035464, R01 DK120870, and R01 DK126698.

Comprehensive Review of Planetary Health Diet:

The Planetary Health Diet, as proposed by the EAT-Lancet study, is a comprehensive dietary plan aimed at improving both human health and the sustainability of the environment. It contains a wide variety of minimally processed plant-based foods, including fruits, vegetables, whole grains, legumes, nuts, and seeds. The diet also provides for moderate consumption of animal-derived items, such as meat and dairy, albeit in substantially smaller quantities than traditional Western diets.

Elements of Planetary Health Diet:

Fruits and vegetables:

These are the foundation of the PHD, with suggestions for at least 5 servings each day. They include vital minerals, vitamins, fiber, and radicals that are necessary for good health and the prevention of chronic diseases.

Whole Grains:

Brown rice, quinoa, oats, and whole-grain wheat are preferable to refined grains. They are high in nutritional fiber, which improves digestion, and have a low glycemic index, which helps manage blood sugar levels.

Legumes:

Beans, lentils, chickpeas, and many other legumes are rich in plant-based protein and fiber. They are also moderate in fat and can help improve heart health by decreasing cholesterol levels.

Nuts and Seeds:

Nuts and seeds contain healthful fats, protein, and important vitamins. Regular intake of nuts and seeds has been related to a lower risk of cardiovascular disease.

Dairy and Meat:

The PHD encourages moderate intake of dairy and meat, with a focus on fewer servings and higher-quality, environmentally friendly options. This move helps to lessen the environmental impact of animal husbandry.

Fish and Poultry:

Fish and poultry favored to red and processed meat. A Fish, especially fatty fish such as salmon, contain omega-3 fatty acids, which are helpful to heart health.

Plant Oils:

Healthy plant oils like olive oil and canola oil advised for cooking and dressing, as they replace saturated and trans fats found in processed meals.

Final Thoughts:

The Planetary Health Diet, which stresses minimally processed plant foods while allowing for moderate consumption of meat and dairy, has been linked to a substantial decrease in the risk of premature death and less environmental harm. Both findings emphasize the potential for dietary adjustments to promote human health and environmental sustainability, prompting a reevaluation of dietary standards to incorporate both advantages. The complete study, “Planetary Health Diet Index and Risk of total and cause-specific mortality in Three Prospective Cohorts,” will be published in The American Journal of Clinical Nutrition on June 10, 2024.

At last, the PHD’s twin advantages to wellness and the environment highlight the importance of integrating public health with sustainable strategies. Individuals, organizations, and policymakers may all help to create a healthier, more environmentally friendly future by embracing and promoting the PHD.