A recent study found that while an overall plant-based diet is better for the environment than a diet that includes animal foods, a healthful plant-based diet centered around minimally processed plant foods has a strong health and environmental impact.
People may choose to go plant-based for a variety of reasons: health benefits, compassion for animals, and dedication to the environment. And a recent research study indicates that following a plant-based diet is, indeed, good for all three factors, however the type of plant-based diet (namely based on processed or whole foods) can make an even bigger difference for human and planetary health. There are multiple ways to help protect the environment through eating a plant based diet based on whole foods. That’s because whole plant based foods have a lower environmental impact.
In a study published by the Lancet Planet Health journal, researchers broke down the environmental impacts of the diets of over 60,000 participants in the Nurses’ Health Study II. The participants were all female nurses in the US, ages 25 to 42. The researchers excluded participants who already had cancer and heart disease at the beginning of the study. This was a prospective cohort study, where researchers collected a survey called a food frequency questionnaire to thoroughly assess the diets and health outcomes of over 60,000 nurses every 4 years from 1991 to 2017. They assessed the greenhouse gas emissions, fertilizer outputs, as well as land and water use of the 156 foods included in the food frequency questionnaire. In order to complete their environmental assessment, the researchers relied on previously published values from online databases.
The researchers found that animal-based foods, especially red and processed meat, had the most negative effects on the environment compared to both the healthy and unhealthy plant-based diets. That means that anyone choosing to cut back on animal products, no matter what type of plant-based diet they follow, is going to benefit the environment. However, the study found that there is an additional environmental and health benefit for focusing on minimally processed, healthful foods. The group consuming more healthy plant foods, which the researchers defined as whole grains, fruits, vegetables, nuts, legumes, vegetable oils, tea and coffee, had better health outcomes AND a lower impact on the environment. The group eating the unhealthy plant-based foods, which the study defined as fruit juices, sugar-sweetened beverages, refined grains, potatoes, and sweets, did have lower greenhouse gas emissions than the group eating more animal-based foods. That’s because the unhealthy plant-based foods lead to more cropland and fertilizer use than the healthy plant-based foods. The healthy plant-based foods also lead to lower rates of heart disease, diabetes, and cancer.
The bottom line? If you want to benefit both the planet and your health, center your diet around whole, minimally processed plant foods. Plan meals that are rich in fruits, vegetables, whole grains, nuts and seeds and legumes (or pulses). That means digging into meals like simmered lentils with brown rice and roasted brussels sprouts. A whole grain bowl topped with chickpeas, kale, and tomatoes. And stir-fries with eggplant and tofu. You can still benefit the environment if you occasionally consume some processed plant foods, but try to limit these in a way that is realistic for your lifestyle and food preferences.
You can find the Health Day report on this study here, and the original study from the Lancet Planet Health journal here.
Read more research updates on plant-based, sustainable living here:
IPCC Report: Diet Change Vital to Reduce Climate Impact
What Diet is the Worst for the Environment?
Many Health and Eco Impacts of Food Choices
Eat More Plant Proteins for Longevity
Written by Adele Secrest, Dietetic Intern, with Sharon Palmer