Healthy diets have never been more important. We can prolong our own longevity and also help slow climate change, conserve natural resources, reduce pollution and make other changes to make life on Earth more sustainable.
A 2019 study by American and British researchers found a strong correlation between healthy and sustainable diets. Among its findings:
- Out of the foods considered to have a positive effect on health, fruits, vegetables, whole grains, legumes, nuts and olive oil were found to have among the lowest environmental impacts of all foods.
- Fish has considerably more potential for harm, equivalent to poultry and dairy, but is still far below red meat and processed red meat’s demands on resources and effects on the environment.
- Producing a serving of processed or unprocessed red meat, which can have negative health effects, has 10 to 100 times more of an effect on greenhouse gas emissions, land use and harm to marine habitats than plant-based foods.
Other research has produced more specific data about individual foods’ environmental impact to give people a more granular view of their food choices. Some very healthy foods have more environmental costs than you might expect, and other beneficial foods are a more sustainable choice.
- Asparagus is No. 6 among 10 “climate-changing” common foods ranked by the Natural Resources Defense Council based on greenhouse gas emissions, higher than pork, veal, chicken and turkey. Broccoli is a frequently suggested substitute for this veggie, has 22% of the carbon footprint of asparagus (much of which is imported from South America) and requires about 13% as much water.
- Nuts and seeds are commonly grouped together when food groups are considered but vary widely in the amount of water required to grow them. Pistachios, almonds and walnuts come from trees and consume much more water than seeds taken from smaller plants or peanuts, which are grown underground.
- Salmon is possibly the healthiest animal product available on the market, but conventional penned salmon farms present significant environmental challenges through their use of chemicals, disease spread and nitrogen deposits in the water they use. More sustainable seafood choices include wild-caught or tank-farmed salmon, Arctic char or oily fish including herring and mussels, according to the Environmental Defense Fund.
- Coffee is everybody’s favorite morning picker-upper and has laudatory health benefits, but tends to score low on sustainability for increasingly being grown in full-sun conditions to increase production and leading to deforestation, as well as high water use. Tea in comparison is greener in terms of water and land use, though tea plantations do contribute to deforestation as well.
Making crop-to-crop comparisons at the global level doesn’t account for regional differences. Most food producers are working to make their products more sustainable through measures like water conservation or reducing greenhouse gas emissions, so it’s a good idea to stay updated on their advances.