October 29, 2019
A new, wide-ranging study attempted to construct a complete picture on two often-studied topics, and found that diets which emphasize healthier eating are also usually better for the environment.
The study, published this week in the journal "Proceedings of the National Academy of Sciences", attempted to reconcile humans' collective diet choices with the way those choices affect the environment. Researchers examined the way 15 different foods and food types affect specific parts of our health, and also the way the foods and food types affect specific parts of the environment.
Here's what the researchers examined:
• Foods: whole grains, refined grains, fruits, vegetables, nuts, legumes, potatoes, fish, dairy, eggs, chicken, unprocessed red meat, processed red meat, sugar-sweetened beverages, and olive oil
• Health outcomes: total mortality, coronary heart disease, colorectal cancer, diabetes, stroke
• Environmental outcomes: Scarcity-weighted water use; acidification, or the changing of the oceans' pH balance; eutrophication, or the over-enriching of bodies of water; land use; and greenhouse gas emissions
The study then plotted each relationship into a spider chart, not unlike the ones used by football teams for prospects, in order to visualize the data better. You can find the charts here.
The researchers found that foods like whole grains and fruits had fewer adverse effects on both individual human health and environmental health, while foods like unprocessed red meat and processed red meat had the opposite relationship.
Interestingly, the data wasn't entirely one-sided data. Legumes, while largely healthier in terms of health outcomes, require greater land use and water use than sugar-sweetened beverages, and also contribute more to acidification.
But ecologist David Tilman, who worked on the study, told NPR that even in the case of healthy foods with seemingly larger environmental impacts than unhealthy foods, "if water is going to be used to irrigate crops, it would seem better for it to be used to grow healthy crops."
The researchers hope that, on top of showing the average consumer the effects of their everyday diet choices, the study can also inform policy makers and food companies to "better understand the multiple health and environmental implications of food choices" in the future.
"The same dietary changes that could help reduce the risk of diet-related noncommunicable diseases could also help meet international sustainability goals," the study's authors wrote in their conclusion section.