A new study led by the University of Oxford has evaluated the environmental impacts of over 57,000 food products that people consume on a daily basis. While many previous studies have assessed the environmental impact of food commodities such as fruits, wheat, or beef, most food products contain a variety of different ingredients that all have an impact on the environment during processes of production, harvesting, transporting, and processing. Better understanding the environmental footprint of each of these processes and ingredients could enable the transition to a more sustainable food system, while also improving people’s health.
“The goal is to have a simpler, and more rigorous quantitative way to inform consumers about the tens of thousands of different items they might buy in a grocery store,” said study co-author David Tilman, an ecologist at the University of California, Santa Barbara.
The analysis revealed that beef and lamb take the greatest toll on the environment, with impacts far superseding those of other products on the higher end of the environmental impact scale, such as chicken, fish and seafood, or nuts. By contrast, plant-based grocery foods like rice or flat-breads, as well as processed drinks such as sodas or energy drinks were rated at the lowest impact level among the food products that were assessed.
According to the scientists, diets that include healthy, less processed foods also tend to be healthier for the environment. Thus, plant-based foods are on the healthier end of the scale for both humans and the environment, while highly-processed grains or dairy products verge towards the less-healthy end.
“The healthiest diets that we know of are variants on the classical Mediterranean diet, which has many servings of fruits and vegetables a day, and whole grains,” Dr. Tilman explained. “Whole grain has the advantage of having fiber, which helps slow the rate at which starch becomes sugars.” Other healthy, nutritious, and environmentally-friendly diets include vegetarian and pescatarian diets.
Further research is needed to refine the scientists’ assessment, since there is a lot of variability in the proportion and type of ingredients in similar foods, which can lead to differences in health and environmental impacts. However, if more comprehensive information about the impacts of food products on both human health and the environment becomes more widely available, consumers will be able to make better, more informed choices for their diets.
“I hope this information ends up on packages. And I hope because it’s on packages that companies that make different foods will willingly tell us the exact ingredients and amounts in their foods, so we can give the most rigorous, honest evaluation of their product,” Dr. Tilman concluded.
The study is published in the journal Proceedings of the National Academy of Sciences.