Eating fruits and vegetables is better for your health… But also for the planet. Scientists have analyzed some 57,000 products sold in supermarkets in the United Kingdom and Ireland, in a large study published Monday by the scientific journal Pnas. They find that crisps and sugary drinks have a very low environmental impact, unlike cheese meat.
The researchers, who hope their study can help consumers shop more sustainably without sacrificing anything to their health, also cross-referenced their results with the nutritional qualities of these foods.
More sustainable, often more nutritious products
Syrups, sodas or other fruit juices are thus among the products sold with the lowest environmental impact – because they are mostly composed of water – but their nutritional quality is poor, points out the study. However, researchers believe that in general, the most sustainable products are also the best from a nutritional point of view. This work thus confirms what other studies had already advanced by analyzing single ingredients (fruits, red meat, etc.). The novelty is that the analysis here concerns products made up of multiple ingredients (sauces, prepared meals, etc.).
The task is difficult because the quantity of each ingredient is considered a trade secret, and therefore not very detailed: only about 3% of the more than 57,000 products, sold by eight food retailers, had a completely quantified composition. The scientists therefore developed an algorithm based on the few known pieces of information to assess the proportion of missing ingredients – in the United Kingdom and Ireland, the components are notably listed in order of quantity used.
Assess the environmental impact
To assess the environmental impact, four factors were taken into account: greenhouse gas emissions, use of limited water resources, land use, and aquatic eutrophication (pollution of water).
Bread, but also certain cereals, certain prepared meals or desserts (cakes, biscuits, etc.) have a relatively low or intermediate environmental impact. On the other hand, fish, cheese and meat, especially red meat (lamb, beef) have a strong impact. “Replacing meat, dairy and eggs with plant-based alternatives could have great environmental benefits,” note the study authors.
But “smaller” transitions can also help. For example, beef lasagna, with a strong environmental impact, could be replaced by chicken or pork lasagna, or even vegetarian. In the future, better knowing the dosages and the origin of the different ingredients would help to determine more precisely their impact on the environment, note the researchers.