Nutritional LCA – what is it and what can it be used for?

There is an increasing interest in introducing nutrition and health aspects in the assessment of the environmental impact of foods. A suggested method to do it is called nutritional LCA. Through nutritional LCA, it is possible for actors in the food system to include a more holistic sustainability perspective of foods.

Lifecycle assessment (LCA) is a standard method used to evaluate the environmental impact of a product. In the case of foods, the results are often expressed as ”environmental impact per kg product”. Recently, interest has grown on methods that allow to even relate the environmental impact to a food’s nutritional quality or health effect, which is thought to be more in line with a food main function (i.e. to provide nutrients). One such method is nutritional LCA (n-LCA).

To understand more about what nutritional LCA is and how it can be used, I asked some questions to my colleague Marta Bianchi, who is a researcher in the RISE competence area sustainable nutrition, with expertise in nutritional LCA.

First, why is it interesting to combine food impact on health and environment?

- Integration of these two dimensions is the core of the competence area sustainable nutrition and allows to identify required changes, at product, meal or diet level, to optimize nutritional quality or health impact whilst minimizing environmental impacts. In simpler words, the goal is to identify win-win solutions to facilitate food systems transition in a sustainable and healthy direction.

So, nutritional LCA is a tool that can be used to guide towards win-win solutions for environment and health?

- Yes, nutritional LCA is a method where nutrition, health and environmental assessments are integrated. A common approach is to use a measure of nutritional quality as the functional unit. The functional unit is the reference amount of food, for which the environmental impact is estimated. This measure can be as simple as the amount of a single nutrient, for example protein content. However, a nutritional functional unit can also be based on more complex scores where multiple nutrients and food components are considered, often a measure of nutrient density.

- I often use a simple example to clarify the concept of a nutritional functional unit. If we compared the climate impact of carrot and red meat on a weight basis, for example per 100 g, meat would have approximately 175 times higher environmental impact, compared to carrots. However, if we compared these two foods using iron content as the functional unit, the relative environmental impact of meat would be lower and only 13 times higher compared to carrots.

Based on the example above, I understand that the choice of nutritional functional will greatly affect the results when comparing the relative environmental impact of foods. Can you elaborate a bit on this?

- Yes, the choice of nutrient-based functional unit is key! This is an area of active research, and the number of articles addressing the methodological aspects around the choice of a suitable functional unit is increasing every year.

- From a public health perspective, researchers often point to the importance to include nutrients that can be deficient in the diet when identifying the most appropriate nutrient score to be used as functional. For example, a priority micronutrient-focused functional unit was recently introduced by researchers at University of Ottawa, University of California and Global Alliance for Improved Nutrition where the nutrients at highest risk for deficiency globally are considered. In their case, vitamin A, vitamin B12, folate, calcium, iron, zinc, were the prioritized nutrients.

At RISE we have done some research on a Swedish tailored nutritional score. Can you give some details on this?

- Yes, in collaboration with Gothenburg University, RISE has developed and validated a version of the Nutrient Rich Foods-score which is suitable to be used as nutritional functional unit and tailored to the Swedish population. This index, called NRF11.3, includes eleven nutrients that many of us in Sweden should eat more of and three nutrients that we should limit the intake of. For example, the Swedish adapted NRF11.3 includes vitamin D and folate, which are nutrients at risk for deficiency in Sweden.

Given that key nutrients can vary greatly between regions and countries, and that foods also have different roles in the diet, it seems challenging to standardize the methodology for n-LCA?

- Yes, indeed. Although research is progressing, there is still no harmonized and standardized methodology to conduct a nutritional LCA. The most comprehensive collection of best practices is available in a report from a FAO-coordinated expert group where I and Elinor Hallström from RISE participated.

- While the challenges should not be neglected, there are still potential benefits of upgrading traditional food LCA with the nutritional perspective through nutritional LCA. However, for best performance the nutritional LCA should be grounded on a multidisciplinary team where LCA practitioner, nutrition expert and food scientist closely collaborate.

- If performed properly, nutritional LCA offers possibilities to include a more holistic sustainability perspective in strategic work, product development and communication of foods.