Nutrient density and food quality in the context of regenerative agriculture

The connection between regenerative agriculture and food quality is explored in this report.

“Although direct evidence is limited, there is strong suggestions from the broader scientific literature that there are likely to be impacts of regenerative agriculture on food ‘nutrient density’. However, the extent of this remains to be determined in a New Zealand context,” says Dr Carolyn Lister, principal scientist and science team leader at Plant & Food Research, and author of the report Determining food quality in the context of regenerative agriculture.

The ‘nutrient density’ concept typically expresses the nutrient content of foods based on a reference amount, such as’mg per 100g’ or’%RDA per 100g’ but we don’t always eat foods in equal amounts.

Health benefits may also come from the diversity of phytochemicals present. There is evidence that soil quality, applied nutrients (particularly nitrogen), and farming system choices affect not just yield and nutritional composition, but also phytochemical composition in reasonably consistent ways. The report notes that phytochemical composition and concentrations vary much more than the core nutrients and are influenced by more than farm management.

“It is likely to be essential to measure a broad range of nutrients and phytochemicals to determine if regenerative agriculture can improve the quality of New Zealand foods and, ultimately, diets,” says Dr Lister.

The report also examines the validity of chlorophyll and Brix as indicators of food quality or nutrient density, since they are commonly used by the regenerative agriculture community. The relationship between chlorophyll and phytochemical concentrations in a plant is unclear, and also highly unlikely, says the report. There is some value in measuring Brix in some crops but this needs further validation, as there is no solid scientific evidence that Brix values alone can be used to describe a food’s nutritional value.

Critical work is needed to assess the impacts of RA on food quality and safety in a New Zealand context. One of the premises of RA is that it can produce each individual food item at a higher quality, in particular, more nutrient dense. This needs to be substantiated through robust testing. The testing required will differ by crop and it will also be essential to consider what tool might be used to assess nutrient density (i.e. which profiling scoring system to use as to what domains should be captured). It will be important to test whether the nutrient/phytochemical concentrations in different individual farm produce is higher when produced under RA. Once that is determined and shown to differ, then nutrient profiling scores (such as Food Compass) could be used to compare an identical basket of foods (with quantities in proportion to their average consumption in a balanced diet). produced from RA or from ‘conventional’ agriculture. Other aspects of production can then be layered on to this to evaluate the wider aspects of quality and ensure economically sustainable production.