Minimally Processed Foods Have a Higher Total Antioxidant Content Compared to Processed and Ultra-processed Foods: Results from an Analysis of 1,946 Food Items

Abstract

Ultra-processed foods (UPF), per the NOVA Classification, provide a major source of calories within modern food systems and are associated with poor health outcomes related to chronic inflammation. Dietary antioxidants play a key role in preventing disease, however, the relationship between the NOVA Classification and the total antioxidant content (TAC) of foods is not well-characterized. We hypothesized that TAC would be highest in Minimally Processed (MPF), lower in Processed (PRF), and lowest in UPF. TAC data for 3,137 animal-based, mixed, and plant-based food items were obtained from a published data set. After data cleaning, 1,946 food items and their TAC values were analyzed using two hierarchal linear models (alpha: p<0.05). MPF had the highest mean TAC (10.79 ± 0.87 mmol/100g) and were 11.31-fold and 10.72-fold higher than PRF and UPF, respectively (p=0.023). Plant-based and Mixed foods had a higher mean TAC (8.55 ± 0.68 and 1.12 ± 0.11 mmol/100g, respectively) and were 22.67-fold and 2.98-fold higher compared to animal-based foods (p<0.001). Food processing did not change mean TAC in Mixed and Animal-based foods; however, plant-based MPF had a higher mean TAC (11.49 ± 0.93 mmol/100g) and were 9.88-fold and 15.12-fold higher compared to plant-based PRF and UPF, respectively (p<0.001). Mean TAC differed between NOVA processing groups for three categories of food: Vegetables, Beverages, and Beans, Nuts & Seeds (p<0.001). Across all food items, and especially plant-based foods, mean TAC decreased with food processing. The lower TAC of UPFs may at least partially explain why their consumption promotes inflammatory chronic disease.