Minimally processed foods have a higher total antioxidant content compared to processed and ultra-processed foods: results from an analysis of 1946 food items

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 characterised. We hypothesised that TAC would be highest in minimally processed food (MPF), lower in processed food (PRF) and lowest in UPF. TAC data for 3137 animal-based, mixed and plant-based food items were obtained from a published dataset. After data cleaning, 1946 food items and their TAC values were analysed using two hierarchal linear models (alpha: P < 0<middle dot>05). MPF had the highest mean TAC (10<middle dot>79 (sem 0<middle dot>87) mmol/100 g) and were 11<middle dot>31-fold and 10<middle dot>72-fold higher than PRF and UPF, respectively (P = 0<middle dot>023). Plant-based and mixed foods had a higher mean TAC (8<middle dot>55 (sem 0<middle dot>68) and 1<middle dot>12 (sem 0<middle dot>11) mmol/100 g, respectively) and were 22<middle dot>67-fold and 2<middle dot>98-fold higher compared with animal-based foods (P < 0<middle dot>001). Food processing did not change mean TAC in mixed and animal-based foods; however, plant-based MPF had a higher mean TAC (11<middle dot>49 (sem 0<middle dot>93) mmol/100 g) and were 9<middle dot>88-fold and 15<middle dot>12-fold higher compared with plant-based PRF and UPF, respectively (P < 0<middle dot>001). Mean TAC differed between NOVA processing groups for three categories of food: vegetables, beverages and beans, nuts and seeds (P < 0<middle dot>001). Across all food items, and especially plant-based foods, mean TAC decreased with food processing. The lower TAC of UPF may at least partially explain why their consumption promotes inflammatory chronic disease.