The difference in the dietary inflammatory index, functional food, and antioxidants intake between COVID -19 patients and healthy persons

BACKGROUND: The healthy diet is important to maintain immunity against infection. This study aimed to assess and compare the consumption of functional foods, some antioxidants, and dietary inflammatory index between Iranian COVID-19 patients and healthy persons. METHODS: This case-control study was conducted between 1000 (500 cases and 500 controls) adults aged 18–65years in Iran, that were sampling based on the snowball method and their information was collected electronically. The dietary intake was assessed using the Food Frequency Questionnaire (FFQ). RESULTS: There was a significant difference (p = 0.044) in vitamin D consumption between healthy people and COVID-19 patients. Vitamin E intake in healthy participants was significantly (p = 0.041) more than COVID-19 patients. There was a significant difference in Zinc (p = 0.011), selenium (p = 0.021), and vitamin C (p = 0.023) between healthy persons and COVID-19 patients. Healthy participants’ consumption of onion (56.5±7.82 g/day), garlic (4.32±0.01 g/day) and oat (6.32±0.71 g/day) was significantly (p≤0.05) more than COVID-19 patients. With the increase of each unit in the score of the dietary inflammatory index, the risk of COVID-19 incidence increased 1.63 times (OR = 1.63 95% CI: 1.54–1.72). There was an inverse association between the consumption of antioxidants and functional foods with the risk of COVID-19 incidence in the study population (p≤0.05). CONCLUSION: Healthy people consumption of antioxidants and functional foods was more than COVID-19 patients and there was a significant inverse association between the risk of COVID- 19 incidence with the consumption of functional foods and antioxidants. Increasing the dietary inflammatory index score increased the risk of COVID- 19 incidence. There is a need for further clinical trials to confirm the effect of consuming functional foods and antioxidants on the prevention or treatment of COVID-19.