Long-term diet and risk of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and Coronavirus Disease 2019 (COVID-19) severity

Abstract

Background The role of diet on COVID-19 is emerging. Methods We included 42,935 participants aged 55 to 99 years in two ongoing cohort studies, Nurses’ Health Study II and Health Professionals Follow-up Study, who completed a series of COVID-19 surveys in 2020 and 2021. Using data from food frequency questionnaires prior to COVID-19, we assessed diet quality using the Alternative Healthy Eating Index (AHEI)-2010, the alternative Mediterranean Diet (AMED) score, an Empirical Dietary Index for Hyperinsulinemia (EDIH), and an Empirical Dietary Inflammatory Pattern (EDIP). We calculated multivariable adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) for SARS-CoV-2 infection and severity of COVID-19 after controlling for demographic, medical, and lifestyle factors. Results Among 19,754 participants tested for SARS-CoV-2, 1,941 participants reported a positive result. Of these, 1,327 reported symptoms needing assistance and another 109 were hospitalized. Healthier diet, represented by higher AHEI-2010 and AMED scores and lower EDIH and EDIP scores, were associated with lower likelihood of SARS-CoV-2 infection (ORs Q (quartile) 4 vs. Q1 (95%CI) were 0.80 (0.69, 0.92) for AHEI-2010; 0.78 (0.67, 0.92) for AMED; 1.36 (1.16, 1.57) for EDIH; and 1.13 (0.99, 1.30) for EDIP; all p for trend ≤ 0.01). In the analysis of COVID-19 severity, participants with healthier diet had lower likelihood of severe infection and were less likely to be hospitalized due to COVID-19. However, associations were no longer significant after controlling for BMI and pre-existing medical conditions. Conclusion Diet may be an important modifiable risk factor for SARS-CoV-2 infection, as well as for severity of COVID-19. This association is partially mediated by BMI and pre-existing medical conditions.

The effect of adherence to high‐quality dietary pattern on COVID‐19 outcomes: A systematic review and meta‐analysis

“…Five studies involving 4 907 637 individuals (3 149 784 high‐quality diet individuals and 1 757 853 controls) reported the risk of COVID‐19 infection in individuals with high‐quality dietary pattern 4–8,18 . Overall pooled analyses showed a 28% decrease of COVID‐19 infection was associated with high‐quality dietary patterns (RR = 0.72, 95% CI 0.64–0.81, p = 0.00001; Figure 2).…”

“…We identified five studies involving 4 023 663 individuals (3 149 784 high‐quality diet individuals and 873 881 controls) addressing the effects of different high‐quality dietary patterns on COVID‐19 infection and hospitalization (Figure 1 ). Reports were published between 2021 and 2022 using the following experimental designs: three cohorts 6 , 7 , 8 and two cross‐sectional studies. 4 , 5 Except for two cross‐sectional studies, all cohorts reported the prevalence of comorbidity, including hypertension, diabetes mellitus, cardiovascular disease, and pulmonary disease among included individuals.…”

“…The included studies used different types of diet screening and diagnostic tools, including self‐reported questionnaire, 4 , 5 Leeds Short Form Food Frequency Questionnaire, 6 and Mediterranean Diet Score. 7 , 8 Participants’ data range regarding dietary pattern were collected from 1 year, 4 , 5 , 6 4 years, 8 and to 10 years 7 before the pandemic. Association between dietary pattern with COVID‐19 outcomes was evaluated in the included studies using the following strategies: plant‐based diet, 4 , 5 , 6 and Mediterranean diet.…”

“…1,2 It has been demonstrated that nutritional quality and status play a key role in innate and adaptive immunity, and are associated with the pathogenesis and progression of COVID-19, as in other viral infections. 3 Several dietary patterns, which are mostly considered high quality diets, including plant-based diet, [4][5][6] Mediterranean diet, 7,8 pre and probiotic diet, 9 and low-fat diet 10 have been documented to reduce the risk and severity of COVID-19. It is possible for poor diets to induce inflammation and immune system dysfunction, which can disrupt the body's immune system in dealing with respiratory viral infections.…”

“…Several dietary patterns, which are mostly considered high quality diets, including plant‐based diet, 4 , 5 , 6 Mediterranean diet, 7 , 8 pre and probiotic diet, 9 and low‐fat diet 10 have been documented to reduce the risk and severity of COVID‐19. It is possible for poor diets to induce inflammation and immune system dysfunction, which can disrupt the body's immune system in dealing with respiratory viral infections.…”