Diet quality and risk and severity of COVID-19: a prospective cohort study

Abstract

ObjectivePoor metabolic health and unhealthy lifestyle factors have been associated with risk and severity of COVID-19, but data for diet are lacking. We aimed to investigate the association of diet quality with risk and severity of COVID-19 and its interaction with socioeconomic deprivation.DesignWe used data from 592 571 participants of the smartphone-based COVID-19 Symptom Study. Diet information was collected for the prepandemic period using a short food frequency questionnaire, and diet quality was assessed using a healthful Plant-Based Diet Score, which emphasises healthy plant foods such as fruits or vegetables. Multivariable Cox models were fitted to calculate HRs and 95% CIs for COVID-19 risk and severity defined using a validated symptom-based algorithm or hospitalisation with oxygen support, respectively.ResultsOver 3 886 274 person-months of follow-up, 31 815 COVID-19 cases were documented. Compared with individuals in the lowest quartile of the diet score, high diet quality was associated with lower risk of COVID-19 (HR 0.91; 95% CI 0.88 to 0.94) and severe COVID-19 (HR 0.59; 95% CI 0.47 to 0.74). The joint association of low diet quality and increased deprivation on COVID-19 risk was higher than the sum of the risk associated with each factor alone (Pinteraction=0.005). The corresponding absolute excess rate per 10 000 person/months for lowest vs highest quartile of diet score was 22.5 (95% CI 18.8 to 26.3) among persons living in areas with low deprivation and 40.8 (95% CI 31.7 to 49.8) among persons living in areas with high deprivation.ConclusionsA diet characterised by healthy plant-based foods was associated with lower risk and severity of COVID-19. This association may be particularly evident among individuals living in areas with higher socioeconomic deprivation.

Association between severity of COVID-19 symptoms and habitual food intake in adult outpatients

“… 48 In contrast, in populations with reduced polysaccharide intake, potentially opportunistic pathogens are increased, such as Escherichia coli and total Enterobacteriaceae. 7 A recent study by Merino et al 49 found that a dietary pattern characterised by healthy plant foods was associated with lower risk and severity of COVID-19…”

Foods to deliver immune-supporting nutrients

“…In this regard, studies of fruit juice and of an encapsulated concentrate of fruits and vegetables reported improvements in immune biomarkers [ 75 , 76 , 77 ] and a decrease in respiratory illness [ 77 , 78 ]. Recent studies have reported relationships between dietary patterns and susceptibility to, or severity of, COVID-19 [ 79 • , 80 • ].…”

“…Merino et al [ 79 • ] used data from 592 571 users of a smartphone-based COVID-19 symptom app which also collected dietary information via a short food frequency questionnaire. The authors assessed diet quality using a ‘plant-based diet score’, which emphasises healthy plant foods such as fruits and vegetables.…”

Microbiota and Its Impact on the Immune System in COVID-19—A Narrative Review

“…According to Conte et al [ 45 ], numerous variables may influence the lung microbiota, including the composition of commensal bacteria and host immune response: lifestyle, diet, smoking, and use of certain drugs, including antibiotics and corticosteroids. A recent prospective study [ 46 ] showed that patients with a fiber-enriched diet better recover from COVID-19. It might be related to gut microbiota mediated systematic immunoregulation, through SCFA, which is also responsible for an anti-inflammatory response.…”