Lower risk for and severity of COVID-19 was associated with a diet rich in healthy plant-based foods, according to a study published in Gut

Investigators used data from the smartphone-based COVID-19 Symptom Study to collect diet information for the prepandemic period and assessed diet quality using a healthful Plant-Based Diet Score (hPBDS). Hazard ratios (HR) for COVID-19 risk were determined using multivariable models and COVID-19 severity was defined using a validated symptom-based algorithm or by hospitalization requiring oxygen support.

Overall, data from 592,571 participants were included, representing 3,886,274 person-months of follow-up. A total of 31,815 COVID-19 cases were documented.

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For participants in the highest and lowest quartiles of hPBDS, the crude COVID-19 rates per 10,000 person-months were 72.0 (95% CI, 70.4-73.7) and 104.1 (95% CI, 101.9-106.2), respectively. After adjusting for potential confounders, individuals with a healthier diet had a lower risk for COVID-19 compared against individuals with lower quality diet (HR, 0.91; 95% CI, 0.88-0.94). In the adjusted model, high quality diet, when compared with low quality diet, was associated with lower risk for severe COVID-19 as well (HR, 0.59; 95% CI, 0.47-0.74).

A stratified analysis found a more evident inverse association between diet quality and COVID-19 risk in areas of high socioeconomic deprivation. The combined association of socioeconomic deprivation and low-quality diet was higher than for each factor separately (Pinteraction =.005). When comparing individuals in the lowest versus highest quartile of diet score, the absolute excess COVID-19 rate per 10,000 person-months was 22.5 (95% CI, 18.8-26.3) for those living in areas of low socioeconomic deprivation and 40.8 (95% CI, 31.7-49.8) for those living in areas of high socioeconomic deprivation.

Due to its observational nature, this study cannot indicate causal effects. Additionally, the study population is not a random sample and there was homogeneity among patient demographics. Finally, there exists potential for bias and measurement error due to the time lapse between the dietary recalls and self-reporting nature of data collection.  

Researchers concluded, “Our findings suggest that public health interventions to improve nutrition and poor metabolic health and address social determinants of health may be important for reducing the burden of the pandemic.”

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures


Merino J, Joshi AD, Nguyen LH, et al. Diet quality and risk and severity of COVID-19: a prospective cohort study. Gut. 2021;70(11):2096-2104. doi: 10.1136/gutjnl-2021-325353

This article originally appeared on Endocrinology Advisor