Plant-based diets, pescatarian diets and COVID-19 severity: a population-based case-control study in six countries.

Hyunju Kim, Casey M Rebholz, Sheila Hegde, Christine LaFiura, Madhunika Raghavan, John F Lloyd, Susan Cheng, Sara B Seidelmann

Journal: BMJ nutrition, prevention & health 2021;4(1):257-266

PMID: 34308134

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Plain Language Summary

Corona virus disease 2019 (COVID-19) is a respiratory tract illness caused by the novel coronavirus, SARS-CoV-2. Obesity, type 2 diabetes, atherosclerotic cardiovascular disease, and hypertension are risk factors for severe COVID-19. The aim of this study was to evaluate the association between self-reported diets and COVID-19 infection, severity, and duration of symptoms. This study is a case–control study of frontline physicians and nurses in six countries. More than 70% of study participants were men and almost 95% of the study participants were physicians. Results indicate that individuals who reported following plant-based diets or pescatarian diets had lower odds of severe COVID-19-like illness. Whereas, individuals who reported following low carbohydrate, high protein diets had higher odds of severe-COVID-19-like illness, when compared with individuals who followed plant-based diets. Authors conclude that a healthy diet rich in nutrient-dense foods may be considered for protection against severe COVID-19.

Abstract

BACKGROUND

Several studies have hypothesised that dietary habits may play an important role in COVID-19 infection, severity of symptoms, and duration of illness. However, no previous studies have investigated the association between dietary patterns and COVID-19.

METHODS

Healthcare workers (HCWs) from six countries (France, Germany, Italy, Spain, UK, USA) with substantial exposure to COVID-19 patients completed a web-based survey from 17 July to 25 September 2020. Participants provided information on demographic characteristics, dietary information, and COVID-19 outcomes. We used multivariable logistic regression models to evaluate the association between self-reported diets and COVID-19 infection, severity, and duration.

RESULTS

There were 568 COVID-19 cases and 2316 controls. Among the 568 cases, 138 individuals had moderate-to-severe COVID-19 severity whereas 430 individuals had very mild to mild COVID-19 severity. After adjusting for important confounders, participants who reported following 'plant-based diets' and 'plant-based diets or pescatarian diets' had 73% (OR 0.27, 95% CI 0.10 to 0.81) and 59% (OR 0.41, 95% CI 0.17 to 0.99) lower odds of moderate-to-severe COVID-19 severity, respectively, compared with participants who did not follow these diets. Compared with participants who reported following 'plant-based diets', those who reported following 'low carbohydrate, high protein diets' had greater odds of moderate-to-severe COVID-19 (OR 3.86, 95% CI 1.13 to 13.24). No association was observed between self-reported diets and COVID-19 infection or duration.

CONCLUSION

In six countries, plant-based diets or pescatarian diets were associated with lower odds of moderate-to-severe COVID-19. These dietary patterns may be considered for protection against severe COVID-19.

Address: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.; Welch Center for Prevention, Epidemiolgy, and Clinical Research, Johns Hopkins University, Baltimore, Maryland, USA.; Division of Cardiovascular Medicine, Brigham & Women's Hospital, Boston, Massachusetts, USA.; Envision Health Partners, Riverside, Connecticut, USA.; Department of Cardiology, Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.; Department of Medicine, Stamford Hospital, Stamford, Connecticut, USA.; Department of Medicine, Columbia University Vagelos College of Physicians and Surgeons, New York, New York, USA.

DOI: 10.1136/bmjnph-2021-000272