Researchers from a number of prominent institutions sought to answer the question: what, if anything, does diet have to do with the fact that when it comes to COVID-19, some people face severe and even life-threatening illness while with others, it’s barely perceived as a common cold? What’s behind these observations from the standpoint of diet and health? While, of course, age and the presence of morbidities clearly surface in the mortality rate but what about the huge differences in cases? As it turns out, a study involving front-line COVID-19 care providers spanning six nations revealed some striking data points that should be further studied. Those healthcare professionals consuming a plant-based diet were 73% less likely to succumb to moderate to severe COVID-19 infection while individuals eating a plant and/or fish-based diet turned out to be 59% less likely to become severely ill with the novel coronavirus.
Published recently in BMJ Nutrition, Prevention & Health, these study team authors concluded, “Our results suggest that a healthy diet rich in nutrient-dense foods may be considered for protection against severe COVID-19.”
This observational, survey-based study covered 2,884 doctors and nurses working with COVID-19 patients in a number of countries including the United States, United Kingdom, Germany, France, Italy, and Spain, where the investigators sought to uncover any seeming association with the subjects’ self-reported diets and levels of COVID-19 severity, duration of symptoms, etc. Of the whole study group, 2,316 of the cohort served as a study group in that they hadn’t experienced any SARS-CoV-2 symptoms nor had they tested in the affirmative for the pathogen.
In the meantime, the study sponsors used the other cohort involving 568 participants who struggled with symptoms associated with the coronavirus or produced a positive COVID-19 test. Of this total, 138 of them shared that they experienced moderate to severe conditions associated with the coronavirus while the remaining study cohort’s population reported only very mild to mild cases.
Of course, the study sponsors factored in a number of elements from weight and body mass index to age, ethnicity, a profession in healthcare and commodities as well as lifestyle elements such as smoking and proclivity to exercise.
The researchers introduced a diet panel, that is, a number of meal types totaling 11 selections that most closely followed their own particular lifestyle choices when it comes to meals during the past year. The research team was able to take the subject input and combine it into groupings that include plant-based or vegetarian diets, and the like.
Of interest, the study team found that for example, those who consumed low carb and high protein diets (think like Atkins or Zone Diet) experienced four times more the cases of moderate to severe COVID-19 symptoms.
Overall, those study participants that have plant-based diets or pescatarian diets are associated with less risk of moderate to severe COVID-19. While there isn’t enough data from this study to prove a correlation, the results are nonetheless intriguing and merit additional study.
The study was funded by Survey Healthcare Globus. Hyunju Kim and Casey M. Rebholz are funded by grants from the National Institute of Diabetes and Digestive and Kidney Diseases as well as the National Heart, Lung and Blood Institute outside of the submitted work. Susan Cheng received funding from the National Institutes of Health.
Of course, there are a number of limitations with this study. An observational survey with a small size for such a class of study and dependence on subjects self-reporting, which is prone for sizeable margins of error in estimates on the true impact of diet on association with COVID-19 illness. Moreover, the authors reported that COVID-19 tests were not always available and in many cases with asymptomatic cases individuals can actually have the disease with no symptoms. This means that some of the subjects could have improperly shown up in the control groups, hence impacting study accuracy.
Moreover, while this study shows some association or correlation between the diets identified and the level of SARS-CoV-2 infection severity, it fails to show any causality. There isn’t enough strength in this study to make any conclusions.
- Hyunju Kim, PhD, Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA, Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University, Baltimore, Maryland, USA
- Casey M. Rebholz, PhD, Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA, Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University, Baltimore, Maryland, USA
- Sheila Hedge, MPH, Division of Cardiovascular Medicine, Brigham & Women’s Hospital, Boston, Massachusetts, USA
- Christine LaFiura, Envision Health Partners
- Madhunika Raghavan, Envision Health Partners
- John F. Lloyd, Department of Cardiology, Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
- Susan Cheng, Department of Cardiology, Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
- Sara B. Seidelmann, Department of Medicine, Stamford Hospital, Stamford, Connecticut, USA
- Department of Medicine, Columbia University Vagelos College of Physicians and Surgeons, New York, New York, USA, Corresponding Author