What You Eat May Affect Risk and Severity of COVID-19

A healthy plant-based diet was linked to a lower risk of getting COVID-19 and, in people with COVID-19, a lower risk of experiencing severe symptoms. There was a synergistic association between poor nutrition and increased socioeconomic deprivation with COVID-19 risk exceeding the sum of risk associated with each factor alone.

While metabolic conditions such as obesity and type 2 diabetes have been associated with an increased risk of COVID-19, as well as an increased risk of experiencing severe symptoms after infection, the impact of diet on these risks is unknown. In a recent study led by researchers at Massachusetts General Hospital (MGH) and published in Gut, people whose diets were based on healthy plant foods had a lower risk on both counts. The beneficial effects of diet on COVID-19 risk seemed particularly relevant in individuals living in areas of high socioeconomic deprivation.

“Previous reports suggest that poor nutrition is a common feature of groups disproportionately affected by the pandemic, but data on the link between diet and the risk and severity of COVID-19 is lacking,” said lead author Jordi Merino, PhD, a research associate. at the Diabetes Unit and Center for Genomic Medicine at MGH and a lecturer in medicine at Harvard Medical School.

For the study, Merino and his colleagues examined data from 592,571 participants in the smartphone-based COVID-19 Symptom Study. The participants lived in the UK and US and were recruited from March 24, 2020 and followed until December 2, 2020. At the start of the study, participants completed a questionnaire asking about their dietary habits before the pandemic. Diet quality was assessed using a healthy Plant-BasedDiet score that emphasizes healthy plant foods such as fruits and vegetables.

During follow-up, 31,831 participants developed COVID-19. Compared to individuals in the lowest quartile of the nutritional score, those in the highest quartile had a 9% lower risk of developing COVID-19 and a 41% lower risk of developing severe COVID-19. “These findings were consistent across a series of sensitivity analyzes that take into account other healthy behaviors, social determinants of health, and community virus transmission rates,” Merino says.

“While we cannot overemphasize the importance of getting vaccinated and wearing a mask in crowded indoor environments, our research suggests that individuals may also be able to reduce their risk of contracting COVID-19 or poor outcomes by paying attention to their diet.” said co-senior author Andrew Chan, MD, MPH, a gastroenterologist and chief of the clinical and translational epidemiology division of MGH.

The researchers also found a synergistic link between poor nutrition and increased socioeconomic deprivation with COVID-19 risk exceeding the sum of risk associated with each factor alone.

“Our models estimate that nearly a third of COVID-19 cases would have been prevented if one of the two exposures — diet or deprivation — were not present,” says Merino.

The results also suggest that public health strategies that improve access to healthy food and address social determinants of health could help reduce the burden of the COVID-19 pandemic.

“Our findings call on governments and stakeholders to prioritize healthy nutrition and wellness with impactful policies or else we risk losing decades of economic progress and a substantial increase in health inequalities,” said Merino.

Reference: “Diet Quality and Risk and Severity of COVID-19: A Prospective Cohort Study” by Jordi Merino, Amit D Joshi, Long H Nguyen, Emily R Leeming, Mohsen Mazidi, David A Drew, Rachel Gibson, Mark S Graham, Chun-Han Lo, Joan Capdevila, Benjamin Murray, Christina Hu, Somesh Selvachandran, Alexander Hammers, Shilpa N Bhupathiraju, Shreela V Sharma, Carole Sudre, Christina M Astley, Jorge E Chavarro, Sohee Kwon, Wenjie Ma, Cristina Menni, Walter C Willett , Sebastien Ourselin, Claire J Steves, Jonathan Wolf, Paul W Franks, Timothy D Spector, Sarah Berry and Andrew T Chan, September 6, 2021, Gut.
DOI: 10.1136 / gutjnl-2021-325353

The study was co-led by researchers from Kings College London. Co-authors include Amit D Joshi, Long H Nguyen, Emily R Leeming, Mohsen Mazidi, David A Drew, Rachel Gibson, Mark S Graham, Chun-Han Lo, Joan Capdevila, Benjamin Murray, Christina Hu, Somesh Selvachandran, Alexander Hammers, Shilpa N Bhupathiraju, Shreela V Sharma, Carole Sudre, Christina M Astley, Jorge E Chavarro, Sohee Kwon, Wenjie Ma, Cristina Menni, Walter C Willett, Sebastien Ourselin, Claire J Steves, Jonathan Wolf, Paul W Franks, Timothy D Spector, Sarah Berry and Andrew T Chan.

The study was funded by the National Institutes of Health, the National Institute for Health Research, the UK Medical Research Council/Engineering and Physical Sciences Research Council, the Wellcome Trust, the Massachusetts Consortium on Pathogen Readiness, the American Gastroenterological Association, the American Diabetes Association, the Alzheimer’s Society and Zoe Ltd.