A new study of frontline healthcare workers across six countries shows an association between plant-based diets and reduced risk of developing moderate or severe Covid-19. The study also found lower odds with pescatarian diets, though to a lesser extent compared to vegans, suggesting that there could be a link between symptom severity and dietary choices.
Researchers in a new study published in the journal BMJ Nutrition Prevention & Health have found that plant-based or fish diets may help lower the severity of Covid-19 infection. The study involved more than 2,800 healthcare professionals in France, Germany, Spain, Italy, the U.K. and U.S. who were part of the Survey Healthcare Globus network.
Plant-based diets were associated with a 73% reduction in the incidence of moderate to severe disease from Covid-19, while pescatarian diets were linked to a 59% reduction.
Interestingly the study also showed that those practicing a low-carbohydrate, high-protein diet had nearly four-times the odds of moderate to severe infection from Covid-19.
These findings were based on an online survey conducted between July and September 2020, which questioned respondents’ food frequency with 47 different items and the severity of the infections they had experienced using objective criteria.
It also collected data on participants’ personal backgrounds, medical history, use of medication and lifestyle, such as physical activity levels and smoking habits, to account for other confounding factors. The findings held true after factoring in BMI and co-existing medical conditions as well.
Importantly, the association is centred on the risk of developing severe symptoms after contracting Covid-19, rather than the direct risk of contracting the disease itself or the length of the subsequent illness.
Researchers believe that the correlation could be explained by the likelihood that plant-based diets are more nutrient-rich, especially in phytochemicals, vitamins and minerals that can be found in fruits and vegetables and are linked to building up a healthy immune system.
“Our results suggest that a healthy diet rich in nutrient dense foods may be considered for protection against severe Covid-19,” concluded the team of researchers hailing from several universities and research institutes across the U.S., including Johns Hopkins University, Envision Health Partners, Cedars-Sinai Medical Center, Stamford Hospital among others.
Commenting on the findings, Professor Gunter Kuhnle of the University of Reading, who was not involved in the research, said: “Since the beginning of the pandemic, there has been a lot of speculation about the impact of diet on disease risk.”
While noting that caution must be taken when interpreting observational and self-reported data, Dr. Kuhnle highlighted that the findings were “not surprising” given that “people who follow a mainly plant-based diet or eat fish are often healthier when compared to a control group with a “normal” diet.”
“An interesting – and for some surprising – finding is the higher risk found in those following a low-carbohydrate diet,” Dr. Kuhnle continued. “The same limitations as above apply of course – and there are widely differing interpretations of “low carb”, but the data suggest that those following such a diet have a higher risk of Covid-19.”
Read: NIH study finds plant-based high-carb diets more effective for weight loss than low-carb high-protein diets
Other experts who were not affiliated with the study sharing their views with Medical News Centre voiced similar worries about establishing any conclusions about a firm link between dietary habits and Covid-19 severity risk, but did highlight there is a bed of research to support that plant-forward diets are associated with better overall health.
“Diets based on high levels of plant foods and low levels of meat are associated with lower risks of several non-infectious conditions, including cardiovascular disease and some types of cancer,” said nutrition researcher Dr. Ian Johnson of the Quadram Institute Bioscience.