Vegetarian and fish-based diets may be associated with lower probabilities of moderate or severe COVID-19 infection, suggesting the results of a six-country survey based on self-reported symptoms. The researchers noted that the survey is observational and does not establish a causal relationship between diet and COVID-19 severity, and care should be taken when interpreting the findings.
The results of a survey published in the journal BMJ Nutrition Prevention & Health on Tuesday indicate that plant- and fish-based diets were associated with 73 percent and 59% lower rates of serious illness, respectively.
Several studies have suggested that diet may play an important role in the severity of symptoms of COVID-19 infection and the duration of the disease.
However, there is little evidence to confirm or disprove this theory.
Researchers from Johns Hopkins School of Public Health in Bloomberg, USA have studied the responses of 2,884 physicians and nurses with high SARS-CoV-2 exposure to COVID-19, COVID-19 virus, working in France (Germany). . , Italy, Spain, United Kingdom and USA.
The online survey, conducted between July and September 2020, was designed to provide accurate information on dietary responses made in the previous year.
It was based on a 47-item questionnaire on food frequency, and surveyed the severity of COVID-19 infections.
The survey also collected information on personal history, medical history, medication use, and lifestyle.
Different diets were combined in plants – higher among vegetables, legumes and nuts, and lower in poultry and red and processed meats – with the addition of fish or seafood to the fish / vegetable and low-carbohydrate protein diets.
568 respondents said they had or did not have symptoms that were consistent with COVID-19 infection, but did test positive for the infection.
About 2,316 said they had no symptoms or no positive results.
Of the 568 cases, 138 clinicians reported moderate or severe COVID-19 infection, and the remaining 430 reported COVID-19 infection as very mild or mild.
The respondents said that plant-based diets came from “or plant-based / fish diets” with 73 to 59 percent and 59% lower rates of moderate and severe COVID-19 infection, respectively.
According to the researchers, those who said they were on a plant-based diet compared to those who said they were on a low-carbohydrate low-protein diet were nearly four times more likely to have a moderate or severe COVID-19 infection.
These associations were true when weight (BMI) and the accompanying health conditions were also taken into account, they said.
However, the researchers found no link between the type of diet and the risk of contracting COVID-19 infection or the length of subsequent illness.
The survey was based on individual memories rather than objective assessments, and the definition of certain dietary patterns may vary by country, the researchers noted.
Men were more likely than women to be in the study, so the findings may not be applicable to women, they added.
However, plant-based diets are high in nutrients, especially phytochemicals, vitamins, and minerals, all of which are important for a healthy immune system, the researchers said.
Fish is also an important source of vitamin D and omega-3 fatty acids, both of which are said to have anti-inflammatory properties.
“Our results suggest a healthy diet rich in dense foods to protect against severe COVID-19,” the researchers noted.
“Trends in this study are limited by study size and design (self-reporting of diet and symptoms), so care must be taken in interpreting the findings,” said Shane McAuliffe, vice president of NNEdPro Nutrition and COVID-19 Taskforce. A UK-based think tank working in nutrition education, research and innovation.
“However, a high-quality diet is important for assembling the right immune response, which can lead to sensitivity and severity to the infection,” said McAuliff, who was not involved in the study.
Other researchers in the study were from Brigham & Women Hospital in the United States, Cedars-Sinai Medical Center, Stamford Hospital, and Vagelos University of Physicians and Surgeons at Columbia University.