Healthier diet may protect from severe COVID-19

There's good news and bad news.

The good news is that now we have some information on the way diet may affect the severity of COVID-19, the illness caused by the SARS-CoV-2 virus. The bad news is that we've been in a pandemic long enough that such research can be carried out (BMJ 2021;4:e000272).

Between July 17 and September 25 of 2020, America-based researchers surveyed via website over 2,800 healthcare workers in six countries (France, Germany, Italy, Spain, the UK and the United States) who were working in capacities and specialties that put them at high risk of contracting the virus.

Through their web-based interview software, the authors compiled information regarding the participants' demographics, medications, general lifestyle, dietary history, and whether they had experienced symptoms of COVID - and if so, the symptoms' severity.

For dietary history, the authors asked the participants if they followed any particular diet for the year before COVID, presenting such options as whole foods, plant-based; vegetarian diet; Mediterranean diet; keto; paleo; pescatarian (vegetarian that allows fish and shellfish); low-carb/high-protein diet; other; and none of the above.

In addition to selecting their own preferred diet, the participants provided details of what they usually ate to help the authors confirm their choice.

The researchers noted that the participants' diets could fall into one of three categories: "plant-based diets", "plant-based diets or pescatarian diets" and "low carbohydrate, high protein diets" and performed their analysis of the participants' diets comparing the risk of contracting moderate-to-severe COVID with the risk of contracting mild-to-moderate COVID.

After taking into account Body Mass Index, access to PPE (Personal Protective Equipment), dietary supplement use, medical specialty, health behaviors, and other variables, the authors found that "Compared with those who followed plant-based diets [including pescatarian diets], those who followed low carbohydrate, high protein diets had >3-fold higher odds of moderate-to-severe COVID-19."

The biggest difference between the "plant-based/pescatarian" diets and the "low-carb, high-protein" diets? The consumption of land animal protein, most notably red meat and processed meats.

Let me repeat that: those on a low-carb diet (including keto, paleo, and high-protein diets) were three times more likely to have moderate-to-severe COVID than those who avoided land animal protein.

What this means for you

This is a particularly interesting study because the participants are all so highly educated: over 95% of participants were physicians, so they are likely to be able to describe their usual diet with some degree of accuracy as well as their COVID symptoms.

This does not tell us WHY those who followed a more plant-based diet seemed to have less serious COVID symptoms, but the authors took into account as many variables as they could, including health history and medication or supplement use. It does, however, highlight the ways that a diet high in vegetables, fruits, legumes, and whole grains can buttress your health, even in response to such serious attacks as COVID.

A last note: these healthcare workers were not vaccinated when this study was performed, and their access to timely testing may have been limited.

The vaccines for COVID have been shown to be overwhelmingly safe and effective: if you have not yet been vaccinated, please speak with your physician about getting the vaccine as soon as it is safe for you to do so.

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