A vegan or plant-based diet cannot prevent a person from developing COVID-19, but it may help support a healthy immune system. This in turn could aid in SARS-CoV-2 infection prevention and lower the risk of severe symptoms.

People should note, that there is no direct evidence to support a link between a plant-based or vegan diet and protection from COVID-19 or other severe diseases.

That said, plant-based diets can also decrease a person’s risk of obesity and chronic diseases. These are conditions that tend to worsen the outcome of COVID-19.

This article explores plant-based diets and their health benefits in relation to COVID-19 and otherwise. It also looks at how a vegan diet could decrease the risk factors for more severe effects of COVID-19.

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There is no specific diet that lowers a person’s risk of developing COVID-19.

The World Health Organization (WHO) advise people eat a balanced diet to strengthen their immune systems during the COVID-19 pandemic. This includes eating fresh, unprocessed foods, such as vegetables, legumes, and whole grains.

The WHO also recommend avoiding consumption of sugar fat, and salt, and limiting red meat consumption to 1–2 times a week, and poultry to 2–3 times per week. They also suggest consuming no more than 160g of meat and beans daily.

According to research, a plant-based diet has health benefits for weight, energy metabolism, and systemic inflammation. These beneficial effects could support a healthy immune system and lower a person’s risk of severe impacts of COVID-19.

That said, it is important to note that eating a plant-based diet and identifying as a vegan are not, strictly speaking, the same. The term “plant-based” refers only to diet, while veganism incorporates other factors.

People who identify as vegans object to exploiting or killing animals for food, clothing, or any other reason. However, some people who identify as vegans may eat mainly processed foods, which in itself as a dietary plan is not beneficial to health.

By contrast, people who follow a plant-based diet eat mainly or exclusively plant foods. People may have a diet that consists solely or predominantly of freshly prepared whole foods. They may choose this approach for health, environmental, or ethical reasons.

It is of note that a plant-based diet does not necessarily lead to an improved immune system. A person can follow a plant-based diet and have poor health due to consuming far too many processed foods, plant-based alternatives, and plant fats.

If a person eats mainly processed foods and few vegetables and fruits and does not supplement essential nutrients, such as vitamin B12, they may counteract the potential benefits of a plant-based diet.

Learn more about foods with B12 for vegetarians and vegans here.

In the sections below, we discuss some of the health benefits of plant-based diets and how following them may impact the risk of developing COVID-19.

More vitamins and minerals

A review in the British Journal of Nutrition suggests that people with optimal levels of micronutrients may be more resilient to COVID-19.

Micronutrients are vitamins and minerals that people obtain from their diet. Human bodies also produce vitamin D in response to exposure to sunlight.

Plant foods contain many vitamins and minerals essential for a healthy immune system, such as zinc, selenium, and vitamins A, C, and E. Selenium is a trace mineral that benefits immune system health and cognitive function.

However, according to the Centers for Disease Control and Prevention (CDC), only one in 10 adults in the United States eat enough fruits or vegetables.

By switching to a plant-based diet that includes a wide variety of fruits and vegetables or eating more plant-based foods, people will increase their intake of essential minerals and vitamins that support the immune system. This in turn may increase people’s resilience to COVID-19.

Learn more about anti-inflammatory foods here.

Increased antioxidants and polyphenols

Healthy vegan diets that include a wide variety of fruits and vegetables are rich in antioxidants. These are compounds that fight free radicals and help counteract oxidative stress.

Some vitamins and minerals, as well as plant compounds such as polyphenols, act as antioxidants. Polyphenols are present in berries, olives, and nuts, among other foods.

According to a 2021 review, studies are currently underway to test whether polyphenols could potentially help prevent or treat viral infections, such as infections with SARS-CoV-2. However, at present, there is no evidence of this.

The authors explain that as people age, their immune system is less able to combat infections. The researchers refer to this immunological aging as immunosenescence. Polyphenols can counteract the senescence process and reduce inflammation.

Another review notes that excessive oxidative stress may be responsible for the lung damage, thrombosis, and red blood cell dysregulation that occurs in some people with COVID-19.

The authors of the review suggest that antioxidants could have therapeutic effects. Therefore, a plant-based diet rich in antioxidants and polyphenols may help protect against COVID-19.

Learn more about some of the top foods high in antioxidants here.

Support for a healthy gut microbiome

According to some research, SARS-CoV-2 alters the gut microbiota, and probiotics and prebiotics may improve the immune function in people with a SARS-CoV-2 infection.

The fiber in plant foods provides prebiotics to feed gut bacteria. Research shows that plant-based diets influence the gut microbiome favorably, increasing bacterial diversity and potentially reducing inflammation.

According to a 2020 review, a plant-based fiber-rich diet may have protected COVID-19 patients in India. The authors suggest that plant-based foods are likely to boost a gut microbiota capable of triggering an anti-inflammatory response.

Decreased obesity and comorbidities

Eating a plant-based diet may help people avoid having obesity and other health conditions that could worsen their experience of COVID-19 if they develop it.

Research suggests that a SARS-CoV-2 infection results in increased hospitalization rates and greater severity of illness in people with diabetes or obesity.

According to a 2020 study, obesity was the most commonly reported underlying medical condition — 72.5% — in healthcare personnel hospitalized for COVID-19 in the United States.

Authors of a 2016 analysis indicate that plant-based diets could decrease inflammation and risk of chronic disease in people who have obesity.

A 2019 review notes a plant-based diet may help prevent the development of overweight, obesity, and diabetes. Research also supports the diet’s cardiovascular benefits.

According to a large 2018 study, there is a link between healthy plant-based diet and a lower risk of all-cause mortality in adults in the U.S.

Moreover, other studies indicate that people who eat plant-based diets may have a lower risk of breast cancer, hypertension, and rheumatoid arthritis symptoms.

Evidence also suggests that plant-based diets adequately support a person’s exercise and athletic performance.

Learn more about the benefits of a vegan diet here.

People wishing to switch to a vegan diet should ensure that they eat fresh whole foods and avoid processed foods and “vegan junk food.”

With veganism gaining popularity, more and more grocery stores and food outlets now offer a variety of vegan products.

It is important to note, however, that that a product is vegan does not necessarily mean it is healthy. It is still advisable to check nutrient density and the amounts of vitamins, minerals, fats, and added sugars of vegan products people consider buying.

People will benefit most from choosing fruits and vegetables, whole grains, and healthy fats and protein sources.

Including a wide variety of plant foods and “eating a rainbow” allows people on a plant-based diet to get all the nutrients they need.

However, plant foods do not contain vitamin B12, an essential nutrient needed for red blood cell production and brain function, among other things.

That is why it is important for people on a plant-based diet to eat foods fortified with vitamin B12 and preferably take a vitamin B12 supplement. They may also need to supplement omega-3 fatty acids.

People can find numerous resources and recipes online to plan their plant-based meals. They may also consult a registered dietitian or nutritionist.

Learn more about plant foods high in protein here.

There is no conclusive evidence to suggest that any single diet can lower a person’s risk of developing COVID-19.

However, a plant-based or vegan diet may support a healthy immune system. This in turn can limit the risk of a SARS-CoV-2 infection, as well as its serious health complications.

Eating a plant-based diet may also help prevent the development of chronic health conditions that might cause complications or increase the severity of COVID-19 symptoms.

A vegan diet may also help people reach a moderate weight and prevent obesity, reducing the risk of worse COVID-19 outcomes.

It is worth noting that not all vegan foods are healthy, and people should avoid processed vegan foods and choose a whole foods diet instead.

People following a strict vegan diet should also ensure that they supplement essential nutrients, such as vitamin B12.