Covid-19 and Vegan/Vegetarian Diets

By Reed Mangels, PhD, RD

As of June 1, 2024, according to the CDC, nearly 1.2 million people have died of COVID-19 in the United States. Worldwide, the World Health Organization reports that 7.1 million people have died of Covid-19. The CDC reports that, In the United States, 5.3% of adults are currently experiencing post-COVID conditions (long COVID). These adults had COVID, had long-term symptoms, and are still experiencing symptoms.

In December 2022, I responded to a question about Covid-19, namely, “Does being vegan affect my risk of getting Covid-19 or severe Covid-19?” At that time, no studies had been published investigating the association between a vegan diet and Covid-19 risk. Studies that looked at healthy diets or eating more plant foods found that:

• Higher healthful plant-based diet scores (more fruits and vegetables) were associated with lower risk of Covid-19 and severe Covid-19. (1).
• Health care workers had a lower risk of having moderate-to-severe Covid-19 if their diets were more “plant-based” (more vegetables, legumes and nuts; less poultry and red/processed meat) (2).
• Higher “healthy eating” scores (more vegetables, fruits, whole grains, legumes, and nuts and less red/processed meat) were associated with a lower risk of Covid-19 and of severe infection (3).
• Eating more vegetables, fruits, legumes, nuts, whole grains, and fish in the year prior to a Covid-19 diagnosis was associated with significantly less severe Covid-19 and a shorter duration of hospitalization (4).

Since then, a couple of studies have been published that include vegetarian subjects. There still have not been published studies looking exclusively at vegans. Here’s what the newer studies found:

• In Taiwan, in a study of 509 people who had been diagnosed with Covid-19, study subjects age 65 years and older who reported that they followed a vegetarian diet, were likely to have less severe symptoms than similarly aged subjects who were not vegetarian (5).
• In Brazil, study subjects were divided into 2 groups – omnivores (424 people) and plant-based (278 people). The plant-based group included people consuming meat 3 or fewer times per week, lacto-ovo vegetarians, and vegans. The plant-based group were less likely to get Covid-19; the nonvegetarian group had a higher rate of moderate-severe Covid-19 compared to the plant-based group (6). This study’s researchers reported that the results seen in the plant-based group were mainly due to the vegetarian + vegan subgroup. The group differences persisted even after adjustments were made for BMI, suggesting that other factors in the plant-based diet were responsible for the lower risk of Covid-19 and moderate-severe Covid-19.

The results of these studies suggest that in addition to other health benefits, vegetarian/vegan/plant-based diets could reduce risk and severity of Covid-19. This information could be useful in case of new outbreaks of Covid-19 in the future.

References

1. Merino J, Joshi AD, Nguyen LH, et al. Diet quality and risk and severity of COVID-19: a prospective cohort study. Gut. 2021;70:2096-2104.
2. Kim H, Rebholz CM, Hegde S, et al. Plant-based diets, pescatarian diets and COVID-19 severity: a population-based case-control study in six countries. BMJ Nutr Prev Health. 2021;4:257-266.
3. Yue Y, Ma W, Accorsi EK, et al. Long-term diet and risk of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and Coronavirus Disease 2019 (COVID-19) severity. Am J Clin Nutr. 2022;116:1672-1681.
4. Zargarzadeh N, Tadbir Vajargah K, Ebrahimzadeh A, et al. Higher adherence to the Mediterranean dietary pattern is inversely associated with severity of COVID-19 and related symptoms: A cross-sectional study. Front Med (Lausanne). 2022;9:911273.
5. Hou YC, Su WL, Chao YC. COVID-19 illness severity in the elderly in relation to vegetarian and non-vegetarian diets: A single-center experience. Front Nutr. 2022;9:837458.
6. Acosta-Navarro JC, Dias LF, de Gouveia LAG, et al. Vegetarian and plant-based diets associated with lower incidence of COVID-19. BMJ Nutr Prev Health. 2024;7:4-13.

You can read the earlier article I wrote about diet and Covid-19 here.