Reactive oxygen species
Research suggests chronic inflammation plays a major role in COVID-19 morbidity. In severe cases, COVID-19 causes a cytokine storm which contributes to excessive and uncontrolled inflammation of organs, particularly respiratory tissues. If untreated, this increased inflammation can result in reduced immune response, pneumonia, lymphoid tissue damage, and death. Individuals with abnormal cytokine production, such as those with obesity or systemic chronic inflammation, have a poorer health outcomes from COVID-19. Elevated cytokine production alters the innate immune response which leads to abnormal T-cell and B-Cell function that decreases control of viral replication and host defense. Anti-viral therapeutic drugs which also reduce inflammation seem to be the most effective treatment, but research is still ongoing. Reactive oxygen species are upregulated during inflammation as part of the immune response to defend against pathogens. However, excessive inflammation causes dangerous levels of reactive oxygen species which cause oxidative stress to tissues. The immune system naturally produces antioxidant compounds to regulate and detoxify reactive oxygen species. Anti-oxidative therapy with supplements such as Vitamin C, Vitamin E, Curcumin, or Baicalin is speculated to reduce infection severity in COVID-19, but previous research has not found antioxidants supplementation to be effective in the prevention of other diseases. Shifting from the typical western diet to a Mediterranean diet or plant-based diet may improve COVID-19 health outcomes by reducing prevalence of comorbidities (i.e. obesity or hypertension), decreasing intake of pro-inflammatory foods, and increasing consumption of anti-inflammatory and antioxidant nutrients.