[Influence of diet in COVID-19 infection and severity risk: a systematic review]. / Influencia de la dieta en el riesgo de infección y de gravedad de la COVID-19: una revisión sistemática.

Introduction: Introduction: the risk and/or prognosis of COVID-19, caused by the SARS-CoV-2 virus, have been related to chronic diseases such as obesity, diabetes mellitus, and cardiovascular diseases, with poor-quality diet being a predisposing factor for these diseases. Objective: to synthesize the scientific evidence on the effect of diet on the risk of SARS-CoV-2 infection and severe COVID-19. Methods: a systematic review was carried out following the PRISMA guidelines. The bibliographic search was made in the databases Web of Science, Scopus and Medline (through the PubMed search engine). Risk of bias analysis was performed using the Newcastle-Ottawa and Joanna Briggs Institute Critical Appraisal Checklist for Analytical Cross-Sectional Studies scales. Results: 14 studies were included. Good adherence to the Mediterranean diet was associated with a decreased risk of SARS-CoV-2 infection (OR = 0.44; 95 % CI, 0.22-0.88, for high versus low adherence, and significant ORs of 0.88 and 0.95 in studies that analyzed adherence quantitatively) but not with the severity of COVID-19. A plant-based diet also had a protective association against both COVID-19 infection and severity. Specifically, a high consumption of vegetables, legumes and cereals, and a low intake of dairy products and red meat showed a protective effect against infection and/or COVID-19 severity, depending on the study. Vitamin and probiotic supplements also lowered the risk of infection. Conclusion: the available evidence suggests that a healthy diet, based on a Mediterranean or plant-based diet, with moderate consumption of dairy and red meat, exerts a protective effect against COVID-19.

Introducción: Introducción: el riesgo y/o el pronóstico de la COVID-19, causado por el virus SARS-CoV-2, se han relacionado con enfermedades crónicas como obesidad, diabetes mellitus y enfermedades cardiovasculares, siendo la dieta de mala calidad un factor predisponente para estas enfermedades. Objetivo: sintetizar la evidencia científica sobre el efecto de la dieta en el riesgo de infección por SARS-CoV-2 y de COVID-19 grave. Métodos: revisión sistemática realizada siguiendo las guías PRISMA. La búsqueda bibliográfica se hizo en las bases de datos Web of Science, Scopus y Medline (a través del buscador PubMed). El análisis del riesgo de sesgo se realizó mediante las escalas Newcastle-Ottawa y Joanna Briggs Institute Critical Appraisal Checklist for Analytical Cross-Sectional Studies. Resultados: se incluyeron 14 estudios. Una buena adherencia a la dieta mediterránea se asoció con una disminución del riesgo de infección por SARS-CoV-2 (razón de momios RM = 0,44; IC 95 %: 0,22-0,88, para adherencia alta versus baja, y RM significativas de 0,88 y 0,95 en los estudios que analizaron la adherencia de forma cuantitativa) pero no con la gravedad de la COVID-19. Una dieta basada en plantas presentó una asociación protectora frente a la infección y la enfermedad grave. Concretamente, un alto consumo de verdura, legumbres y cereales, y una baja ingesta de lácteos y carnes rojas mostraron un efecto protector frente a la infección y/o la COVID-19 grave, según el estudio. Los suplementos vitamínicos y probióticos también disminuyeron el riesgo de infección. Conclusión: la evidencia disponible sugiere que una dieta saludable, basada en un patrón de dieta mediterránea o en alimentos vegetales, con consumo de lácteos y carnes rojas moderado, ejerce un efecto protector frente a la COVID-19.

[Immunosenescence, viral infections and nutrition: A narrative review of scientific available evidence]. / Inmunosenescencia, infecciones virales y nutrición: revisión narrativa de la evidencia científica disponible.

Aging of the immune system, or immunosenescence, alters the viral immune response in the elderly, especially when frailty exists. Research findings have demonstrated an imbalance in pro- and anti-inflammatory mechanisms, reduced production and diversification of T lymphocytes, and an alteration in immunovigilance and antibody synthesis. In this context, nutrition has a role in combating sarcopenia and frailty. Some food components that contribute to immune-competence are protein, vitamin D, n-3 fatty acids, antioxidant vitamins (vitamins C and E), zinc, selenium and iron. In times of a pandemic, nutritional recommendations for immune-competence in the elderly should be based on clinical studies. In this article, immunosenescence and its relationship to nutrition are addressed, including interventions studied in the context of the COVID-19 pandemic.