How could diet affect the flu?

Much like the common cold, diet is connected to the flu through immunity. Diets that are sufficient in energy, micronutrients, and macronutrients are important for maintaining a robust immune system, which will help reduce the risk and severity of common flu infections.^[1] Flavonoids (plant compounds that have antioxidant and immunomodulatory properties; found in especially high quantities in tea, chocolate, capers, and oregano)^[2] may be a noteworthy nutrient for this purpose.^[3]