What are the best foods to consume when suffering from influenza?

Best Foods for Influenza

When suffering from influenza, the best foods to consume are hydrating fluids, clear broths like chicken soup, fruits and vegetables rich in vitamins C and D, lean proteins, and foods containing zinc and selenium to support immune function.

Nutritional Priorities During Influenza

Hydration

• Maintain adequate hydration with water, clear broths, and herbal teas
• Patients whose oxygen saturation is 92% or less should be treated with oxygen, but all patients should maintain fluid intake 1
• When children are unable to maintain oral intake, supplementary fluids should be given by the enteral route when possible 1

Immune-Supporting Foods

Vitamins and Minerals

• Vitamin C-rich foods: citrus fruits, strawberries, bell peppers
• Vitamin D sources: fatty fish, egg yolks, fortified foods
• Zinc-containing foods: lean meats, poultry, seafood, nuts, seeds
  • Taking 75 mg/day of zinc supplements (lozenges) when symptoms of a cold begin can reduce the duration of symptoms 1
• Selenium sources: Brazil nuts, seafood, whole grains

Protein Sources

• Protein intakes of at least 1.2 g/kg body weight/day are required for optimal immune function 1
• Some evidence suggests that higher protein intakes (up to 3 g/kg body weight/day) may reduce respiratory infection incidence during periods of intense physical stress 1
• Lean meats, poultry, fish, eggs, and plant-based proteins like legumes are recommended

Anti-Inflammatory Foods

• Chicken soup has been shown to inhibit neutrophil chemotaxis in vitro, suggesting mild anti-inflammatory effects that may help mitigate symptoms of upper respiratory tract infections 2
• Fresh fruits and vegetables (at least five portions daily) are associated with reduced infection risk 1
• Foods containing polyphenols (green tea, berries) may help reduce respiratory infection risk 1

Dietary Pattern Recommendations

During Acute Illness

1. Focus on hydration:

   • Water, clear broths, herbal teas
   • Warm liquids can help soothe throat irritation and thin mucus

2. Small, frequent meals rather than large meals:

   • Easier to digest when appetite is poor
   • Helps maintain energy levels
   • Eating 4-6 small meals throughout the day rather than 3 large meals is recommended for recovery 3

3. Nutrient-dense foods:

   • DASH eating plan provides a good framework with emphasis on:
     • Fruits: 4-5 servings daily
     • Vegetables: 4-5 servings daily
     • Whole grains: 6-8 servings daily
     • Lean proteins: 6 oz daily 1

Foods to Limit or Avoid

• Alcohol should be limited to no more than 2 units per day, with avoidance of binge drinking, as it negatively impacts immune cell function 1
• Ultra-processed foods and those high in added sugars should be minimized 3
• Carbonated beverages may irritate the throat and should be limited 3

Special Considerations

For Children

• Children can be safely discharged from hospital when they:
  • Are clearly improving
  • Are physiologically stable
  • Can tolerate oral feeds
  • Have a respiratory rate <40/min (<50/min in infants)
  • Have an awake oxygen saturation of >92% in air 1

For Those with Malnutrition

• Subjects with malnutrition should optimize their nutritional status through diet counseling from experienced professionals 1
• Malnutrition is a significant predictor of mortality in influenza infection 1
• Retrospective analysis of the 1918 influenza pandemic revealed that malnutrition and famine were associated with high disease severity and mortality 1

Supplement Considerations

• A broad-range multivitamin/mineral supplement may be beneficial when food intake is limited 1
• Vitamin D3 supplementation (2000 IU/day) may benefit those who are deficient or insufficient, especially during winter months 1
• Daily probiotic ingestion (particularly Lactobacillus and Bifidobacterium species) may result in fewer days of respiratory illness and lower severity of symptoms 1

Evidence-Based Approach

• Natural nutrients contained in whole foods (vitamin C, iron, selenium, omega-3 fatty acids) have been shown to positively affect immunity, evidenced by lower incidences and milder courses of infection 4
• Vitamin D3 supplementation has been correlated to sporadic incidence of viral infections 4
• Consuming a variety of nutrients through whole foods appears more beneficial than relying solely on supplements 4, 5

By following these dietary recommendations during influenza illness, patients can support their immune function, maintain hydration, and potentially reduce the duration and severity of symptoms.