Nutrition to Support Immune Function

Reducing the risk of upper respiratory infection (URI)

Many studies over the last 35 years report an increase in upper respiratory infection (URI) symptoms in athletes during periods of heavy training and competition. Many challenges athletes face such as heavy exercise and life stress can influence immune function leading to missed/impaired training sessions or competition having both negative consequences on both athlete wellbeing and performance.

Recent studies have identified prominent risk factors, including intensified training in the winter; long-haul travel; low energy availability; high levels of psychological stress and anxiety; and depression.

Nutrition to maintain immune health

To enhance athlete wellbeing and a large amount of research has focused on nutritional strategies to improve immune function at rest and in response to intense training and travel. Although there is some convincing evidence that meeting requirements of sufficient intakes in carbohydrate and protein and avoiding deficiencies in nutrients such as vitamin D and antioxidants is integral for optimal immune health, well-powered randomised controlled trials reporting improvements in URS beyond such intakes are lacking. As practitioners, we first need to understand whether nutritional practices increase the risk of illness. Second, with some promising evidence support of efficacy and mechanisms of immune-enhancing nutritional supplements (e.g. probiotics) on URS it may be beneficial to implement strategies with illness prone athletes and during periods of high stress (e.g. competition and travel) whilst more research is being conducted in randomised controlled trials in elite athletes.

The latest Nutrition recommendations to maintain immune health

  • Eat a well-balanced diet
  • Ensure adequate protein intake (1.2-1.7g/kg/BM/day)
  • At the onset of a cold consider zinc lozenges (75mg per day)
  • Consider probiotic use for illness prone/travelling
  • Consider vitamin D supplementation from autumn- spring (screen first)
  • Consider Vit C for illness prone and during competition (200mg per day)

(Neil Walsh, 2019)