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Exercise-induced immunodepression in endurance athletes and nutritional intervention with carbohydrate, protein and fat-what is possible, what is not?

Gunzer W, Konrad M, Pail E - Nutrients (2012)

Bottom Line: Heavily exercising endurance athletes experience extreme physiologic stress, which is associated with temporary immunodepression and higher risk of infection, particularly upper respiratory tract infections (URTI).Evidence of beneficial effects from other macronutrients is scarce and results are often inconsistent.Using a single nutrient may not be as effective as a mixture of several nutritional supplements.

View Article: PubMed Central - PubMed

Affiliation: Department of Dietetics and Nutrition, University of Applied Sciences FH JOANNEUM, Bad Gleichenberg, Austria. wolfgang.gunzer.dio09@fh-joanneum.at

ABSTRACT
Heavily exercising endurance athletes experience extreme physiologic stress, which is associated with temporary immunodepression and higher risk of infection, particularly upper respiratory tract infections (URTI). The aim of this review is to provide a critical up-to-date review of existing evidence on the immunomodulatory potential of selected macronutrients and to evaluate their efficacy. The results of 66 placebo-controlled and/or crossover trials were compared and analysed. Among macronutrients, the most effective approach to maintain immune function in athletes is to consume ≥6% carbohydrate during prolonged exercise. Because inadequate nutrition affects almost all aspects of the immune system, a well-balanced diet is also important. Evidence of beneficial effects from other macronutrients is scarce and results are often inconsistent. Using a single nutrient may not be as effective as a mixture of several nutritional supplements. Due to limited research evidence, with the exception of carbohydrate, no explicit recommendations to reduce post-exercise URTI symptoms with single macronutrients can be derived.

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Nutrient availability and immune function: direct and indirect mechanisms. It can be inferred that a poor nutrition state may exacerbate cellular immune responses to heavy exercise and further impair immune function [47]. Adapted with permission from Walsh [32] (Solid arrows: research evidence mostly supports link; dashed arrow: limited research evidence to support link in athletes; ↑: increase; ↓: decrease).
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nutrients-04-01187-f001: Nutrient availability and immune function: direct and indirect mechanisms. It can be inferred that a poor nutrition state may exacerbate cellular immune responses to heavy exercise and further impair immune function [47]. Adapted with permission from Walsh [32] (Solid arrows: research evidence mostly supports link; dashed arrow: limited research evidence to support link in athletes; ↑: increase; ↓: decrease).

Mentions: Scientific research has long shown that inadequate nutrition may contribute to impaired immunity and makes the individual more susceptible to infection (Figure 1) [32,40]. Energy-restricted diets are common in sports, where low body fat is desired, such as running and cycling [41], and could be accompanied by macro- and micronutrient deficiencies [2]. Excesses in specific nutrients, such as carbohydrates at expense of protein, training in a dehydrated state and excessive use of nutritional supplements may also lead to direct and indirect negative effects on the immune function in athletes and may be partly responsible for higher infection risk [1,32,42]. Maintaining the normal function of immune cells requires an adequate amount of water, glucose, proteins and electrolytes [43]. As a logical consequence, meeting nutritional demands helps to maintain an effective immune system [42].


Exercise-induced immunodepression in endurance athletes and nutritional intervention with carbohydrate, protein and fat-what is possible, what is not?

Gunzer W, Konrad M, Pail E - Nutrients (2012)

Nutrient availability and immune function: direct and indirect mechanisms. It can be inferred that a poor nutrition state may exacerbate cellular immune responses to heavy exercise and further impair immune function [47]. Adapted with permission from Walsh [32] (Solid arrows: research evidence mostly supports link; dashed arrow: limited research evidence to support link in athletes; ↑: increase; ↓: decrease).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3475230&req=5

nutrients-04-01187-f001: Nutrient availability and immune function: direct and indirect mechanisms. It can be inferred that a poor nutrition state may exacerbate cellular immune responses to heavy exercise and further impair immune function [47]. Adapted with permission from Walsh [32] (Solid arrows: research evidence mostly supports link; dashed arrow: limited research evidence to support link in athletes; ↑: increase; ↓: decrease).
Mentions: Scientific research has long shown that inadequate nutrition may contribute to impaired immunity and makes the individual more susceptible to infection (Figure 1) [32,40]. Energy-restricted diets are common in sports, where low body fat is desired, such as running and cycling [41], and could be accompanied by macro- and micronutrient deficiencies [2]. Excesses in specific nutrients, such as carbohydrates at expense of protein, training in a dehydrated state and excessive use of nutritional supplements may also lead to direct and indirect negative effects on the immune function in athletes and may be partly responsible for higher infection risk [1,32,42]. Maintaining the normal function of immune cells requires an adequate amount of water, glucose, proteins and electrolytes [43]. As a logical consequence, meeting nutritional demands helps to maintain an effective immune system [42].

Bottom Line: Heavily exercising endurance athletes experience extreme physiologic stress, which is associated with temporary immunodepression and higher risk of infection, particularly upper respiratory tract infections (URTI).Evidence of beneficial effects from other macronutrients is scarce and results are often inconsistent.Using a single nutrient may not be as effective as a mixture of several nutritional supplements.

View Article: PubMed Central - PubMed

Affiliation: Department of Dietetics and Nutrition, University of Applied Sciences FH JOANNEUM, Bad Gleichenberg, Austria. wolfgang.gunzer.dio09@fh-joanneum.at

ABSTRACT
Heavily exercising endurance athletes experience extreme physiologic stress, which is associated with temporary immunodepression and higher risk of infection, particularly upper respiratory tract infections (URTI). The aim of this review is to provide a critical up-to-date review of existing evidence on the immunomodulatory potential of selected macronutrients and to evaluate their efficacy. The results of 66 placebo-controlled and/or crossover trials were compared and analysed. Among macronutrients, the most effective approach to maintain immune function in athletes is to consume ≥6% carbohydrate during prolonged exercise. Because inadequate nutrition affects almost all aspects of the immune system, a well-balanced diet is also important. Evidence of beneficial effects from other macronutrients is scarce and results are often inconsistent. Using a single nutrient may not be as effective as a mixture of several nutritional supplements. Due to limited research evidence, with the exception of carbohydrate, no explicit recommendations to reduce post-exercise URTI symptoms with single macronutrients can be derived.

Show MeSH
Related in: MedlinePlus