Boosting immunity

Prior research has shown that regular, moderate exercise may help boost the immune system and reduce respiratory infections, but research has also shown that people who engage in regular, intense and prolonged exercise—such as athletes—may be at increased risk for respiratory infections.

In this study, researchers test the effects of pleuran, an insoluble form of beta-glucan from the mushroom Pleurotus ostreatus (commercial name Imunoglukan), which has previously been shown to have immune-boosting properties. Every day for three months, 50 randomly assigned athletes were given either two capsules of Immunoglukan (100 mg of beta-glucan and 100 mg of vitamin C) or placebo supplements (vitamin C 100 mg only) and were monitored for symptoms of upper respiratory tract infections for three months following supplementation.

Results showed that the athletes who took pleuran had increased levels of natural “killer” cells—cells in the immune system that help fight infection—and reduced upper-respiratory infection symptoms compared with the placebo group. The authors comment, “[Upper respiratory tract infection] symptoms at a crucial time in the athlete’s training or competition schedule can have adverse effects on performance. It has been suggested that immunonutrition for heavily exercising athletes is needed and helps maintain immunity and health.”

Staying in top shape

While such research holds promise, this is one small study, supported by the makers of Immunoglukan, so further research is needed to assess the safety and effectiveness of such supplements.

In the meantime, for athletes who need to be on top of their game in order to perform and win, here are a few tips for staying in optimal shape:

• Balance is key. Even athletes can overtrain and exercise too much, which increases the risks of injuries and physical and emotional stress. The healthiest athletes engage in a balanced life of training, sleeping, eating right, and enjoying a social life which includes “down” time.
• Eat right for optimal performance. While athletes may have special diets that they follow before performance and during training times, they still need a diet that includes an abundance of fruits and vegetables—providing essential nutrients—and a source of protein, as well as other foods including whole grains. Extreme dieting does not add to the health or performance of an athlete but rather increases the risk of injury and disease.
• Turn to healthy living to optimize performance. Some athletes turn to high-dose supplements or steroids to enhance performance, but this may come at a cost, particularly in the case of steroids, which can be dangerous. Athletes should engage in a healthy lifestyle with expert training advice from a balanced coach and talk with a knowledgeable doctor before taking supplements.

 (Eur J Appl Physiol DOI 10.1007/s00421-011-1837-z)