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UPMC Expert

Leslie Bonci, R.D., M.P.H.


UPMC Sports Nutritionist Says Good Diet, Moderate Exercise And Enough Rest Can Boost Immune System During Flu And Cold Season

People who exercise strenuously may be more at risk for becoming rundown

PITTSBURGH, December 9, 2004 The flu vaccine is in dire supply this winter, but for young healthy people, there are ways to help boost the immune system through consistently proper nutrition, moderate exercise and plenty of rest, according to Leslie Bonci, R.D., M.P.H., director of sports nutrition at the University of Pittsburgh Medical Center (UPMC) Center for Sports Medicine.

Nutritional deficiencies, too much strenuous exercise and not enough sleep all can contribute to a weakened immune system and vulnerability to a cold or flu virus even in a very healthy, active person, said Bonci. Following are Bonci's 10 tips for healthy people to help maintain a strong immune system:

1) Instead of just focusing on vitamin C, enjoy a medley of healthy foods and beverages, including plenty of plant-based foods with smaller amounts of lean animal products (fish, poultry, lean beef) and dairy selections. The phytonutrients in plant-based foods may actually boost immunity.

2) Drink warm black tea. Many people drink tea only when they are sick, but certain components in tea may help maintain healthy immune function when you're not sick.

3) Keep up your natural defenses with yogurt and other probiotics that contain live and active cultures, which may help ward off infections by improving the balance of bacteria in the gastrointestinal tract. A popular myth that dairy foods cause mucus is wrong.

4) Enjoy citrus and other vitamin C-rich foods such as peppers, broccoli, tomatoes and potatoes. Vitamin C, a potent antioxidant, may help decrease the duration and severity of a cold. Try 1,000 milligrams of vitamin C at the beginning of the onset of a cold.

5) Eat selenium-rich foods, including nuts, oysters and clams, whole grains, pork, beef and lamb. Selenium is an antioxidant and mineral that plays a supporting role for the immune system and in controlling inflammation.

6) Eat zinc-containing foods, such as oysters, beef, seafood, poultry, nuts, seeds and whole grains. Zinc is a mineral necessary for a healthy immune system. Zinc, taken at the onset of a cold, may decrease the duration and severity of illness.

7) Be sure to get plenty of vitamin E, an immune-boosting antioxidant whose nutrients are rich in vegetable oils, seeds and nuts. Keep in mind that taking vitamin E supplements without adequate fat intake may prevent the body from absorbing the vitamin.

8) Don't overdo it physically. Daily moderate physical cardiovascular activity has been linked to a stronger immune system. However, very strenuous exercise, such as training for a marathon, has been shown to make the body more vulnerable to colds and flu.

9) Be sure you are getting enough sleep consistently. Lack of sleep can cause a cascade of hormonal responses that can actually promote weight gain, increase stress hormones and decrease immune function.

10) Wash hands frequently with soap and water wherever you are, including before and after using exercise equipment at the gym. While working out, try to keep your hands away from your mouth, nose and eyes because bacteria and viruses can easily multiply in warm, moist areas. Use your own clean towel to wipe away perspiration.

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