Expert Advice| 权威建议

Building a Healthy Immune System

February 17, 2014 4:32 pm | By Linda Yung


Now that it is winter, the weather is chillier, and everyone around you is getting sick. But it doesn’t have to be that way! By eating the right foods and performing the appropriate amount of exercise, you can make sure your immune system is functioning at full capacity to keep you healthy.

One way to prevent getting a cold or the flu this semester is to make sure your diet is packed with antioxidants. Antioxidants are vitamins, minerals, and other nutrients that protect and repair cells from damage caused by free radicals. Free radicals are toxic by-products produced by our bodies when we process the food we eat into energy. They are also byproducts of cigarette smoke, pollution, sunlight exposure, and other environmental factors that can suppress the immune system. In the long term, this damage is associated with chronic diseases such as hardening of atherosclerosis, cancer, and arthritis.

So, what’s on the menu? In terms of vitamins, A, C, and E all have antioxidant properties.

Food Sources
Vitamin A Regulates the immune system and protects the body from infections by keeping the tissue lining of your mouth, stomach, intestines and respiratory system health sweet potato, pumpkin, kale, spinach, carrots, squash
Vitamin C Protects your body from infections by stimulating the formation of antibodies cranberries, cauliflower, and beets, or citrus fruits like oranges, lemon, and grapefruit
Vitamin E Neutralizes the activity of free radicals and can help prevent long-term chronic illnesses walnuts, almonds, peanut butter, and vegetable oils


In addition to vitamins, also consider foods that are rich in polyphenols and flavonoids which prevent cells, namely blood vessels, from oxidative damage. This winter try eating more apples, pears, garlic, and red grapes, as well as drinking more hot tea. 

Exercising regularly can also boost your immune system. Exercise sends antibodies and white blood cells at an increased rate through the body. This allows the antibodies and white blood cells to detect potential illnesses earlier. The increased rate of circulation may also release hormones that alert immune cells of intruding bacteria or viruses. Furthermore, studies have found that exercise decreases the release of stress-related hormones, which is linked to illness. 

For those who are still trying to work exercise into their schedules, the intensity and duration of exercise to support the immune system is less than that needed for cardiovascular training. Therefore even moderate levels of aerobic exercise are adequate to provide protection for your immune system. Twenty to 30 minutes of brisk walking five days per week, going to the gym every other day, or bicycling a few times a week are feasible training program for maintaining a healthy immune response.

Though exercising is a great way to keep the immune system healthy, be careful not to over exert yourself. Vigorous long-term exercise such as marathon training or intense gym regimens could actually decrease the amount of white blood cells circulating through the body and increase the presence of stress-related hormones. 

So, what do you have to do to make sure you and your friends all stay healthy this winter? Just remember to eat a variety of fruits and vegetables and to always put aside some time for exercise. 


Linda Y. Yung is a die-hard New Yorker working towards a career in dietetics with lofty goals of changing the American diet. She is a proud double Jumbo at Tufts University, having received her Bachelor of Arts in International Relations and Biomedical Sciences and her Master of Science in Food Policy and Applied Nutrition. Linda can also be described as any of the following: aspiring jet-setter, amateur tai chi master, or a hopelessly addicted NBA junkie. In her free time, she enjoys meandering through foreign markets, reading science fiction, and experimenting in the kitchen. She can be reached at or