Food Fighters

Many fruits and vegetables boost your immune system. Try to incorporate at least seven servings a day into your diet. “Stock up on whole fruits, garlic, broccoli and green leafy vegetables,” Dr. Sujansky says. “Dark berries such as blueberries are especially potent antioxidant powerhouses.” Antioxidants help stabilize free radicals, which can damage the body’s cells and compromise your immunity.

Vitamin C also strengthens immunity and stimulates the formation of antibodies, the cells that help you fight illness. Although vitamin C can’t prevent colds, it may help shorten your cold and make the symptoms milder. Add citrus such as oranges and tangerines to your meals. Other vitamin C-rich foods include papayas, strawberries, tomatoes and red bell peppers. Get creative; put them in salads or enjoy as them as a snack.

Examine Supplements

To boost immunity, “supplements are such an attractive idea,” Dr. Sujansky says. “It’s so much easier to pop a vitamin tablet than to eat a healthy diet and exercise.”

Studies continue to debate the effectiveness of supplements. A review suggests that while getting vitamin C from foods helps the immune system and reduces infection risk, taking vitamin C supplements doesn’t yield those benefits.

However, the National Institutes of Health recently confirmed the benefits of taking vitamin D supplements because most people don’t get enough of it from food and sunlight. One study found that vitamin D supplementation yielded a 22% decrease in autoimmune disease such as rheumatoid arthritis and psoriasis.

Supplements don’t precisely mimic the nutrients in whole fruits and vegetables. Your best bet: Eat a balanced diet for the best immune system-boosting nutrients, and work with a nutritionist if you suspect any deficiencies in your diet that might benefit from supplementation.

A Fortified Immune System Benefits Your Health

“Believe it or not, you can also boost your immune system by taking some quality time for yourself,” Dr. Sujansky says. “Visit with friends or spend time alone in quiet contemplation and meditation.”

Also, don’t forget to exercise and get enough rest. “Eating right, exercising, getting enough sleep — these are scientifically proven to reduce inflammatory markers and improve antibodies and the way that they function,” Dr. Sujansky says. “These common-sense actions can help you dodge winter illnesses.”