While washing hands with soap and sanitizers is one way to ward off cold and flu germs this winter, eating properly to strengthen the immune system will help fight the germs that manage to pass the hygiene barrier.

Christina Schmidt, nutritionist and author of “The Toddler Bistro: Child-Approved Recipes and Expert Nutrition Advice for the Toddler Years,” says a good way to boost the immune system is through the diet.

“A healthy immune system is a powerful line of defense from those nasty viruses,” Schmidt said.

Several nutrients and food components act as antioxidants to keep the immune system strong and functioning properly. The nutrients can reduce inflammation, compete with infectious bacteria and activate white blood cells, which fight infection.

The following nutrients and foods are recommended to boost the immune system:

•Vitamin C: citrus fruits, berries, kiwis, peppers, tomatoes.

•Vitamin E: wheat germ, nuts, fortified cereals, sweet potatoes.

•Beta carotene provitamin A: yellow and dark green leafy vegetables, sweet potatoes, orange squash, apricots, cantaloupe.

•Zinc: meats, fish, poultry, fortified cereals, milk.

•Iron: meats, poultry, fish, egg yolk, dried fruits, fortified grains, dark molasses.

•Copper: meats, nuts, chocolate, cherries, whole grains.

•Selenium: grains, meats, onions, milk.

•Folic acid: green leafy vegetables, eggs, meats, fish, beans, broccoli.

•Vitamin B6: wheat germ, milk, egg yolks, meats.

•Vitamin B12: milk, eggs, meats.

•Omega-3 fats: cold-water fish, flax oil, soybeans, walnuts, dark green leafy vegetables.

•Probiotics: yogurts with the “Live and Active Cultures” seal, fortified foods, supplements.

•Garlic: on its own or in sauces, soups, ready-to-eat meals, supplements. Schmidt says some of her favorite flu fighting dishes are wholewheat or enriched spaghetti with tomato vegetable marinara mixed with chopped chicken or ground turkey; lemony chicken, vegetable and rice soup; sweet potato or butternut squash soup; and whole-grain toast with a poached or scrambled egg.

“We are coming into cranberry season—a berry rich in antioxidants—so be sure to take advantage of fresh cranberry relishes and baked goods as well,” Schmidt said.

Some foods to be avoided are those that are high in refined sugars and saturated fats, which create energy peaks and valleys and weaken the immune system.