The saying goes that you are what you eat, so it makes sense that eating healthy foods can help you stay healthy.
“You can’t underestimate the importance of good nutrition when it comes to…your immune system,” says Karen Ansel, RD, a spokesperson for the Academy of Nutrition and Dietetics. “Vitamins, minerals, antioxidants—these are what keeps your body strong, and without them you’re not giving your body the edge it needs to ward off infection.”
And am not talking just fruits and vegetables: Foods from every food group are represented here. Make them a part of your diet for your best defense against colds and flu.
Oily fish—including salmon, tuna, and mackerel—are rich in omega-3 fatty acids, compounds that help reduce harmful inflammation in the body. Chronic inflammation prevents your immune system from working properly, and can contribute to colds and flu as well as more serious diseases.
Omega 3s may fight colds on more than one front. In a placebo-controlled 2011 study published in Brain, Behavior and Immunity, medical students who took fish oil supplements for three months had lower inflammation levels and also fewer symptoms of anxiety—a condition that can itself weaken immune function.
These pungent cloves do more than just flavor your food. Garlic also contains allicin, a sulfuric compound that produces potent antioxidants when it decomposes.
A 2001 study in the journal Advances in Therapy found that people who took garlic supplements for 12 weeks between November and February got fewer colds than those who took a placebo. And of those who did get sick, those who took the garlic supplement felt better faster.
Garlic packs the biggest antioxidant punch when eaten raw. Flavor too strong for you? Consider taking aged-garlic extract capsules.
Recent research suggests that vitamin C may not be as useful in preventing colds as once thought. However, studies do show that taking the vitamin at the first sign of illness may reduce a cold’s duration by about a day, which can feel like a lifetime when you’re suffering.
Eating lots of citrus—whether that entails digging in to orange and grapefruit slices, or using lemons and limes in recipes—will provide plenty of this powerhouse nutrient. Don’t worry about overdoing it, since it’s very hard to overdose on vitamin C. Anything your body doesn’t use is just washed right out of your system.
Like citrus fruits, red peppers are high in vitamin C. In fact, one red pepper has 150 milligrams of the nutrient—that’s twice the recommended daily allowance for women. (A large orange, by comparison, only has about 100 milligrams.)
Even that may not be enough, however, as studies suggest you need much more than that to harness the nutrient’s cold-fighting benefits. “If you’re sick, you should be eating a lot of vitamin C throughout the day—400 to 500 milligrams,” Ansel says.
Much of the vitamin D that our bodies need to build strong bones, defend against heart disease, and—you guessed it—bolster our immune system is produced when the sun’s rays interact with our skin cells. But this key vitamin is also found in fortified foods such as milk, orange juice, and breakfast cereal.
Getting your daily dose of vitamin D may keep colds at bay. A 2009 study from Massachusetts General Hospital found that lower vitamin D levels were associated with a greater risk of upper respiratory infections. In 2012, the same researchers found that Vitamin D supplements can help ward off kids’ winter colds, as well.
When it comes to mushrooms, your choices are many: White button, Portobello, shiitake, and Maitake are just a few of the varieties you’ll find in your grocery store. Fortunately, just about all mushrooms contain some form of immune-boosting antioxidants, along with potassium, B vitamins, and fiber.
Shiitakes, for example, contain lentinan, a nutrient that is thought to have anticancer properties. Other varieties, such as certain brands of Portobello, are grown in ultraviolet light to spur vitamin D production.
Skinless turkey breast
Lean proteins, such as turkey breast with the skin removed, are high on Ansel’s list of flu fighters. “We think we need protein to build muscle, and we do—but actually, we need it to build antibodies and fight infection in the body, as well,” she says.
Chicken, turkey, and pork are all good sources of protein, but you can also get plenty from meatless sources such as beans, nuts, and dairy.
The darker the greens, the higher the nutrient content. So when you’re shoring up your defenses for cold and flu season, choose arugula and kale over iceberg lettuce.
Bitter greens like arugula may even help relieve chest congestion, sniffles, and coughs. How? It’s not entirely clear, although a 2011 British study found that mice that were fed green vegetables had more infection-fighting white blood cells in their intestines than those who were not.
Ounce for ounce, pure cocoa contains more of the disease-fighting antioxidants known as polyphenols than most berries—and it’s loaded with zinc, to boot.
Too often, however, the nutritional benefits of cocoa are overshadowed by the sugar and saturated fat found in chocolate bars and other treats. To reap the immunity-boosting benefits without the unhealthy extras, stick with bite-sized portions—about one quarter-ounce per day—of dark chocolate with a cocoa content of 70% or higher.
Carrots and sweet potatoes
Orange fruits and vegetables, such as carrots and sweet potatoes, are rich in beta-carotene. When we eat these foods, our bodies convert this organic compound into vitamin A, which is essential for maintaining a strong immune system.
Vitamin A is especially important for areas that go haywire when we catch a cold: It keeps the mucous membranes that line our nose and throat—one of the body’s first lines of defense—healthy and functioning properly.
Whether you eat them in a bowl or a bar, oats contain a type of fiber called beta-glucan, known for its cholesterol-lowering and immune-boosting properties.
Animal studies have shown that beta-glucan from oats can help prevent upper respiratory tract infection, and a few controlled trials have suggested that beta-glutan consumption can alter white blood cell activity in humans, as well.