Food alone can't protect against the common cold or flu, and the science isn't yet clear on which nutrients may bolster immunity to reduce your risk of getting sick. But experts agree that a diet rich in a variety of produce, whole grains, lean proteins, and low-fat dairy products―along with adequate sleep, moderate exercise, and minimal stress―contributes to a well-functioning immune system and may promote a faster recovery if you do come down with a cold or flu. Here are some key nutrients and tips that will help increase the likelihood that you'll fly through the winter months in good health.
“An overall healthful diet rich in vitamins and minerals is your best bet for the cold weather months,” says Julia Zumpano, RD, of the Cleveland Clinic Department of Preventive Cardiology. “You’ll also benefit from other nutrients not typically found in supplements when you eat a whole food.” Zumpano encourages plenty of fruits and vegetables (for vitamins C and E); whole grains, lean meats, and poultry (for zinc); and low-fat dairy products (for vitamin A). For example, in addition to vitamin E, a whole grain like quinoa or rye bread offers fiber, B vitamins, minerals, and other nutrients, which support overall good health.
Choose citrus, like grapefruit, oranges, kumquats, tangerines, and clementines as well as canned tomatoes, chiles, or pineapple for vitamin C.
Pumpkin, butternut squash, and other deep-hued orange produce provide beta-carotene, which is converted in the body to vitamin A. The squash in this recipe is also packed with vitamin C, providing about half your daily needs per serving.
“Many studies have been done in nutrition and immune function involving numerous nutrients and come out with different, often contradicting results,” says Dayong Wu, PhD, a scientist in the Nutritional Immunology Laboratory, the USDA Human Nutrition Research Center on Aging, and Assistant Professor of the Friedman School of Nutrition and Science Policy at Tufts University. Because a nutritional intervention may have different effects on people of different ages or nutrition status as noted in scientific studies, Wu says, it’s difficult to make broad recommendations based on study findings.
However, zinc has been indentified with healthy immune systems, and it's a good idea to get enough of the mineral in your diet no matter what. One serving of this unique appetizer provides about 13 milligrams of zinc―that's all you need in a day.
Water is the largest single constituent of the human body―contributing to at least half your body weight―but it’s “also a forgotten nutrient,” says Jennifer K. Nelson, MS, RD, director of clinical dietetics at the Mayo Clinic in Rochester, Minnesota. This essential nutrient (meaning it’s one the body can’t produce on its own) promotes healthy muscle, bone, and blood. Adequate hydration is even more important once you’re sick because fluids lost through sneezing, watery eyes, and a runny nose need replacing. “When you have a mild fever, your body becomes more dehydrated as a result. So drinking plenty of fluids is probably the first line of defense,” Nelson says.
Water, coffee, tea, and juice, as well as water-filled foods such as fruit, vegetables, soups, and stews all count toward daily hydration needs.
Yogurt: The live active cultures in yogurt make it a probiotic, a source of good bacteria that may bolster the digestive system and improve regularity. Daily supplementation of probiotics during a three-month period shaved two days off common cold episodes and reduced the severity of symptoms, according to a German study of 479 participants published in journal Clinical Nutrition. The catch: No one knows exactly what dose―or which strains―of friendly bacteria work best for what conditions. But plain yogurt is a great way to gain calcium and potassium, both of which are linked with improved heart and bone health.
Green Tea: The catechins and other plant-based compounds in green tea may be linked to helping prevent colds and influenza. A study published in the Journal of the American College of Nutrition found that consuming green tea increased immune cells, boosting their ability to fight an affront to the system. In theory, that may translate to fewer colds and flu, says naturopathic physician Paul Anderson of Seattle’s Bastyr University. And if you get a cold, “it may be less severe,” he adds. The catch: “You’d need to drink at least eight to 10 cups a day of green tea,” Anderson says, to match the antioxidant amounts used in studies. If nothing else, green tea doesn’t seem to hurt, and a cup of hot tea contributes to your daily fluid needs.