Win the Cold War: 7 Ways to Boost Your Immune System

Cheyenne Ellis/FITNESS MagazineCheyenne Ellis/FITNESS MagazineBy Sharon Liao

Your virus-protection plan needs an upgrade, and no, we're not talking about the one for your computer or smartphone. Studies show that the average person comes down with a cold two to four times a year and that up to 20 percent of the population gets the flu. Fortunately, there are now more effective ways than ever to kick your immune system into high gear. Here's how to fine-tune your healthy habits to fend off any nasty germs that come your way.

Related: 5 Foods That Fight Colds and Flu

Stop the Sniffles
Healthy habit: You load up on plenty of colorful fruits and vegetables.
Power it up: Sure, vibrant-hued produce like kale and oranges have cold-fighting nutrients, but don't overlook their pale counterparts. White button mushrooms, for instance, can jump-start the body's natural killer cells, which attack cold and flu viruses, according to a study at Tufts University. "Mushrooms are abundant in a type of fiber, called beta-glucans, that can activate the immune cells," explains study author Dayong Wu, MD, PhD, the associate director of the nutritional immunology lab at Tufts. Incorporate shrooms in omelets, pasta, and stir-fries. While you're at it, toss in some garlic, too. Besides adding flavor, it will deliver a dose of allicin, a compound shown to fight off infections. "Use fresh cloves," suggests David Grotto, RD, a FITNESS advisory board member and the author of The Best Things You Can Eat. "Jarred garlic is pasteurized, which destroys the allicin." Chop garlic finely, then let it sit for about 10 minutes; the extra time allows the cloves' tissue to release the enzymes that create allicin. And be sure to add garlic at the end of the cooking process to prevent the heat from neutralizing it.

Healthy habit: You log seven to eight hours of sleep a night.
Power it up: The quantity of your slumber is important, but so is the quality. "Interrupted sleep may increase the production of stress hormones, which wear down the immune system," says Michael Breus, PhD, the author of The Sleep Doctor's Diet Plan. Case in point: When researchers at Carnegie Mellon University exposed study participants to a cold virus, those who didn't snooze as soundly were six times more likely to get sick than people who slept like a rock. To maximize your shut-eye, lace up your sneakers on most days of the week: Regular exercise is proven to help you doze off faster and spend more time in restorative deep sleep. If worries keep you awake, jot down everything you're fretting about, along with a solution for each, before turning in, Breus suggests. This will put your mind -- and your body -- at rest.

Healthy habit: You always, always wash your hands.
Power it up: If you're like the overwhelming majority of us, you're probably not sudsing up correctly. A study at Michigan State University found that 95 percent of people don't scrub for the recommended 20 seconds, and one in three doesn't use soap. Time one of yoursessions to see what a 20-second scrubbing feels like. "Wash the fronts and backs of your hands, around your wrists, between your fingers, and beneath the tips of your fingernails," says Daniel Uslan, MD, the director of the UCLA Health Systems antimicrobial stewardship program. Then dry thoroughly; germs cling more easily to wet surfaces. No sink in sight? Use a hand sanitizer that contains at least 60 percent alcohol.

Related: Beat These Sneaky Cold Culprits

Healthy habit: Exercise is a regular part of your daily routine.
Power it up: Working out strengthens your cold- and flu-fighting ability. But regularly pushing your limits can do more harm than good: One study in Australia found that runners who hit the treadmill at a challenging pace for an hour and a half experienced as much as a 50 percent drop in their production of immunoglobulin A, a germ-battling antibody, afterward. "Prolonged high-intensity exercise puts stress on your body, raising your chances of getting sick," says David Nieman, the director of the Human Performance Lab at Appalachian State University. For a healthier workout incorporate breaks into your routine. Nieman found that exercise with built-in pauses -- say, tennis, soccer or interval training -- doesn't have the same negative impact as running at a constant pace. Training for a long-distance event? Fueling properly can reduce the inflammation that weakens your immune system. If you're doing a workout that is 90 minutes long or longer, aim to get 120 to 240 calories' worth of carbs -- for instance, a banana and/or a sports gel -- during each hour of exercise.

Healthy habit: You carry a water bottle with you wherever you go.
Power it up: "Staying hydrated keeps your mucus membranes moist and helps your immune system function efficiently," says Neil Schachter, MD, the medical director of the Respiratory Care Department at the Icahn School of Medicine at Mount Sinai in New York City. Reusable bottles can breed bacteria, though, so wash yours with hot soapy water every day. Consider moisturizing the air you breathe, too. Cold and flu viruses thrive in dry air, so running a humidifier may be your ticket to a healthy winter. Researchers at the Centers for Disease Control and Prevention found that roughly 74 percent of flu-infected cells survived after an hour in a room with 23 percent or less humidity; only about 18 percent of the virus, however, survived in a room with 43 percent or more humidity. A humidifier can bring your space to 40 percent humidity (any higher than that can cause mold to grow).

Healthy habit: You skip greasy, sugary foods in favor of low-fat, low-cal soups and salads.
Power it up: A steady stream of light meals may leave you vulnerable to the bug that has your coworker coughing. A study from Drexel University suggests that a low-calorie diet hampers the body's immune response. Skip the deprivation-diet plan and load up on lean protein, healthy fats, whole grains and produce. "Snacks are an ideal way to get an extra dose of nutrients," Grotto says. Brazil nuts, for instance, are high in selenium, a mineral that can enhance white blood cell function, and yogurt is rich in good-for-you probiotics.

Healthy habit: You wipe down your desk every day.
Power it up: Use your disinfectant on common surfaces, too -- they're usually teeming with germs. The most contaminated objects in an office include the kitchen faucet, the microwave door handle, and water fountain and vending machine buttons, according to an analysis from the University of Arizona in Phoenix. "Cold and flu viruses can live outside the body for at least a few hours and up to four days," says study author Charles Gerba, PhD, a professor of microbiology. Keep a bottle of hand sanitizer in highly trafficked zones like the break room, and squirt some on your hands each time you enter or leave. That alone can reduce the occurrence of cold and flu by up to 80 percent, Gerba says.

Related: 8 Tips for Germ-Free Travel


Should You Pop That Pill?
Your sneezing colleagues are downing vitamin C, and your mom is forwarding e-mails about herbal remedies. Do any of these supplements even work? Check out our cheat sheet.

Vitamin C: Give it a try. Research is mixed, but taking 500 milligrams a day at the start of a cold may lessen your misery.

Echinacea: Skip it. Many studies show that it doesn't prevent colds.

Garlic: Give it a try. The benefits of fresh garlic are minimized in its supplement form, but even so, research suggests that garlic supplements may help prevent a cold and shorten its duration.

Vitamin D: Take it. A deficiency of D can raise your chances of getting an upper-respiratory infection. Though the RDA is 600 international units, 1,000 is often recommended.

Zinc: Give it a try. The jury is out. But some studies found that taking zinc lozenges at the first sign of a sniffle may hasten your recovery.

Sources: Neil Schachter, MD, Icahn School of Medicine at Mount Sinai, New York City; Cochrane Library; Advances in Therapy; University of Colorado School of Medicine;Annals of Internal Medicine.

Cold Comfort
Uh-oh. That tickle in your throat is the first clue that you're about to use up some of your sick days. By knowing what to expect and acting quickly, you can ease the symptoms and recover stat.

Days 1 and 2: You are tired and have a sore throat. Getting plenty of rest can strengthen your immune system; vitamin C tablets and zinc lozenges may help lessen the severity of a cold. If you are also running a fever and have body aches and/or chills, you may have the flu. Play it safe; see your doctor ASAP. She can prescribe an antiviral medication, which can reduce your misery by a day or two.

Days 3 to 5: You're sneezing, coughing, stuffed up, a little achy. Gargle with salt water and use a steam inhaler, like the Vicks Personal Steam Inhaler ($36, cvs.com), to help ease congestion. Take aspirin, ibuprofen, or acetaminophen for achiness; an antihistamine for sneezing; and cough syrup with the suppressant dextromethorphan.

Days 6 and 7: Except for the cough, which can linger, you're feeling better. To let your body fully recover, resist the temptation to resume your regular routine. Go to bed early and do a lighter-than-usual workout. If you're battling the flu, it will probably be another week before you're back to normal. If your symptoms don't improve, call your doctor to check for complications, such as bronchitis.

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