SUPERCHARGE YOUR IMMUNE SYSTEM

Fight cold and flu with these simple tips.

With the flu at epidemic levels this season—at last count it was still causing misery in 37 states—keeping your immune system in fighting form is a must. “The immune system is our body’s main line of defense against the bacteria, viruses, fungi and parasites that try to cultivate infections there,” says Janko Nikolich-Zugich, M.D., Ph.D., head of the department of immunobiology at the University of Arizona Health Sciences in Tucson. It can even put the brakes on rogue cells that could turn into cancer.

But while you may know where your circulatory and digestive systems are, the immune system is harder to pinpoint. “Because its purpose is defense it has to be everywhere,” says Nikolich-Zugich. Every part of your body—including the lymphatic system, cardiovascular system, GI tract, sexual reproductive system, airways and skin—is lined with immune cells.

When a microbe determined to make us sick attacks, the immune system leaps into action, releasing special proteins, molecules and cells to kill the invader, wherever it may be. That process triggers an inflammatory response—characterized by redness, swelling, heat and pain—that subsides once the immune system has done its job.

But starting around age 65, the production of immune cells drops and your immune system weakens. That may be why people 65 and older account for about 90 percent of flu- and pneumoniarelated deaths each year, why it takes longer for wounds to heal in older people and why the risk of cancer rises as you age.

Generally, what’s good for overall health is also good for your immune system. Here are eight simple strategies that’ll help keep yours in fighting form.

Get your shots.

A vaccination imitates an infection, prompting your body to produce substances that will fight the disease if you’re ever exposed to it.

If you haven’t yet gotten your annual flu shot, it’s not too late—the flu can hang around until May. (It takes about two weeks for protection to kick in.) You also need a tetanus booster every 10 years. And if you’re 50-plus, ask your doctor about the shingles and pneumonia vaccines.

Work up a sweat.

Moderateintensity exercise such as brisk walking helps the immune system fight respiratory viruses, according to a 2009 study in Exercise and Sport Sciences Reviews. Aim for at least 20 minutes a day.

Get enough sleep.

People who slept fewer than six hours per night were about four times more likely to develop a cold than people who got seven hours or more, according to a 2015 Sleep study. Lack of sleep also may weaken your immune system’s response to vaccines, making them less effective.

Clean up your diet.

“There’s no one superfood that will ramp up the immune system,” says Walter C. Willett, M.D., professor of nutrition at the Harvard T. H. Chan School of Public Health. Instead, eat a well-balanced diet rich in fruits, veggies and whole grains. If that leads to weight loss, all the better: Australian researchers found that obese people with Type 2 diabetes or prediabetes who lost an average of 37 pounds had more than an 80 percent drop in cells that trigger inflammation.

Load up on D.

Most of us don’t get enough of this essential nutrient for immune system health, says Willett. Take a daily supplement containing at least 600 IUs of D or eat vitamin D–fortified cereals or juices.

Keep the cocktail count in check.

While moderate drinking may be good for the heart, too much alcohol suppresses the immune system so your body is less able to fight infection and even cancer. Women should have no more than one drink a day and men no more than two.

Don’t smoke.

Cigarette smoking keeps levels of infection-fighting white blood cells high, upping your risk for heart attack, stroke and cancer. And it makes it harder for wounds to heal.

Take up a relaxing hobby.

Singing in a choir, for example, may benefit your health: British researchers report the activity increases levels of cytokines—an immune system protein that helps fight illness—in cancer patients. In fact, anything that feeds your soul is likely to be good for your body.