Building Winter Immunity

Photo: ©iStockphoto.com/Ryan J. Lane

How to mobilize your defense system to keep viruses from sabotaging your winter adventures

By Linda Lindsay

The human immune system is a complex and amazing thing. While you’re going about your day, working, exercising, eating and sleeping, your body is hard at work detecting harmful invaders, mobilizing immune cells into battle, and designing custom-made antibodies to destroy pathogens.

You’d be hard pressed to find a part of your body that’s not involved in the immune process. The major players are the thymus gland, spleen, bone marrow and lymphatic system. But immune activity also takes place in the liver, digestive tract, tonsils and skin. On the cellular level, the white blood cells (T-cells, B-cells and natural killer cells) are on the front lines of attack, while the chemical messengers interferon and interleukin coordinate the effort. Even your saliva, tears and mucous membranes play defensive roles by providing the first barrier to germs.

Although your immune system appears to work like magic, it needs a little support from you to function optimally. This is especially important as winter approaches and people spend more hours indoors, where germs spread more easily from one person to another. The stakes are even higher now, with the rising threat of the H1N1 flu virus.

Here’s how to keep your immune system in top form this winter.

Get moving

Moderately intense aerobic exercise benefits the immune system by increasing activity of macrophages (cells which surround and destroy invaders) and boosting white blood cells. Resistance training is an effective immune booster, too; lifting weights three times a week has been shown to improve the activity of natural killer cells.

But don’t overdo it, or you may find yourself flat on the couch instead of making turns in fresh powder.

Colleen Conners-Pace, an exercise physiologist at Tahoe Forest Hospital’s Tahoe Center for Health and Sports Performance in Truckee, says that “chronic cardio” (working out at too high an intensity or too frequently, even at moderate intensity) causes overtraining, which leads to chronic stress and can weaken the immune system.

“Chronic cardio allows no time for adaptation to take place,” says Conners-Pace, “so we never realize the benefits we work so hard for, whether it is improved fitness, weight loss, or peak performance.”

Conners-Pace suggests doing easier workouts more frequently, and harder workout less often but with greater intensity. Use your intuition to make sound workout decisions, she says. Signs of overtraining include a morning resting heart rate that is 10 percent or more above normal, insomnia, appetite loss, lack of desire to workout, chronic sore throat, excessive sleep, energy lulls during the day, or digestive irregularities.

Hit the sack

The immune system uses a large number of active cells that require sleep to regenerate. Case in point: when you’re sleep deprived, your body produces fewer natural killer cells.

Scrub up

Since viruses enter the body primarily through the nose, mouth and eyes, the simple act of hand washing can reduce the number of colds you get by almost 50 percent. Suds up with regular soap and warm water at least four or five times a day. If soap and water aren’t available, alcohol-based hand sanitizers are equally effective.

It may surprise you to learn that the Centers for Disease Control actually discourages the use of “antibacterial” soaps by anyone but those in clinical settings. Why? Antibacterial soaps have been shown to be no more effective in preventing infections than regular soap. Also, antibacterial soaps target primarily bacteria, and are only mildly effective against viruses that cause colds and flu.

Additionally, using these soaps incorrectly leads to a number of problems. Antibacterial soaps don’t actually kill bacteria, but rather disable them. To use these soaps correctly, you need to scrub for at least 45 seconds, rinse, and scrub again for another 45. Anything less, and you’re allowing the strongest bacteria to survive. Since no one but clinical staff washes their hands for a minute and a half (try it – it’s an interminable amount of time) using antibacterial soaps in household settings promotes the creation of super-bugs – strains of bacteria that are becoming resistant to life-saving antibiotics.

Furthermore, the active ingredient in antibacterial soap, triclosan, resists breakdown by water treatment plants. Once in the environment, triclosan is toxic to important species of algae, converts to dioxin in the presence of sunlight, and accumulates in fatty tissues of animals all the way up the food chain.

Get the right nutrients

You can’t eat junk food and expect your immune system to rally when a pathogen attacks. To function optimally, your immune system needs a vast array of nutrients, particularly vitamins A, C, E, the B complex, iron, selenium and zinc. Give your body the support it needs by eating primarily whole, unprocessed food; veggies, fruit, legumes, whole grains and healthy fats – monounsaturates and Omega-3s. Limit saturated and trans fats, alcohol and sugar, all of which suppress the immune system. But let’s admit it—no one eats perfectly, so you might want to fill in nutritional gaps with a multivitamin and mineral supplement.

Try Adaptogens

Adaptogens are plant substances that strengthen the immune system and increase the body’s ability to withstand stress. They are considered safe to take year-round. (Pregnant or nursing women should first consult with their physician.)

Astragalus (A. membranaceous.) This herb was shown in a study of 1,000 Chinese people to successfully shorten and prevent colds. It is thought to encourage white blood cells to produce more interferon, an antiviral chemical messenger. Many people find Astragalus effective in preventing sinus infections. Children can take half the adult dose.

Medicinal mushrooms, including reishi, shiitake, maitake and cordyceps are used widely as immune boosters in Asia and are gaining popularity here. Research shows that combinations of mushrooms may be more effective than single species. One such product, Host Defense, by New Chapter, contains 17 different mushrooms.

Eleuthero (Eleutherococcus senticosis.) Also called “Siberian ginseng,” Eleuthero is not a true ginseng. It contains immune-boosting compounds shown to flight flu and increase mental alertness and productivity. In a study of male athletes, those taking eleuthero increased their exercise duration and stamina by 23 percent, and recovered faster after workouts.

Ashwagandha. In lab and animal studies, Ashwagandha increased white blood cell count and other measures of immunity. The herb promotes physical endurance and stamina; however, it may have a mildly sedating effect on some people.

Manage your stress

Many studies have verified what we already know—the immune system is weakened by stress. Researchers believe that stress hormones hinder immune cells by binding to their receptor sites. But if stress can make you sick, the reverse is also true. Relaxation, meditation and even laughter increase immune cell count and activity. Studies of school-age and college students found that those who were taught stress management techniques had fewer and shorter colds, and the benefits lasted more than a year.

The key is to find an activity that de-stresses you. This might be meditation, yoga, a backcountry ski, a bike ride with friends, or collapsing on the couch and watching a good comedy. The activity should leave you feeling relaxed and renewed.

Get Bodywork

Chiropractic and acupuncture both strengthen the immune system. Chiropractic corrects misalignments that affect nerves leading to the organs. Acupuncture helps the body adjust during seasonal changes.

Linda Lindsay is a Truckee resident who writes about health and fitness issues. Her favorite ways to fight off colds and flu are cross-country skiing, lots of laughter, and taking Astragalus and medicinal mushrooms.