In a 2006 study, researchers took 115 obese, sedentary, postmenopausal women and assigned half of them to stretching exercises once a week and the other half to at least 45 minutes of moderate-intensity exercise five days a week. Moderate exercise discharges tension and stress and enhances immune function. Quiet music can aid recovery from everyday hassles and may therefore buttress immune function. Massage has shown to improve immune function in studies of Dominican children with HIV. Stress-reducing activities such as meditation produce positive changes in the immune system. While most of us can’t move into a spa, we can learn to save our stress responses for true emergencies and not fire them up over stalled traffic, bad hair days and aphids on the begonias. Less often, chronic stress can promote a hyper-reactive immune system and aggravate conditions such as allergies, asthma and autoimmune disease. For instance, psychological stress raises the risk for the common cold and other viruses. While acute stress pumps up the immune system, grinding long-term duress taxes it.
When you’re stressed, your adrenal glands churn out epinephrine (aka, adrenaline) and cortisol. Compared with formula-fed babies, those nourished at the breast have fewer serious infections. If you’re a new mother, breast milk provides essential nutrients and immune system components to your developing child. Brigitte Mars, herbalist and author of The Desktop Guide to Herbal Medicines, notes that sugary foods and juices impair immune function research bears her out. While studies have focused on purified mushroom extracts, fresh shiitake and maitake (also called “hen of the woods”) mushrooms are delicious sautéed in a little olive oil. Medicinal mushrooms such as shiitake, maitake and reishi contain beta-glucans (complex carbohydrates) that enhance immune activity against infections and cancer and reduce allergies (cases of inappropriate immune system activity). Adequate protein intake is also important the source can be plant or animal. No, it’s those virtuous, self-righteous diets high in fruits, vegetables and nuts that promote immune health, presumably because they’re rich in nutrients the immune system requires. French fries, soft drinks and bourbon don’t build strong white blood cells either. Fortunately, there are ways you can strengthen your immune system. Other risks include chronic disease, poverty, stress, living with lots of other people (dormitories, low-income housing), and drinking tap water (with its local microbes) in many foreign countries. Surgery and wounds give microbes a chance to sneak into the inner sanctum. Some you can’t control: The very young and the very old are vulnerable. A number of factors affect immune system health. The answer is that not all immune systems function alike. You may wonder why one person hacking on the airplane successfully sickens the passenger to his right but not the one to his left. In that great expanse of active, productive life in between, you still get colds and flus and “stomach bugs.” You may wonder why you are sick more or less often than your partner, co-workers and neighbors. At the other end of life, your immune system wearies from years of fighting. Your immune system remembers the microbes it has encountered and protects you the next go around. You sniffle, scratch, cough, vomit, ache, sweat and shiver. You spend your first years catching colds, influenza and strep throat. Infections are as inevitable as death and taxes.