Infections are as inevitable as death and taxes. You spend your first years catching colds, influenza and strep throat. You sniffle, scratch, cough, vomit, ache, sweat and shiver. Your immune system remembers the microbes it has encountered and protects you the next go around. At the other end of life, your immune system wearies from years of fighting. 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. You may wonder why one person hacking on the airplane successfully sickens the passenger to his right but not the one to his left. The answer is that not all immune systems function alike. A number of factors affect immune system health. Some you can’t control: The very young and the very old are vulnerable. Surgery and wounds give microbes a chance to sneak into the inner sanctum. 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. Fortunately, there are ways you can strengthen your immune system.
1: Eat Like Peter Rabbit. Malnutrition impairs immune function. French fries, soft drinks and bourbon don’t build strong white blood cells either. 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. Adequate protein intake is also important; the source can be plant or animal.
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). 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.
One substance to avoid is simple sugar. 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.
If you’re a new mother, breast milk provides essential nutrients and immune system components to your developing child. Compared with formula-fed babies, those nourished at the breast have fewer serious infections.
2: Stress Less. When you’re stressed, your adrenal glands churn out epinephrine (aka, adrenaline) and cortisol. While acute stress pumps up the immune system, grinding long-term duress taxes it. For instance, psychological stress raises the risk for the common cold and other viruses. Less often, chronic stress can promote a hyper-reactive immune system and aggravate conditions such as allergies, asthma and autoimmune disease.