Stress -- A person's stresses make his or her immune system both weaker and more prone to over-react. First, stress stimulates the release of corticosteroid hormones, and these suppress both arms of the immune system -- so it's less able to ward off invading viruses, bacteria, or parasites. Second, stress can make the immune system over-reactive. For example, stress increases the release of chemicals called histamines, so inflammation signals are sent out at a shout instead of a whisper. As a result, an allergen that would once give you no more than a few sneezes could now lead to hives or asthma. Stress also seems to play a role in the development and severity of autoimmune illness.
Nutritional deficits -- Like an army at war, your immune system consumes resources at an amazing rate when it fights an infection. For example, an activated B-cell will produce about a thousand antibodies per second before dying in a day or two. Therefore, the immune system needs a big stockpile of nutrients, so if your body is depleted, a lack of protein or a shortage in any one of numerous nutrients -- such as vitamin C or zinc -- will lower its resistance to disease. For example, Jan has had numerous patients who were suffering from frequent colds start getting much fewer after changing their diet to eat more protein and take routine supplements.
Weakened thymus -- Stress is linked to a shrinkage of the thymus gland and a drop in its immune-regulating hormones. Nutrient shortages -- especially antioxidants -- make this gland much more susceptible to the effects of aging. Additionally, surges in estrogen -- such as those during pregnancy -- inhibit the thymus, sometimes with lingering effects.
Fetal tissue -- Long after a woman has given birth, some cells from her baby will normally remain within her body. It is possible that the immune system may interpret those fetal cells as "foreign," putting it on red alert, now more likely to over-react and develop an auto-immune disease.
Other systems of the body -- If a family member has disturbed digestion -- like constipation, diarrhea, gas or "tummy aches" -- that can decrease the absorption of the vital nutrients the immune system needs. Additionally, it increases the chance of developing a food sensitivity (like an allergy), which activate your immune system needlessly.
Similarly, changes in the nervous system -- such as the stress of going back to school -- can lower the potency of the immune system. Depression, for instance, is associated with slower rate of recovery from illness and less effective white blood cell activity.
Finally, hormones bind to immune cells throughout the body, sometimes telling them to hit the gas and other times the brakes. For example, low estrogen can lower the effectiveness of a woman's immune system. On the other hand, healthy levels of estrogen, progesterone, oxytocin and prolactin help control overzealous immune function. Rapid fluctuations in these hormones -- from stress, weaning, new pregnancies, etc. -- can lead to hair-trigger immune responses, increasing the chance of an autoimmune disease.
Assessment of the immune system
Routine office visits with your doctor do not usually detect subtle abnormalities in the status of your immune system. These are diagnosed with tests that doctors generally order only if you mention some of the signs and symptoms described in the box. Basic tests of immune function include a complete blood count (CBC), white blood cell count (WBC), or sedimentation rate (a general index of inflammation). Additional tests can assess specialized elements of the immune system, such as helper T-cells.
To make sure that the immune system is getting all the necessary building blocks, it's often wise to assess a person's nutrition, both by reviewing his or her diet and through specific laboratory testing. You can also find out if a child or parent's body has grown over-reactive to certain foods -- wheat and milk products are the most common offenders -- by asking for a food sensitivity test.
Food sensitivities make it harder to digest what you eat and get the nutrients you need. Plus they can trigger a general immune system alert, making a person more prone to allergic reactions or to developing an auto-immune condition. Nutritional assessment and testing for food sensitivities are generally most readily available from holistic, licensed health practitioners.
Strengthening and balancing your immune system
Probably the single, most important thing you can do for a person's immune system is mental, not physical: a positive outlook, social support and low stress will nurture the healing powers of the body of any child or grown-up. Since angry quarrels depress immune system function, you'll also benefit from finding positive ways to discipline children in calmer, more peaceful ways, as well as to work out issues with your partner.
Second, promoting overall wellness will support the immune system in numerous ways. In particular, try to get lots of deep sleep -- both your children and you! -- since that's when the brain and body produce several substances that enhance immune function.
Further, good nutrition, a balanced digestive tract, and effective detoxification are vital allies to a potent immune system.
Third, you'll want to keep the overall load on your immune system as low as possible. You can do so by minimizing your exposure to toxins, allergens (including foods to which you are sensitive), or infection.