The immune system is a complex integration of intimately working parts that are constantly responding to stimuli. Close association between psychological, neurological, nutritional, environmental, and endocrinologic factors influence immune function. This supports the need for an integrative approach in the maintenance of good health.
Psychoneuroimmunology describes the interaction between the emotions, nervous system, and immune system and has been extensively studied and discussed in medical literature. The word “stress” is used so commonly it is often taken for granted, however, many clinical and experimental studies have clearly demonstrated its effect on immune function. According to a study by Rose, R.: Endocrine responses to stressful psychological events, Psychiatric Clinics of North America 3:251-75, 1980, individuals under stress release significant amounts of steroids (corticosteroids) and neurotransmitters (catecholamines) leading to an increase in intracellular cyclic AMP and decrease in cyclic GMP, ultimately leading to immunosuppression and increased susceptibility to illness. Although these systems work to maintain homeostasis, under- or over-stimulation of immune responses challenges our ability to maintain good health. This supports the relentless messages we receive to “slow down” and reduce our levels and responses to stress.
A healthy lifestyle makes a significant impact on the body’s ability to maintain good health and prevent against illness. Natural killer cells are lymphocytes, a type of white blood cell, which nonspecifically attacks and kills any infected cell or cancer cell. A variety of lifestyle practices have been shown to increase natural killer cell activity and enhance optimal immune function. These include adopting a more vegetarian diet and increasing intake of green vegetables, which provide essential vitamins, minerals, enzymes, and trace nutrients; eating regular meals; maintaining a proper body weight; sleeping an average of seven or more hours per night; exercising regularly; and not smoking.
The old adage “you are what you eat” not only makes common sense, but, is overwhelmingly true. The body attempts to metabolize and use every last morsel of food we ingest to supply the basic building blocks to maintain structure and proper function of our billions of cells. Poor food choices and deficiencies in key nutrients compromise our body’s ability to function. Optimal immune function requires a healthy diet that is rich in whole, natural foods, such as fruits, vegetables, grains, beans, seeds, and nuts; is low in saturated fat and trans fatty acids (fried foods); is low in refined sugar; contains adequate amounts of protein; and includes the consumption of five to ten glasses of clean water daily. Nutrients that especially support proper immune function include vitamin A, carotenes, vitamin C, vitamin E, vitamin B6, vitamin B12 and folic acid, iron, zinc, and selenium can be found in a wide variety of foods or can be supplemented in the diet.