The quality of an individual's immune system can be evaluated through the balance of cytokines it is producing. This increasingly popular classification method is referred to as the Th1/Th2 balance. Interleukins and interferons are called “cytokines” which can be grouped into those secreted by Th1 type cells and those secreted by Th2 type cells. Th1 cells promote cell-mediated immunity while Th2 cells induce humoral immunity. These two different methods exist by which the body fights infections. While cellular immunity (Th1) directs Natural Killer T-cells and macrophages to attack abnormal cells and microorganisms at sites of infection inside the cells, humoral immunity (Th2) results in the production of antibodies used to neutralize foreign invaders and substances outside of the cells.

In many cases, an infection is fought with both arms of the immune system. At other times predominantly one is needed to control an infection. A healthy immune system is both balanced and dynamic: it should be balanced between Th1 and Th2 activity, switching back and forth between the two as needed. This allows for a quick eradication of a threat and then a return to balance before responding to the next threat. The inability to respond adequately with a Th1 response can result in chronic infection and cancer; an overactive Th2 response can contribute to allergies, various syndromes and play a role in autoimmune disease. In end stage illnesses, both arms of the immune system fail.

Two mechanisms are at work contributing to the development of chronic diseases.

• Pathogen defense mechanisms. When an immature immune cell is exposed to a virus, cancer, yeast, or intracellular bacteria (for example mycoplasma or chlamydia pneumonia), a Th1 response should be initiated. Viruses, especially herpes viruses such as EBV, CMV or HHV6, make proteins that mimic a particular cytokine. By this means the virus deceives the immune system into thinking that the threat is not coming from a virus. The immune system counters with too little of a Th1 response, the virus remains concealed and the infection becomes active or chronic. It is now thought that many, if not most, pathogens have this defensive ability.
• Immune system imbalance. In the above example, the virus has increased its chances of survival by diverting an immune system which is out of balance. It would have been able to respond more accurately if it were healthier. Immune system health is influenced by how we eat and think, our exposure to chemicals and our genetic heritage. In effect we are being judged as individuals for the poor lifestyle decisions we and our parents have made and as a society for not living in greater harmony with nature.

A failure of the Th1 arm of the immune system and an overactive Th2 arm is implicated in a wide variety of chronic illnesses. These include AIDS, CFS, candidiasis, multiple allergies, multiple chemical sensitivities (MCS), viral hepatitis, gulf war illness, cancer and other illnesses. If these two arms of the immune system could be balanced by stimulating Th1 and decreasing Th2, then many of the symptoms associated with these chronic illnesses would diminish or disappear and we would have found the answer to immune restoration and balance or the equivalent of a cure.

A possible line of therapy being investigated by the medical community is to reintroduce some of these cytokines to people who have severe immune deficiencies. This approach can be tricky because large amounts of any particular cytokine can have serious side-effects. Furthermore, their half-life in the body is usually relatively short and they are expensive.

One point to remember for general application with naturally occurring or synthetic immuno-modulators is that when they are taken continuously, at the same dose, they may become less effective. The dose must vary so that the immune system does not reset itself to the old balance point. Adjust the dose up and down as well as stopping use from time to time.

There are many natural agents available to help restore balance in an underactive Th1 arm. These include:
Omega-3 fatty acids, monounsaturated fats found in olive and hazelnut oils, vitamin A cod liver oil, l-Glutamine, Silica, digestive enzymes, friendly intestinal flora or soil based organisms (SBOs), ginseng (Red Korean or concentrated Siberian Ginseng extract), chlorella (spirulina and some other sea vegetables may have similar benefits), thyroid hormones, garlic (raw or aged extract), l-Glutathione (or products that raise levels), DHEA or AED (androstendiol), UV-A light, vitamin E, transfer factor (antigen specific) - protein immunomodulators extracted from colostrum, colostrum, low dose naltrexone, IP6, lentinian and certain other mushrooms, Thymus extracts, licorice root, dong quai, beta 1,3-glucan, noni, neem, gingko biloba, exercise, water (to aid detoxification), a positive attitude and prayer, the ability to forgive and be compassionate, and having long-term goals.

Factors that induce Th2 cytokines and suppress cell-mediated immunity. Processed, heated vegetable oils high in trans-fatty acids and linoleic acid (safflower, soy, canola, corn and sunflower), glucose (white sugar), asbestos, lead, mercury and other heavy metals, pesticides, air and water pollutants, progesterone, prednisone, morphine, tobacco, cortisol (in high doses), HIV, candida albicans, HCV, E coli and many other pathogens, continuous stress, thalidomide, UV-B light, pregnancy, melatonin (conflicting research suggests that high levels induce Th2 cytokines while very small amounts induce Th1 cytokines), alcohol (animals studies show that ethanol definitely suppresses Th1 cytokines and induces Th2; beer was not tested and there are some indications it may help), streptococcus thermophilis (sometimes found in yoghurt), candidiasis, circulating immune complexes (CICs - caused by a combination of leaky gut syndrome and poor digestion of proteins due to a lack or HCl and digestive enzymes), sedentary lifestyle, negative attitudes, low body temperature, acid saliva pH, chronic insomnia, inability to dream, weight lifting, and steroids (for muscle gain).