Immune Function

The immune system is an intricate network of specialized tissues, organs, cells, and chemicals. The lymph nodes, spleen, bone marrow, thymus gland, and tonsils all play a role, as do lymphocytes (specialized white blood cells), antibodies, and interferon.

There are two types of immunity: innate and adaptive. Innate immunity, which is present at birth, is the first barrier against microorganisms. For example, the skin, mucus secretions, and acidity of the stomach act as a barriers to keep unwanted germs away from more vulnerable tissues.

The second immune system barrier to infection, called adaptive immunity, is acquired later in life, for example after an immunization or successfully fighting off an infection. The adaptive immune system retains a memory of all the invaders it has faced. This is why people usually get the measles only once although they may be repeatedly exposed. Unfortunately some bugs such as the viruses that cause the common cold, “disguise” themselves and must be fought off time and again by the immune system.

Dietary changes that may be helpful: All forms of sugar (including honey) interfere with the ability of white blood cells to destroy bacteria.¹ ² Alcohol (a common ingredient in drug-store cold and cough remedies) interferes with a wide variety of immune defenses.³ Excessive dietary fat reduces natural killer cell activity.⁴

When the common cold/sore throat and ear infections continually recur, many nutritionally oriented physicians consider whether allergies may be a contributing factor. Many medical doctors treat ear infections with antibiotics or surgery and drainage tubes. Neither approach appears to work.⁵ ⁶ The link between allergy and ear infection has been well documented.⁷ Frequently these infections disappear when the food (often milk) causing a reaction is avoided.

Lifestyle changes that may be helpful: The immune system is suppressed during times of stress, while optimal nutrition helps maintain a strong immune system and combat the harmful effects of stress. Other challenges to a healthy immune system include chronic insomnia, over-work, and the aging process. Immunity gradually declines over the years, increasing susceptibility to infection. Exercise increases natural killer cell activity, which may help prevent infections.⁸ ⁹

Nutritional supplements that may be helpful: Zinc supplements may increase immune function.¹⁰ ¹¹ Some nutritionally oriented doctors recommend zinc supplements for anyone with recurrent infections, suggesting 25 mg per day for adults and lower amounts for children (depending on body weight).

A double-blind study of 100 men and women with colds provided half of the group with lemon-flavored zinc gluconate lozenges containing 13.3 mg of zinc to dissolve in the mouth, every two waking hours for the duration of their cold symptoms. The other half of the group unknowingly received a supply of dummy lozenges developed to have a medicinal taste similar to the zinc lozenges.¹²

The zinc lozenge takers reported fewer days of coughing, headaches, hoarse voice, stuffy nose, nasal drainage, or a sore throat. In fact, while the average cold sufferer reports symptoms lasting for 7.6 days, zinc lozenge users stopped experiencing cold symptoms after just 4.4 days. Because the affects of zinc gluconate on the cold happen only with lozenges, it may be that the zinc helps not by stimulating immunity but by killing viruses topically in the throat.

Vitamin A is needed by a healthy immune system. Vitamin A supplements have helped vitamin A deficient children with measles or infectious diarrhea in many studies.¹³ Without enough vitamin A, microorganisms can penetrate skin and mucous membranes (including the lungs). Infections may cause a reduction in the body’s ability to store vitamin A; without normal storage, extra vitamin A may be necessary.

Vitamin C stimulates the immune system in part by elevating interferon levels, which accounts for this vitamin’s anti-viral activity.¹⁴ In a Japanese study, surgical patients receiving transfusions were given 2 grams per day of vitamin C and didn’t contract hepatitis, a common problem in post-operative patients.¹⁵ A second study claiming to show that patients receiving vitamin C had not benefited actually demonstrated a 29% lower risk of contracting hepatitis though these results were not statistically significant.¹⁶

Harri Hemilä at the University of Helsinki, Finland, after reviewing twenty double-blind studies, reports that while vitamin C has only a small effect in preventing a cold, it does reduce a cold’s duration and severity. In fact, vitamin C given in therapeutic doses (1 to 8 grams per day) at the onset of a cold reduces the duration of cold episodes by as much as 48%. This effect appears to be dose-dependent—that is, the greater the dose of vitamin C taken, the stronger the effect.¹⁷

Lactobacillus acidophilus, the friendly bacteria found in yogurt, produces acids that kill invading bacteria.¹⁸

Are there any side effects or interactions? (Refer to the individual supplement for complete information.) Some people report that zinc lozenges lead to mild problems, such as nausea, mouth irritation, and a bad taste. People taking zinc for more than a few weeks should take copper as well. Taking too much zinc (several hundred milligrams per day for an adult) will actually depress immune function and must be avoided.¹⁹ Women who could become pregnant should not take more than 10,000 IU of vitamin A per day.

Some individuals develop diarrhea after as little as a few thousand milligrams of vitamin C per day, while others are not bothered by ten times this amount. However, high levels of vitamin C can deplete the body of copper—an essential nutrient. It’s prudent to ensure adequate copper intake at higher intakes of vitamin C (copper is found in many multi-vitamin/mineral supplements). There are no reported side effects with even large intakes of acidophilus.

Herbs that may be helpful: Echinacea helps support healthy immune function.²⁰ Echinacea lowers the risk of colds and upper respiratory tract infections. Many people use 40 drops of the tincture two to three times per day for six to eight weeks; echinacea in capsule form is also commonly available.

Garlic has natural antibiotic abilities. Supplementing with garlic increases natural killer cell activity in AIDS patients.²¹ ²²

Complex polysaccharides present in astragalus and the maitake mushroom have the unique ability to act as “immunomodulators” and, as such, are researched for their potential role in AIDS. The primary polysaccharide, beta-D-glucan, is well absorbed when taken orally and is currently under review as a supportive tool for HIV infection.

Green tea has been shown to stimulate production of immune cells and has anti-bacterial properties.^{24 25 26}

Preliminary research suggests that fo-ti plays a role in a strong immune system and has antibacterial action.²⁷

Ashwagandha is considered a general stimulate of the immune system,²⁸ as well as being considered as a tonic or adaptogen²⁹—an herb with multiple, nonspecific actions that counteract the effects of stress and generally promote wellness.

The main active compound in ligustrum is ligustrin (oleanolic acid). Studies, mostly conducted in China, suggest that ligustrum stimulates the immune system.³⁰

Are there any side effects or interactions? (Refer to the individual herb for complete information.) Echinacea is essentially non-toxic when taken orally. People shouldn’t take echinacea without consulting a physician if they have an autoimmune illness, such as lupus, or other progressive diseases, such as tuberculosis or multiple sclerosis. Those who are allergic to flowers of the daisy family should take echinacea with caution. There are no known contraindications to the use of echinacea during pregnancy or lactation.

Most people enjoy garlic; however, some individuals who are sensitive to it may experience heartburn and flatulence. Because of garlic’s anti-clotting properties, persons taking anticoagulant drugs should check with their doctor before taking garlic. Those scheduled for surgery should inform their surgeon if they are taking garlic supplements. There are no known contraindications to the use of garlic during pregnancy and lactation.

Unprocessed fo-ti roots may cause mild diarrhea. Some people who are sensitive to fo-ti may develop a skin rash. Very high doses may cause numbness in the arms or legs.

Nutritional Supplements

Herbs

Homeopathic Remedies

No homeopathy commonly used for this condition

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