Supporting Immune Response with Nutritional Supplements
By Jim English and Ward Dean, MD
Colds and flu are upper respiratory viral infections that are relatively harmless when compared to the growing threat of antibiotic-resistant ‘super bugs’. The long term effects of antibiotic overuse are beginning to hit home. And with the emergence of new and more virulent strains of flu, AIDS, and other immune disorders, we may be at the limits of what antibiotics can deliver.
Once considered exotic and found primarily in hospitals, antibiotic-resistant pathogens are rapidly becoming evident in commonplace settings. Following decades of over-prescribing and misuse, researchers and scientists now face the end of the ‘Golden Age’ of antibiotics. Antibiotic resistance appears ‘to be on the verge of desperation,’ said Nobel laureate Joshua Lederberg, who chaired an Institute of Medicine panel that met last May to discuss global efforts to fight the growing problem.
Among the growing strains of resistant pathogens that are emerging:
Staphylococcus epidermidis is a bacteriim found primarily in skin tissue. Once considered a non-threatening contaminant, it is now a leading cause of hospital-acquired bloodstream infection. More than 80 percent of Staphylococcus epidermidis found in US hospitals is now methicillin resistant. Recent studies have found S. epidermidis to be resistant to quinolones, cephalosporins and vancomycin.
Drug-resistant Streptococcus pneumoniae (DRSP) is a growing threat. Streptococcus pneumoniae infections – including pneumonia, sinusitis, meningitis and otitis media – are a leading cause of death and illness among the elderly, young children and persons with underlying medical conditions. Penicillin, the most often used antibiotic, will no longer work on 40 percent of S. pneumoniae cases.
Staphylococcus aureus, a common cause of skin infections, endocarditis (heart valve infection), osteomyelitis (bone infection) and sepsis (blood stream infection), first evidenced signs of resistance to the drug methicillin in the 1960s. Since then S. aureus strains have shown resistance to penicillins, macrolides, fluoroquinolones and lincosamides.
Vancomycin-resistant enterococci (VRE) is a major cause of hospital-acquired infection. VRE has become resistant to virtually all antibiotics, including vancomycin.
The result of these changes is that doctors now have to work harder to fight these infections while researchers race to develop new antibiotics. Although new agents, such as Synercid¨ (quinupristin / dalfopristin), are slowly being developed, the genie may be out of the bottle for good. Bacteria are extremely capable of adapting to new antimicrobial weapons. Without drastic controls on how antibiotics are used, new strains will continue to evolve, at a rate faster than science can match.
Nutrition for Immunity
Humans lived for millions of years without pharmaceutical antibiotics. Pharmaceutical antibiotics were introduced into medicine in the 1930s to 1940s. Prior to that time, physicians and their patients relied primarily on antimicrobial substances like colloidal silver, antispetics like alcohol and hydrogen peroxide, and various plant extracts which stimulated the body’s own defense mechanisms. This latter approach – that of stimulating the body’s defenses – is rarely considered today in ‘orthodox’ medicine. Although there are few immune-stimulating pharmaceutical drugs available today, there is a number of immune-enhancing nutrients and herbs that can dramatically energize a flagging immune system, and help overcome an attack by bacteria and viruses.
Herbs have been used for centuries in virtually every culture in the world. Native American medicine relied heavily on the use of herbs, and traditional herbal remedies are still commonly prescribed in Eastern countries such as China, Korea, and Japan as well as Europe. Over time, trial and error led to the development of folk medicines, and the most effective remedies were passed down through the generations. Herbs have been used in an attempt to treat nearly every known affliction and disease, with mixed results.
While some herbs have been shown to be ineffective, others have stood the tests of time and research, proving their worth. The following examples point out how nature has provided us with safe, effective methods of improving our health and quality of life.
In traditional Chinese herbal medicine Astragalus is believed to promote and enhance the immune system, replenish the ‘defensive energy’ and accelerate wound healing.1-3 A. membranaceus, the form of Astragalus used for medicinal purposes, is believed to enhance immune function by altering the metabolism of immune cells. Studies in both humans and laboratory animals have demonstrated a potent antiviral potential via its ability to protect against infection from the viruses that cause influenza and the common cold. Both oral and nasal administration of Astragalus extracts have offered protection against the common cold. In patients who are susceptible to colds and flu, treatment with Astragalus for short periods of time (two weeks) enhanced interferon induction by the white blood cells, resulting in increased levels of cytokines (such as interleukin-2 and IgA and IgG).
Astragalus treatment leads to an increase in T-helper cell activity. This increase in immune function was clearly demonstrated in one study where immuno-deficient and healthy normal mice were treated with Astragalus extract.3 This effect has been noted in humans as well. When mononuclear cells from cancer patients and healthy volunteers were inoculated with extracts of Astragalus, not only did T-cell levels rise to levels similar to that of healthy cells (prior to treatment), T-cell levels in cells from healthy individuals were also significantly increased.
Echinacea, an herb native to North America, has played an important role in Native American medicine. It was used by numerous tribes to treat a variety of symptoms and diseases, including: sore mouth and gums, toothache and coughs, and as an anti-inflammatory and antiseptic agent.4
More recently Echinacea has been closely examined for its influence on immune cell proliferation, antibody production, and antiviral activities.5 One of the most popular uses of Echinacea is for support and recovery from the common cold and influenza. Two recent studies support the use of Echinacea for this purpose.
In the first study, 108 patients with colds received either Echinacea or placebo for eight weeks.6 Of those patients receiving the Echinacea, 35.2% recovered and remained healthy, while only 25.9% of the placebo group remained healthy. When the patients did become infected, the length of time between infections was 40 days for the Echinacea group vs. only 25 days for placebo. When infection did occur in patients receiving Echinacea, effects were less severe and resolved quicker. Patients showing evidence of weakened immune system (CD4/CD8 ratio) benefited the most from Echinacea.
In a second study, 180 patients with influenza were given either an E. purpurea Echinacea extract or a placebo. The group receiving Echinacea showed significant reduction of cold symptoms.7
Additional human studies have shown similar immune system activity. For example, patients with inoperable liver cancer, following treatment with echinacea, experienced a dramatic reduction in the side effects associated with chemotherapy and an enhanced quality of life, improved immune function, and a significant rise in natural killer cell activity with CD4 levels.8 Some of these protective effects are mediated by the increase in cytokine production, such as increased levels of tumor necrosis factor-alpha (TNF-a) and interleukin-1 (IL-1).
In addition to its immunosupportive actions, Echinacea has also demonstrated mild antibacterial activity, due largely to echinacoside, a complex caffeic acid derivative found in high concentrations in the root of E. angustifolia. Echinacoside has been shown to have antibacterial action against Staphylococcus aureus, Corynebacterium diphtheria, and Proteus vulgaris.1,9,10
Cat’s Claw (Unicaria tomentosa), a woody vine that grows in Peru, is a traditional phytomedicinal of the Ashaninka Indians. The Ashaninkas drink a tea made of the bark once every week or two for general health. In the event of an illness, they consume about a liter every day until all symptoms have disappeared.
Both the root and the bark of Cat’s Claw, a liana growing to 100 feet or more, are sources of a rich variety of pharmacologically active compounds. Among some of the compounds found in U. tomentosa are catechins, alkaloids, ellagic acid and other phenolic antioxidants which are beneficial in the treatment of specific types of cancer. The most immunologically active alkaloids, the oxindole alkaloids, isopteropodine and pteropodine, have been found by Dr. Klaus Keplinger, an Austrian researcher, to stimulate immune function. In addition, the presence of glycosides, proanthocyanidins and beta sitosterol help provide anti-viral, anti-tumor and anti-inflammatory support for the body.
Ginseng has been used for centuries in China, Japan, Korea, and parts of the former Soviet Union for its supportive role in maintaining health. As an adaptogen, Ginseng is believed to produce a state of increased resistance to stress, supporting our ability to resist disease by building up our general vitality and strengthening our normal body functions.
Soviet researchers have been particularly keen on ginseng and have claimed their studies show the herb and its extracts can boost immunity, inhibit cancer, increase energy and physical stamina and have variable effects on blood pressure and blood sugar.
A recent study found that ginseng helps prevent symptoms of the common cold and improves antibody response to influenza vaccine. For 12 weeks, 227 volunteers who visited three private medical practices in Milan received daily oral capsule doses of either 100 mg of a standard Ginseng extract or a placebo. During the fourth week they received an influenza vaccination. There were only 15 cases of influenza or common cold in the group receiving the ginseng extract, versus 42 cases in the group receiving the placebo. By the eighth week, antibody titers rose to an average 272 units in the ginseng group, versus only 171 units in the placebo group. Additionally, at both the eighth and twelfth weeks, natural killer cell activity was nearly twice as high in the Ginseng group versus the placebo group.11
Antioxidants And Immune Support
Infectious diseases are a growing threat worldwide. Recent studies have shown how antioxidants may play an important role in the treatment of viral diseases.
Antioxidants not only reduce disease symptoms, but may also reduce the long-term effects of chronic oxidative stress, which has been linked to the development of cancer from some viral infections. Oxidative stress is seen in individuals infected with influenza, immunodeficiency virus and hepatitis.12
Vitamin C has seemingly been at the center of nutritional research, particularly with regard to the common cold. It is well known that Vitamin C is a powerful antioxidant, and this protective activity is now proving vital in recovery from infection. A number of studies have found that, during infection there is a marked decrease in vitamin C levels in plasma and white blood cells. The concentration of vitamin C in phagocytes and lymphocytes is over 10 times greater than in plasma, and low intake of vitamin C has been shown to decrease phagocytic activity in animal models.
Other studies have shown that higher vitamin C concentration increases the proliferative responses of T lymphocytes in vitro. Vitamin C has also been reported to induce the production of interferon in cell culture, and one study has found a correlation between natural killer cell activity and vitamin C concentration in leukocytes. Under in vitro conditions, vitamin C has been found to inactivate viruses and bacteria. In human studies doses higher than 100 g per day have been used for severe bacterial and viral infections.13
In a recent study, Italian researchers found that 2 grams per day of ascorbic acid (vitamin C) was effective in restoring bronchial responsiveness in hospital workers suffering from upper respiratory infections. The authors suggest that ascorbic acid can effectively re-establish the redux state in inflamed airways and may prove beneficial for treatment of coughs during upper respiratory infection.14
Vitamin E is the body’s premier fat-soluble antioxidant, and complement of vitamin C, the premier water-soluble antioxidant. Vitamin E is the major protective antioxidant for cell membranes, the dynamic matrices on and in which most of the body’s metabolic activity occurs.
Just as vitamin E protects serum lipoproteins and regulates prostaglandin balance, new research suggests that vitamin E supplementation may enhance phagocytosis, cell-mediated immunity, humoral immunity, and reduce the effects of stress on the immune response. 15
In an animal study on heart disease in the elderly, aged mice were fed vitamin E at 500 parts per million 2 months before exposure to influenza. These animals were found to have substantially lower amounts of the influenza virus in their lungs than control mice given smaller amounts at 30 parts per million.16
A related study on age and immune response involved 47 subjects, aged 61 to 79 years. Researchers reported that those receiving a supplement containing vitamin E and other micronutrients showed a significant increase in immune response. Specifically, an increase in CD57 natural killer cells, T-cells and T-cell subsets. Conversely, in the placebo group there was a decrease in T-cells, CD4 cells and the CD4:CD8 ratio. Researchers concluded that nutritional intervention provided an effective approach for delaying the overall decline in immune function noted with increasing age.17
Vitamin A is one of the best documented nutrients for supporting immune function. A deficiency in vitamin A is known to reduce resistance to infection by lowering neutrophil phagocytosis, cell-mediated immunity, humoral response and interleukin II production. Recent research has found a strong link between vitamin A intake and upper respiratory infections.
One 1996 study of newborn infants recorded substantial decreases in upper respiratory infection in newborns given 50,000 IU of vitamin A versus a placebo. Researchers concluded that neonatal vitamin A supplementation reduces infant mortality rates, as well as lessens the severity of respiratory infection.18
A second study linking vitamin A intake and respiratory infection followed 28,000 children between six months and six years of age. Higher intake of vitamin A was strongly associated with fewer upper respiratory infections, lessened incidence of diarrhea and a reduction in cough and fever. Of notice, there was a significant positive association with vitamin A intake and the lowered incidence of cough alone, a sign of a healthy respiratory epithelium.19
N-Acetyl Cysteine (NAC) has been extensively researched for its antioxidant properties, particularly in its potential to neutralize the chemical by-products of smoking. NAC has been used for bronchial congestion for over thirty years, and is used to fight chronic lung diseases because of its ability to break up mucus. However, one of the most exciting areas of NAC research is in the area of immunology. NAC has been found to significantly enhance human T-cell function, especially in older individuals. NAC is currently undergoing clinical trials around the world as an augmenter of immune function in people with AIDS. Its ease of conversion to both extracellular and intracellular glutathione, coupled with its stability and long half-life in the body, makes it an economical and powerful antioxidant.
Selenium plays a vital role in immune support. A deficiency of selenium results in depressed immune function, whereas selenium supplementation augments and restores proper immune system function. Selenium helps with the development of all white blood cells. In one study, individuals with normal selenium blood concentrations received 200 micrograms per day. This alone resulted in an 118 percent increase in the ability of lymphocytes to kill tumor cells and an 82.3 percent increase in the activity of a white blood cell known as a ‘natural killer cell’ because of its powerful ability to kill cancer cells and microorganisms.
For over 2000 years Reishi mushrooms (Ganoderma lucidum) have been recognized by Chinese medical professionals as a valuable remedy. As the ‘Medicine of Kings’, Reishi is widely used for different purposes. It is used for symptomatic relief of arthritis and of menopausal anxiety. It is also used in treating allergic asthma, hypertension, hypothyroidism, bronchitis, insomnia, general anxiety and stress, and cardiovascular problems. Reishi also is often the main ingredient in herbal formulas for immune dysfunction syndromes, such as Chronic Fatigue Syndrome.
Reishi is prescribed in China for a number of psychiatric and neurological afflictions, including diseases involving the muscles, anorexia, and debility following lengthy illnesses. In an eight-month study of Alzheimer’s disease in Japan, patients taking a Reishi mycelium product demonstrated significant improvement.
Recently, Russian scientists have taken an interest in Reishi. They found that in addition to the cardiovascular benefits mentioned above, Reishi showed a significant preventive and therapeutic action against plaque build-up (‘Plaque’ is a fatty compound which is comprised of a combination of oxidized cholesterol, calcium, and degenerated white blood cells [‘foam cells’]. It is deposited on the walls of arteries which restricts blood flow by narrowing the passage within arteries resulting in arteriosclerosis).
In 1990, researchers at the University of Texas Health Science Center in San Antonio found that Reishi could be effectively used in treating stiff necks, stiff shoulders, conjunctivitis (inflammation of the fine membrane lining the eye and eyelids), bronchitis, rheumatism, and improving ‘competence’ of the immune system without any significant side-effects.
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8. Brown DJ. Phytotherapy review and commentary. Townsend Letter for Doctors. Aug/Sept: 789, 1992.
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10. Grieve M. A Modern Herbal, edited by F. Leyel, Hafner Press, New York. NY, p 265, 1974.
11.’Efficacy and Safety of the Standardized Ginseng Extract G 115 for Potentating Vaccination Against Common Cold and/or Influenza Syndrome,’ Scaglione, F., et al, Drugs in Experimental and Clinical Research, 1996;22(2):65-72.
12. The formation of nitric oxide also occurs in viral infection. ‘Oxidants and Antioxidants in Viral Diseases: Disease Mechanisms and Metabolic Regulation,’ Peterhans, Ernst, Journal of Nutrition, 1997;127:962S-965S.
13. ‘Vitamin C and Infectious Diseases,’ Hemila, Harri, in Vitamin C in Health and Disease, Packer, Lester and Fuchs, Jurgen (eds.), 1997;Chapter 27:471-503. 27873 [inf] PEARL
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16.’Vitamin E May Ward Of Heart Disease as Well as Flu,’ Stenson, Jacqueline, Medical Tribune, May 23, 1996;2
17. ‘Effect of Vitamin and Trace Element Supplementation on Immune Indices in Healthy Elderly’, Pike, Jennifer and Chandra, Ranjit, Kumar, International Journal of Vitamin and Nutrition Research, 1995;65:117-120.
18. ‘Impact of Neonatal Vitamin A Supplementation on Infant Morbidity and Mortality,’ Humphrey, Jean, H., ScD, et al, Journal of Pedia.