The function of the human immune system is to defend the body against invaders. Microbes (germs or microorganisms), cancer cells, and transplanted tissues or organs are all interpreted by a healthy immune system as non-self against which the body must be defended. Although the immune system is extremely complex, its basic strategy is simple: to recognize the enemy, mobilize forces, and attack.
   See swine flu for natural treatment inquiries on this epidemic.

Ways to maintain or boost Immune system
Deep sleep is one of the most important ways to boost the immune system and reduces the risk for catching the common cold and other viral and bacterial infections. Chronic insomnia can lead to immune system deficiency. One good way to make sure you sleep deeper and longer is by taking a long walk each day. Avoid all sodas, coffee, more than one cup of tea in the morning or day. These drinks can interfere with sleep and disturb your ability to fight infections.

Moderate exercise, at least 3 times a week, preferably daily walks. Excessive and prolonged physical activity temporarily reduces the function of the immune system. The negative impact of intensive training stress on immune function can be minimized by getting adequate sleep, minimizing psychological stress, avoiding periods of dietary energy restriction, consuming a well-balanced diet that meets energy and protein needs, avoiding deficiencies of micronutrients (particularly iron, zinc, and vitamins A, D, E, B6 and B12), ingesting carbohydrate during prolonged training sessions, and consuming - on a daily basis - plant polyphenol containing supplements or foodstuffs and Lactobacillus probiotics.
Avoid excessive sun exposure but have regular exposure to the sun or take at least 400 units of vitamin D a day. Some people with little or no sun exposure may require up to 2,000 units a day.
Reduce stress any way you know how. Stress releases the hormone cortisol which wreaks havoc with the immune system. Stress of any kind -- emotional, physical, psychological -- quickly damages the immune system.
Eat more fruits and vegetables. They have flavonoids that have anti-bacterial and anti-viral activity. Avoid excessive sugar intake. Consume more garlic, onions, and culinary herbs such as cloves. Berry fruits are rich sources of bioactive compounds, such as phenolics and organic acids, which have antimicrobial activities against human pathogens. Among different berries and berry phenolics, acai, cranberry, cloudberry, elderberry, raspberry, strawberry and bilberry especially possess clear antimicrobial effects.  Red grapes and blueberries contain compounds called stilbenoids, which work with vitamin D to increase expression of the human cathelicidin antimicrobial peptide (CAMP) gene.
Many mushrooms have immunity enhancing substances but it is best not to overeat them.
Ingest healthy probiotic bacteria. These friendly gut bacteria boost the immune system.
   Clin Exp Immunol. 2013. Differential effect on cell-mediated immunity in human volunteers after intake of different lactobacilli. The stimulation of CD8(+) T cells and NK T cells suggests that intake of probiotic bacteria may enhance the immune defense against, e.g. viral infections or tumors.
Reduce or eliminate smoking, this includes smoking marijuana. Inhaling pot smoke damages lung tissue. Keep alcohol consumption low or moderate.
Drink more tea (up to mid day) - Drinking tea appears to boost the immune system. Non-tea drinkers who downed two to four small cups of black tea per day for two weeks appeared to be better able to fight off bacterial infections. As an explanation for tea's benefits, experiments in the lab revealed that an ingredient found in black, green, oolong and pekoe teas boosted the ability of immune system cells to attack a bacterial invader. The experiments used ethylamine, which is produced when the tea ingredient L-theanine is broken down in the liver.
Get a massage. Massage therapy reduces cortisol levels.
Pray, meditate, listen to music, or find a way to still your mind.
Do yoga, or relaxed breathing and stretching, at least once or twice a week.

Herbs and nutrients that influence or boost the Immune system
On this page I mention certain herbs and nutrients that have an influence. I wish to emphasize that the research in this area is quite incomplete and we need to learn much more before making any definitive recommendations. As a general rule it is best to use these immune system booting herbs for a limited time or with breaks, as opposed to uninterrupted daily use for months and years. Too high a dosage or taking these herbs for too long without a break may actually reduce immunity or have positive or negative effects that we are not yet familiar with. Please realize that fruits (for instance berries) and vegetables contain many natural antimicrobial agents.
   There are countless supplements involved in supporting or boosting a healthy immune system, at least initially. The ones mentioned here are only a small fraction. You can visit each site to learn more. If you have an immune system deficiency or a weak immune system, discuss with your health care provider before taking any of these immune system supplements for prolonged periods. Also, please keep in mind that the term "boosting" is not a scientific term. The immune system is incredibly complicated and while certain aspects of it may be enhanced by a particular herb or dietary supplement, another aspect of it may be harmed.
   This whole issue is extremely complicated and it is very very difficult, practically impossible, to measure all the various factors and influences and the outcome from the use of the medicinal herbs and mushrooms. There are countless types of immune cells, globulins, hormones, different kinds of proteins and other substances that have an influence and it is nearly impossible to measure all their interactions and effects on the body over time. Each person is different depending on their genetics, diet, lifestyle factors, environment, sleeping habits, etc.

For an excellent, comprehensive, daily multivitamin and multi-mineral supplement, consider MultiVit Rx.

Flavonoids -- Most flavonoids, including Quercetin, have anti-germ activity. Quercetin also has Vision enhancing  properties, along with bilberry.
Colostrum has immune influencing compounds that could boost the immune system in certain individuals.
Garlic bulb has many medicinal properties, including anti-fungal, anti-bacterial, and anti-viral..
Vitamin C is known as ascorbic acid
Vitamin D supplementation is helpful to those who do not get enough sun exposure.
Vitamin E natural complex is preferable to synthetic dl alpha tocopherol
Zinc mineral is particularly important who are zinc deficient or have a diet which provides little amounts of this mineral.
Andrographis has become popular in Scandinavia for use during winter upper respiratory infections.
Astragalus is used by traditional Chinese doctors to stimulate the immune system. In a test tube study, Astragalus was found to have anti herpes simplex virus activity.
Beta glucan -- one mouse study shows daily ingestion of Beta-Glucan may offset the increased risk of upper respiratory infection associated with stress.
Cat's Claw (Uncaria tomentosa or Una do Gato) is a medicinal plant from the Amazon River basin that is widely used for inflammatory disorders. Cat's Claw is found in Joint Power Rx. This product contains glucosamine and chondroitin.
Echinacea plant extract is widely used for upper respiratory tract infections.
Elderberry has a number of important compounds including anthocyanins which are powerful antioxidants and have immune system boosting properties.
Goldenseal herb is often used as an immune system enhancing herb
Olive leaf extract (Olea europaea) contains several flavonoids including apigenin,  luteolin, chrysoeriol, hesperidin, rutin, quercetin, and kaempferol. Major isolated constituents in Olive-Leaf-Extract strongly inhibit the classical pathway of the complement system.
Oregano -- Numerous laboratory and animal studies indicate oregano has immune system stimulating effects, blood sugar control properties, antioxidant, and anti-fungal, anti-parasite, and anti-bacterial activities.
Probiotics including acidophilus and bifidobacterium -- Probiotics have been defined as live microorganisms that (when ingested) have a beneficial effect in the prevention and treatment of specific medical conditions. These microorganisms are believed to exert biological effects through a phenomenon known as colonization resistance, whereby the indigenous anaerobic flora limits the concentration of potentially harmful (mostly aerobic) germs in the digestive tract. Prebiotics have also been found to be of benefit in reducing the odds of catching a cold or flu.
Propolis from bee hives. Propolis supplement is sold over the counter.

Immune products available over the counter
Now Foods, Healthy Immune, Seasonal Immune Support, 24 Packets
Source Naturals, Wellness Formula, With Andrographis and Propolis Extract, 180 Tablets

Mushrooms and extracts
Agaricus
AHCC -- Active Hexose-correlated Compound - AHCC - is a mushroom extract that has been tested as an immune enhancing, liver protective and anti-cancer agent.
Cordyceps could be of benefit.
Maitake mushroom or extract could be of benefit.
Reishi is a the common medicinal Chinese herb, a fungus with a variety of biological activities. Reishi has long been used as a folk remedy for promotion of health and longevity in China and other oriental countries. The most attractive character of this kind of medicinal fungus is its effect on the immune system and anti-tumor activities.

Ann Transl Med. 2014. Immune-enhancing effects of Maitake (Grifola frondosa) and Shiitake (Lentinula edodes) extracts.

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Products formulated by a medical doctor
Mind Power Rx - for healthy brain function and memory enhancement
Passion Rx - highly popular sexual enhancement product for men and women
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5-HTP 50 mg - for serotonin support
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CoQ10 50 mg - for healthy energy metabolism and heart function
Curcumin the active extract from turmeric, found in curry spice mix
Tongkat Ali 200 mg - herbal libido enhancer from Malaysia and Indonesia
Mangosteen contains powerful xanthones with possible anti-cancer activities

Vitamins that lower immune system functions
Excess vitamin A can reduce immune function.

Nutrient intake and immune function of elderly subjects.
J Am Diet Assoc. 2008.
Food intake, aging, and immune function share complex influences. Therefore, the purpose of this study was to examine relationships between nutrient intakes from food and dietary supplements and a biomarker of immune function. Selenium, sodium, DHA, EPA, and vitamin A intake from diet and supplements were associated with better immune response. Excess vitamin A intake was associated with worse immune response.

Prevention of infection
Proper washing with regular soap and water works just fine to prevent the spread of germs and there is no clear evidence that antibacterial soaps, wipes and other products are any better.

Common words used to describe parts of the immune system
Antibody: A protein, made by B lymphocytes, that reacts with a specific antigen.
Antigen: Any molecule capable of stimulating an immune response.
Cell: The smallest living unit of tissue, composed of a nucleus and cytoplasm surrounded by a membrane. The nucleus houses DNA, and the cytoplasm contains structures (organelles) that carry out the cell's functions.
Immunoglobulin: A synonym for antibody.
Leukocyte: A white blood cell. Lymphocytes and neutrophils, among others, are leukocytes.
Lymphocyte: The main immune cell of the lymphatic system, further categorized as B lymphocytes (which produce antibodies) and T lymphocytes (which help the body distinguish self from nonself).
Macrophage: A large cell that engulfs (ingests) microbes after they have been targeted for destruction by the immune system.
Molecule: A group (aggregation) of atoms chemically combined to form a unique chemical substance.
Natural killer cell: A type of lymphocyte that can kill certain microbes and cancer cells.
Neutrophil: A large white blood cell (leukocyte) that ingests antigens and other substances.
Peptide: Two or more amino acids chemically bonded to form a single molecule.
Protein: A large number of amino acids chemically bonded in a chain. Proteins are large peptides.
Receptor: A molecule on the cell surface or in the cytoplasm that fits another molecule like a lock and key

The Lymphatic part of the Immune System
The immune system maintains its own system of circulation--the lymphatic vessels--which permeates every organ in the body except the brain. The lymphatic vessels contain a pale, thick fluid (lymph) consisting of a fat-laden liquid and white blood cells.

Along the lymphatic vessels are special areas--the lymph nodes, tonsils, bone marrow, spleen, liver, lungs, and intestines--where lymphocytes can be recruited, mobilized, and deployed to appropriate sites as part of the immune response. The ingenious design of this system ensures the ready availability and quick assembly of an immune response anywhere it is needed. This system can be seen at work when a wound or an infection in a fingertip leads to an enlarged lymph node at the elbow, or when a throat infection causes the lymph nodes under the jaw to swell. The lymph nodes swell because the lymphatic vessels drain the infection by carrying it to the nearest area where an immune response can be organized.

SSRIs, serotonin, and the immune system
Antidepressants like Prozac and Zoloft, which affect a brain chemical called serotonin, also influence the body's immune system. Prozac and Zoloft belong to a group of drugs called selective serotonin reuptake inhibitors or "SSRIs," which are thought to combat depression by causing serotonin to linger longer at nerve junctions. Serotonin also works as a signaling molecule between certain immune cells such as dendritic cells and T cells. The findings indicate that dendritic cells can pick up serotonin at sites of inflammation and then pass it to T cells, which influences their growth and division into new cells. Treatment with the antidepressant Prozac (fluoxetine) blocked this serotonin uptake. Further research is needed to better understand how SSRIs might affect the immune system, whether for the better or worse.

Immune system and employment
Have a career that satisfies you. The stress of unemployment may dampen healthy people's immune system function -- but the good news is that finding a job can restore its fighting power.

Immune System Research clinical trials
Older men who exercise regularly may not only keep themselves in good shape, they may also give their immune systems a boost. Physically active seniors who were injected with a protein to provoke an immune system reaction mounted an immune response similar to that seen in men half their age. Maintaining a physically active lifestyle may prevent or slow age-associated decline in immune function. Erythromycin, a widely used antibiotic long considered safe dramatically increases the risk of cardiac arrest, particularly when taken with some popular drugs for infections and high blood pressure.

Washing hands with soap can halve the number of young children suffering from pneumonia, the leading killer of youngsters under 5 years old worldwide. It can also greatly reduce cases of diarrhea and the skin infection impetigo.

The aging process can lead to a decline in immune function. In an article published in the December 2001 issue of the American Journal of Clinical Nutrition, thirty healthy elderly volunteers participated in a 3-stage dietary supplementation trial lasting 9 weeks. During stage 1, subjects consumed low-fat milk for 3 weeks as a base-diet control. During stage 2 (intervention), they consumed milk supplemented with bifidobacteria for 3 wk. During stage 3 (washout), they again consumed low-fat milk for 3 weeks. The results showed an increase in the ability of white blood cells to attack organisms or kill tumor cells after bifidobacterium consumption.  Dr. Sahelian says: bifidobacteria and other probiotics may be an effective dietary supplement for enhancing some aspects of the immune system in the elderly.

Methicillin-resistant staphylococcus aureus is a microbe found naturally on the skin of healthy people. It is a particular threat to patients whose immune system is weakened and is particularly dangerous in hospitals. This bug has become resistant to some of the most advanced drugs ever made, but researchers found garlic reduces its effectiveness in the body. Other research suggests garlic may work against fungal infections and parasites, and that it may increase the body's resistance to viruses, including the common cold.

Practical recommendations for immune-enhancing diets.
J Nutr. 2004 .
Immune system -enhancing diets contain nutrients that have putative benefits, including arginine, n-3 fats, glutamine, nucleotides, and structured lipids. Although under most circumstances the systemic inflammatory response is beneficial to the host, improving the eventual outcome of injury, infection, or inflammation, excessive proinflammation (leading to cardiac, hepatic, and mitochondrial dysfunction) or excessive counterinflammation (leading to immune depression) can worsen outcome. In critically ill septic patients, the synthesis of arginine can be exceeded by its catabolism to nitric oxide (NO) and urea, rendering arginine conditionally essential. In septic patients, supplemental arginine might further increase NO levels and be potentially harmful through excessive proinflammation. However, administration of increased amounts of arginine might improve immune function in surgical and trauma patients by increasing NO production in macrophages. When the diet provides at least 1 g of the (n-3) fatty acids eicosapentaenoic and docosahexaenoic acid combined, 2-series eicosanoids (prostaglandins, prostacyclins, thromboxanes) are replaced partially by 3-series eicosanoids, and 4-series leukotrienes are replaced partially by 5-series leukotrienes that are less proinflammatory. Thus, the effects of arginine and (n-3)-fat supplementation might be expected to be complementary-arginine might improve cytokine and NO production in patients with immunodepression, whereas (n-3) fats might be beneficial when there is excessive proinflammation, particularly when supplemental arginine is supplied, by reducing cytokine-induced eicosanoid production.

Anti-tumor and immunoregulatory activities of Ganoderma lucidum and its possible mechanisms.
Acta Pharmacol Sin. 2004.
Ganoderma lucidum is a medicinal fungus with a variety of biological activities. Reishi has long been used as a folk remedy for promotion of health and longevity in China and other oriental countries. The most attractive character of this kind of medicinal fungus is its effect on the immune system and anti-tumor activities. Large numbers of studies have shown that reishi modulates many components of the immune system such as the antigen-presenting cells, NK cells, T and B lymphocytes. The water extract and the polysaccharides fraction of reishi exhibited significant anti-tumor effect in several tumor-bearing animals mainly through its immune system enhancing activity. Recent studies also showed that the alcohol extract or the triterpene fraction of reishi possessed anti-tumor effect, which seemed to be related to the cytotoxic activity against tumor cells directly. Preliminary study indicated that antiangiogenic effect may be involved antitumor activity of reishi.

Exposure to Bacteria
Shopping cart handles are the most bacteria-infested items among some commonly used objects while doorknobs on public bathrooms are not as bad as might be expected. The Korea Consumer Protection Board tested six items that are commonly handled by the public and ran tests for their bacteria content.
Shopping cart handles led the way with 1,100 colony-forming units of bacteria per 1.55 sq inches followed by a mouse used on computers in Internet cafes, which had an average of 690 colony-forming units. Hand straps on buses were next with 380 units, followed by bathroom doorknobs at 340. Rounding out the list were elevator buttons at 130 colony-forming units and hand straps on subways at 86. Washing hands with soap removes almost all of the bacteria.

emails
Q. There has been lots of news about the potential "bird flu" epidemic that could explode in the US. Is there anything people can do to possibly counter it with natural supplements? Perhaps to strengthen one's immune system? Does Dr. Sahelian plan to write about it in his newsletter?
     A. At this time, we don't have any specific information on how to fight bird flu naturally except for the usual steps to enhance one's immune system as mentioned on this web page. But if we do find something, we will mention it.

Q. When someone takes foods or supplements that are said to improve the immune system, such as ginseng, noni or spirulina, is there an increase in the number of white blood cells in the body? And if so wouldn't this register in blood tests as an increase in the "white blood cell count, and therefore lead doctors to think that there could be an infectious process going on? (I don't exactly don't know how this works so I'm really not sure). Thanks much.
     A. This is a good question. The immune system is extremely complex. It involves not only white blood cells, but several other types of cells and countless chemical substances. Different herbs and substances have different effects on the immune system, and the same supplement could have a different effect on different people. Plus, the dose could influence the outcome. The same herb may stimulate some aspects of the immune system at one dosage and inhibit it a a different dosage. Also, there could be some short term stimulation but if taken for prolonged periods there could be interference. There are so many factors involved that it is nearly impossible to predict how well a supplement works to enhance the immune system unless it is studied by itself in varying dosages for varying time periods in a large group of people of different ages. If an herb does elevate white blood cell counts, it is unlikely that most will elevate it to a degree that would be of concern.

When using immune boosting supplements like astragalus, medicinal mushrooms, etc., is it OK to take them at the same time or is it better to alternate, say 2 months using Astragalus, then 2 months using medicinal mushrooms, etc.? I've read different things. Some say one's body can "get use to" a supplement and it may not be utilized as it's meant to be. Others say it's OK to combine them because they are, actually, like food and can boost the immune system.
   Every single person has a unique and extremely complicated immune system that changes on a daily basis depending on a number of factors including diet, sleep, stress, etc. It is impossible to predict which regimen is most effective, but, as a general rule, I prefer not taking a particular immune booster more than a week at a time without a break.

What's the role of a glyconutrient and the immune system? Can glyconutrients boost the immune system.
   I have a full discussion on glyconutrients here.

I would like to know how to boost immune system, or supplements to take if you are a cancer survivor. I recently had a small tumor removed that was found to be b-cell lymphoma. All scans and labs show that it is gone completely and my doctor has said that there is no need for chemo. My question is what supplements would help to avoid any recurrence? Which would boost my NK cells and my immune system as a whole? Besides the basics like vitamin C and E, Astragalus etc., I have read about medicinal mushrooms, Graviola, Iscador from Germany and many more. I would love to hear the good Doctor's opinion.
   Each person's case is unique, and it is impossible to predict how a person's immune response will boost or respond to different supplements since there is such a wide possibility of interaction between other dietary factors, sleep patterns, stress, other supplements used, dosage of supplements, timing of supplement taken, other medicines used, physical activity level, climate, season, etc.

Do you carry an immune system formula? Are any of these effective for avian flu?
   Since each person's immune system is unique, and since certain herbs may boost the immune system in the short term and have unknown effects in the long term, is it difficult to create an immune system formula that would be of benefit to a large number of users. See also information at flu vaccine.

I work for Prevention magazine. We had one of our readers send us a question, and we'd like to get an expert answer. The question is, "Is there any supplement to boost immunity during times of high stress?"
   The most important factors that improve immunity include an overall healthy diet, moderate exercise, and getting a deep sleep. As to supplements, there are many that could be considered and each nutrition expert has their favorites. Some of these include bovine colostrum which has immunoglobulins, garlic pills, certain mushrooms and extracts such as cordyceps and beta glucan, simple vitamins such as vitamin C, herbs such as oregano, astragalus and andrographis, and probiotics. It is difficult to know in any one individual which supplement or combination would be helpful, and in what dosages. I would suggest trying each one separately for a week or two and to not take more than 3 or 4 at any one time. It is a good idea to take breaks from the use of herbal supplements.

You provide very impressive responses in the categories I have browsed, confidence boosting and a valuable quick check as to whether or not medical research has been done in an area. Congratulations. ( In fact I have emailed the link to my daughter, a busy medical doctor!). My question is regarding immune boosting and immune dampening, both of which seem to be needed by people with autoimmune disorders. If a person is trying to "dampen" an inflammatory immune response with appropriate supplements, as in a Hashimoto's / CFS flare , would it be 'contradictory' in one's body to then continue taking one's daily immune "boosting" supplementation, or say, to add in boosts such echinacea, andrographis, astragalus when one feels a cold coming on? This is a real dilemma to me! Meanwhile, I have subscribed to your newsletter.
   This is a good question. Most likely, if the herbs are being used for a few days or a week or two, I don't suspect there would be any problems using them in those who have autoimmune conditions. However, problems may potentially arise if they are used for prolonged periods.

I like from you is recommending some supplement, preferably natural, which I can take throughout my life which will support and build my immune system, and like some people say for SUN CHLERELLA and APRICOT SEEDS, these kill the cancer cells, I want something like this, if you can guide me I will be very obliged and thankful to you,
    I can't give specific advice since each person is different, has a different body chemistry, different diet, activity level, environment they live in, etc.

Our son has low immunoglobulin IGA, IGG, and IGM do you have anything that could help him?
    A doctor has to examine the whole patient and review all studies before making specific recommendations. It is not a wise idea to make recommendations based solely on results of selective testing.

Do you know of any treatment for d. fragilis? I'm scared the doctor is going to throw an antibiotic at my 7-year old grandson who has an already very damageds gut.
    Dientamoeba fragilis is a single celled parasite found in the gastrointestinal tract of some humans. In some people it causes gastrointestinal upset while in others it does not. One has to evaluate the whole person before giving any suggestions and we can't based on this limited info.

I have a question about taking adaptogenic herbs, medicinal mushrooms and supplements to prevent cancer and fight disease...I am Really ignorant about how the body works and don't know if there are any markers to check for ? how much does it take to overstimulate the immune system and actually promote disease ?So many substances in combination are used for their synergistic effect. How do we know the when its enough?
   The whole issue is extremely complicated and it is very very difficult, practically impossible, to measure all the various factors and influences and the outcome from the use of the medicinal herbs and mushrooms.

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