Fight Immune Decline With ReishiAugust 2014
By Walter Thompson
As we age, the steady decline of our immune system opens the door for infection and inflammation that underlies heart disease, diabetes, and cancer.1-4 Known as immunosenescence, the deterioration of a once-vital immune system hastens the decay of our body’s defenses and functions.5
In the search for remedies to ward off the dangers of immunosenescence, researchers have found that the medical mushroom known as Reishi contains multiple bioactive components that have a proactive effect on the immune system.
Ancient Chinese physicians discovered the multiple properties of Reishi and it has been used for centuries to promote health and longevity, which earned Reishi the title, “Mushroom of Immortality.”6,7
The complex compounds in Reishi have been shown to safely modulate an aging immune system, combat cancer, and reduce some of the causes of cardiovascular disease.6,8-12
Modern scientists utilizing sophisticated technology and laboratory studies are providing evidence backing more than 2,000 years of traditional use in China. Reishi mushrooms contain a multitude of the pharmacologically active compounds that may ward off various factors of aging.6
Reishi Balances Aging Immune Systems
A youthful immune system prevents infection by bacterial, viral, fungal, and other organisms, and also conducts immune surveillance to track, identify, and destroy abnormal molecular patterns that might indicate an early cancer.13 Furthermore, an optimal immune system is capable of slowing and stopping the inflammatory response to an invader once the threat had been neutralized.14
But over time, the immune system slows down in its normal function. There are three main results of this process known as immunosenescence.
- First, with a reduced immune function, a person becomes increasingly vulnerable to infections that can produce fatal pneumonia in older adults.15-18 Even with the widespread pneumonia vaccine coverage among elderly people, the death rate continues to climb due to the debilitating effect of immunosenescence and the increase in antibiotic resistance.16,19-22 Other infections, such as influenza and herpes viruses, also threaten older adults as their immunity wanes.17,23
- The second major impact of immunosenescence is an apparent loss of the immune system’s ability to identify and destroy emerging cancer cells. Cancer cells display unusual molecular patterns that a healthy immune system routinely recognizes and eliminates. With a decline in natural immunity, there’s an increased likelihood that malignant cells will escape detection and evolve into a full-blown tumor. This is one of the reasons why cancer is largely a disease of older people.5,24,25
- The third component of immunosenescence is loss of the ability to turn off the inflammatory response once the threat has been eliminated. With the inflammatory response switch left in the “on” position, this type of persistent, low-grade inflammation is potentially at the root of many “diseases” of aging, including cardiovascular disease, neurodegeneration, bone and joint disorders, and again, cancer.26-28
The numerous chemical components of the Reishi mushroom exert subtle, but powerful effects that may reverse many of the impacts of immunosenescence.29 Reishi extracts boost the function of dendritic cells, which help other immune cells recognize foreign antigens and destroy them.14,29,30
Reishi also promotes development of B and T lymphocytes, immune cells involved in the production of antibodies and the regulation of immune function.29 Extracts of Reishi enhance development of specialized “natural killer” cells that target viral invaders and cancer cells for destruction.8-10,29
Reishi Targets Age-Related Infections
Reishi mushrooms and their extracts have potent antiviral and antibacterial properties that can help protect the body from deadly microorganisms that threaten health as one ages.
Many of the components found in Reishi have been shown to inhibit infection of herpes simplex, the virus that causes cold sores and genital herpes. It also may defend against herpes zoster, reducing pain associated with shingles and demonstrating a treatment response in several manifestations of the herpes zoster virus in one pilot trial of a Reishi combination formula.31 Reishi components directly bind to the viruses,32 interfering with the process in which viruses attach to and enter healthy body cells in order to create an infection.33 Unlike medications, research showed that Reishi did not cause toxicity to cells.34,35
In patients who had already developed shingles, administration of Reishi extract was shown to dramatically reduce the painful effects of the viral outbreak.36 As with many natural therapies, Reishi is most effective against herpes viruses when it is administered prior to, rather than following, development of the infection.33,37
Influenza viruses are also the targets of Reishi mushroom extracts, which are rich in trace elements like zinc and selenium that are known to be essential for preventing viral infections and mitigating their severity.38-40 Studies also show that Reishi extracts potently inhibit the Epstein-Barr virus that causes mononucleosis syndrome and is also strongly implicated in several kinds of lymphomas.41-44 And Reishi extracts also target the hepatitis B virus, while protecting the liver against its damaging effects in preclinical research.45,46
Remarkably, Reishi extracts have now been shown to produce a dramatic drop in the number of active virus particles known as “viral load” in monkeys infected with simian acquired immunodeficiency syndrome (SAIDS), a model of the human HIV/AIDS disease.47 Laboratory studies demonstrate that active compounds from Reishi mushrooms act by inhibiting HIV enzymes called proteases: an action similar to that of some of the most successful anti-HIV drugs on the market.6 In this context, Reishi mushrooms have been said to have “huge potential for HIV drug discovery.”6
Components from Reishi increase the activity of cell surface receptors that trigger the release of inflammatory cytokines signaling molecules and thereby helping the immune system identify and destroy bacterial invaders.48
Reishi Immunomodulation Slashes Inflammation And Lowers Cholesterol
Inflammation is a major component of atherosclerosis and cardiovascular disease, which promotes the development of cholesterol-containing plaques and increases the tendency of platelets and white blood cells to stick to those plaques, further narrowing and blocking arteries.49,50 Reishi mushrooms’ potent immune-modulating properties have been shown to lower these inflammatory stimuli by reducing cells’ ability to stick to vessel walls and preventing the overgrowth of smooth muscle cells that stiffens and “hardens” arteries.49,50
But Reishi components have other means of improving cardiovascular health as well.
Polysaccharides from Reishi significantly reduced triglycerides and total cholesterol (including LDL) cholesterol after 12 weeks of supplementation in rats, while also raising HDL cholesterol levels.11,12 In the same experiments, Reishi supplementation lowered markers of oxidation, while increasing natural cellular antioxidant systems. Microscopic examination of the animals’ livers revealed a remarkable reduction in fatty degeneration of liver cells, an inflammatory stage that readily leads to cirrhosis and liver failure.11,12,51,52
Basic laboratory studies demonstrate that certain “sterol” compounds in Reishi can interfere with the cholesterol synthesis pathway in human cells, diminishing the amount of new cholesterol produced each day.53,54 This mechanism is similar to that of the statin cholesterol-lowering drugs, but operates on an entirely different enzyme system.55
Human studies with Reishi have been conducted in patients with mild hypertension and elevated blood lipids. While the results showed little change in blood pressure, the researchers found a marked reduction in serum triglycerides and a marked increase in HDL-cholesterol.
Additionally, the Reishi group saw better plasma insulin and insulin resistance results—a major risk factor for later cardiovascular disease development and diabetes—than the placebo group.56 Other research showed a reduction in the activity of an enzyme that contributes to elevated blood sugar and lipid levels.57
In diabetic rats, which like their human counterparts are at increased risk for atherosclerosis and heart disease, Reishi extract supplementation decreased fasting blood glucose and improved insulin concentrations in a manner comparable with the antidiabetic drugs metformin and rosiglitazone.58,59 The animals given Reishi had lower levels of free fatty acids, triglycerides, and total and LDL-cholesterol, and higher levels of beneficial HDL-cholesterol.58
Reishi’s Immunomodulation Protects Against Cancer
Reishi mushrooms have multiple mechanisms by which they fight the development and spread of human cancers.60 Studies suggest Reishi mushrooms have six potential anticancer mechanisms.61,62 Because of the numerous bioactive compounds contained in Reishi, many of these mechanisms are somewhat complex. We describe six of Reishi’s known anticancer mechanisms next:
1. Activation and modulation of the host immune system.
Natural killer (NK) cells identify abnormal cancerous tissue and attack it before it develops into a full-blown tumor.63 Immunomodulation is primarily the result of Reishi polysaccharides interacting with immune system cells, especially those in the spleen and the thymus, both sources of aggressive cancer-killing cells.9,10,64,65 Animal studies show that Reishi inhibited tumor growth and prolonged the lifespan of mice bred to carry cancers. Reishi stimulated normal immune function, even when the animals were treated after the tumors had developed.66
A preparation of Reishi extract markedly increased the ability of immune system cells to surround and destroy tumor cells in mice bearing a variety of human cancers. The extract also prevented the decrease in immune system function caused by exposure to ionizing radiation.67 Reishi polysaccharides also inhibit adhesion of the “coating” protein fibrinogen to cancer cells. This makes cancer cells more vulnerable to destruction by stripping them of the protection naturally afforded by fibrinogen, and making the cells more accessible to NK cells that can destroy them.8
Another compound from Reishi appears to bind to specialized cell receptors that trigger a sequence of events resulting in the destruction of malignant cells.68 And a series of unique long-chain fatty acids from Reishi is also able to modulate antitumor responses.69,70 Even Reishi proteins may play an active role in the inhibition of tumor cell growth.71
2. Direct killing of cancer cells.
Studies show that Reishi components not only decrease numbers of tumor cells, but also inhibit their ability to form colonies that spread into healthy tissue, while leaving healthy cells unaffected.72,73 These effects are powerful enough to augment the activity of the chemotherapy drug cisplatin.72
3. Inhibition of new blood vessel formation (angiogenesis).
Studies show that a polysaccharide/protein-like molecule from Reishi inhibited new vessel formation by up to 40% in a laboratory model of angiogenesis.74
4. Inhibition of cancer cell proliferation and invasion (metastasis).61,64,75
Reishi mushroom components reduce inflammatory signaling and estrogen receptor signaling in breast cancer cells, taking away two of the most potent promoters of cancer cell proliferation.76,77 In prostate cancer cells, Reishi induces a decrease in inflammatory signaling and slows cell proliferation.60,78 Reishi extracts also cause “cell cycle arrest,” in which the cell replication cycle becomes “locked” in one phase, making further replication impossible and stopping the growth of the tumor.72,79-82
An important component of Reishi, ganoderic acid, has been shown to inhibit tumor invasion by its ability to block a “protein-melting” enzyme called matrix metalloproteinase, or MMP.83-86 Cancer cells use MMP to dissolve away the protein matrix between normal cells, allowing them to squeeze their way through barriers and invade nearby tissues, and even enter the bloodstream to form metastases far away from the original tumor.86,87 Ganoderic acid has been shown to both inhibit prostate cancer cell growth and create an environment in bone tissue that is not favorable for the spread of the cancer.88
5. Deactivation of carcinogens.
This process protects cells from damage that may initiate cancer development.61 When rats were exposed to the powerful colon carcinogens azoxymethane or PhIP, those treated with higher doses of Reishi extract developed significantly fewer and/or smaller tumors than those given the carcinogen only.89,90 Similarly, fewer tumors developed in the lungs of rats treated with a lung carcinogen when the animals were treated with Reishi extracts.91
6. Promotion of programmed cell death (apoptosis).
With the process of programmed cell death (apoptosis), normal cells die when their useful lives are over. However, some cancer cells lose the ability to die off by apoptosis, and instead continue to proliferate endlessly, taking over healthy cells and organs.92,93 By increasing apoptosis, this kind of accelerated cancer cell death has been demonstrated in human cervical cancer and other cell lines after treatment with Reishi extracts, especially those containing ganoderic acid.62,72,94
These six specific properties have made Reishi extracts of special interest to oncology researchers who are studying highly aggressive and invasive cancers, especially of the breast and prostate.60,95,96 Inflammatory breast cancer is one such condition in which malignant cells do not form a cohesive tumor mass in the breast, but rather spread rapidly by forming tiny “spheroids” of cells that travel through the blood and lymphatic system, resulting in the appearance of multiple metastases throughout the body.97,98 Reishi’s ability to inhibit many of the steps in metastatic spread is now being actively explored as a means of stopping such deadly, invasive cancers.95-97
Today, Reishi mushrooms’ combined anticancer activities have been demonstrated in studies of lung, breast, prostate, ovarian, cervical, and colon cancers, both for prevention and for treatment of these devastating malignancies.62,64,88-91,94,97,99 Early clinical trials are especially encouraging.
One study in a group of 30 patients with advanced-stage cancer showed that 1,800 mg of a Reishi polysaccharide extract three times daily produced a sharp increase in immune function, including increases in tumor-fighting interleukin-2 and interferon-gamma and in natural killer cell activity.100 And another study in patients with precancerous colon lesions called colorectal adenomas demonstrated that a supplement dose of 1,500 mg/day of a Reishi extract for 12 months decreased the rate of appearance of at least one adenoma by 52% at 12 months; in contrast, the group receiving placebo experienced an increase in the rate of incidence of at least one adenoma by a dramatic 42% at 12 months. In this study, there was also a decrease in total size of tumors of 1.40 mm in supplemented patients, with an increase of 1.73 mm in untreated controls.101 The typical dose for normal aging people is about 1,000 mg each day of standardized Reishi extract, along with other natural components of the Reishi mushroom.