CHAPTER TWO
THROUGHOUT THIS BOOK, we describe how medicinal mushrooms can promote good health. Mushrooms strengthen the immune system. They contain substances such as terpenoids and beta glucan that awaken the immune system and give it a boost. Mushrooms have a beneficiary effect on prebiotics in the gastrointestinal tract. They are adaptogens, substances that help the body adapt during times of stress.
Beta glucan, terpenoids, prebiotics, adaptogens—are these terms unfamiliar? They are explained in this chapter. This chapter provides the scientific background for the rest of the book. Here, you will find descriptions of the medical processes and medical terminology that pertain to medicinal mushrooms. We wrote this chapter to help you make wise decisions when it comes to taking medicinal mushrooms and other health supplements.
Problems in the immune system come in two varieties. When the immune system is underactive, it makes you susceptible to infections and cancer. When it is overactive, it may create allergies and autoimmune reactions. Autoimmune means the immune system is overstimulated and mistakenly attacks the body. Diseases such as diabetes, lupus, and lymphoma are autoimmunity diseases. AIDS, hepatitis, the flu, and colds, on the other hand, are associated with a weakened, underactive immune system.
As more research is conducted on medicinal mushrooms, it has become evident that some of them are immunoregulators. An immunoregulator is any substance that can quiet or activate the immune system, depending on circumstances. An immunoregulator quiets an overactive immune system; it increases activity when the immune system is sluggish. Basically, an immunoregulator triggers the production of white blood cells when the system is underactive, and it lowers their number when the system is overactive.
The optimal immune system is alert and ready to battle disease, but it is not overactive. An overactive immune system can cause autoimmune disorders such as allergies and create trouble of its own. As immunoregulators, medicinal mushrooms can help the body attain an optimal immune system. Mushrooms can help the immune system stay wide awake and strike the perfect balance between overactivity and sluggishness.
Many physicians believe that a greater emphasis on strengthening the immune system is overdue. Rather than concentrate all their efforts on treating disease, these physicians believe in teaching their patients to prevent disease as well. A good diet, getting the right amount of exercise, managing stress, and getting enough sleep all strengthen the immune system. Another practical way to fortify the immune system is to include medicinal mushroom products in your diet. Medicinal mushrooms have a proven effect on macrophages, T cells, and other important agents of the immune system.
Statistics such as these, which pertain to people in the United States, underscore the need to maintain a strong immune system:
Compromised immune systems have also given rise to lasting disorders such as diabetes, eczema, irritable bowel syndrome, chronic fatigue syndrome, and Epstein-Barr disease. By some estimates, as much as seventy percent of the United States’ health care budget is devoted to treating people with chronic ailments. About a third of the people who suffer from them can’t go to work or attend school.
In order to understand all the different ways that medicinal mushrooms can help strengthen the immune system, a little background is necessary. The next handful of pages outlines the immune system and its major components.
In the course of a single day, the body may encounter billions upon billions of bacteria, microbes, viruses, parasites, and toxins. When you get a cut or an insect bite, bacteria and viruses enter your body. When you draw a breath, bacteria and viruses enter your lungs. When you take a bite of food, millions of germs enter your digestive tract. How the immune system handles these invaders is extremely complex and there is much that we don’t know. The immune system’s network of organs, cells, and molecules reaches into almost every part of the body.
One way to grasp the workings of the immune system is to think of the immune system as a country. Like a country, the immune system has border guards whose duty is to provide protection from outsiders. It has customs officials who check incoming cells and microorganisms to determine whether they should be admitted. If an unwanted invader penetrates the border, the immune system can mount a counterattack with its army of white blood cells. The immune system’s intelligence agency keeps dossiers on undesirable bacteria and viruses so it can recognize and destroy those elements when they arrive. The immune system also has mechanisms for handling civil wars and rebellions. If the immune system is overstimulated, it can harm the body, but the system’s civil guards can quiet revolts and maintain the peace. All the agencies work together to make sure that the immune system is a healthy, well-functioning entity.
Self-Tolerance: Knowing Which Cells Belong in the Body
The central duty of the immune system is to distinguish between what belongs to the body and what doesn’t belong. For this reason, every cell that originates in the body has distinctive molecules—identification papers, so to speak—that mark it as belonging. Immune system cells do not attack cells that have their papers in order. However, all cells that originate outside the body are suspect. Foreign cells have distinctive molecules called epitopes. When the immune system encounters a foreign cell that it recognizes and knows to be harmful, it takes steps to halt the invader. These invaders are known as antigens. An antigen can be a bacterium, virus, microbe, parasite, or toxin. An antigen is any substance that provokes the immune system to act. The ability of the immune system to distinguish between cells that belong to the body and cells that don’t belong to the body is called self-tolerance.
Guarding the Surfaces of the Body
The first line of defense against disease—the border guards, so to speak—is the skin and mucus membranes. The skin wraps the body and creates a boundary between the body and the outside world. It secretes antibacterial substances that kill off most bacteria as soon as they arrive. The mucus membranes protect the nose and mouth against germs. Mucus contains an enzyme called lysozyme that breaks down bacteria before they can do any harm.
Lymphatic System: The Army of the Immune System
The lymphatic system comprises a network of lymph nodes whose purpose is to filter out and drain contaminants and bacterial infections from the body. There are about six hundred lymph nodes, or glands, most of them clustered around the neck, groin, and armpits. The system carries lymph—a fluid composed chiefly of white blood cells called lymphocytes—from the tissues to the bloodstream. As lymph flows through the body, it filters the body of disease. During an examination, doctors often feel the lymph nodes in the neck to see if they are swollen. Swollen lymph nodes mean that the nodes are producing additional white blood cells because the body is fighting an infection.
Cells of the Immune System
The cells of the immune system, to stretch a metaphor a bit farther than perhaps it should be stretched, are like the police. They patrol the different parts of the body and attack invaders or spread information about invaders. The cells that become immune cells originate in the bone marrow, primarily in the legs, from stem cells. From there, the cells can develop into a number of different types. In brief, here are the different kinds of immune cells:
The macrophage, a particularly powerful cell, deserves special attention because it plays an important role in boosting the immune system. What’s more, as you will learn later in this chapter, medicinal mushrooms are known to have a stimulating effect on macrophages.
Macrophages were discovered in the 1880s by Dr. Elie Metchnikoff, a Russian biologist. Noting their size and ability to devour other cells, he created the term macrophage from the Greek macro, which means “big,” and phage, which means “eater.” Metchnikoff used the term phagocytosis to describe the process by which the macrophage destroys the foreign invader.
As soon as a macrophage encounters a foreign organism or substance, it engulfs and destroys it with a barrage of cell-killing enzymes. Macrophages, along with other cells such as dendritic cells, are antigen-presenting and antigen-processing cells, or APCs. These cells present a harmless fraction of the antigen they have just destroyed to T cells so that T cells can learn what the antigen is and be able to recognize and attack it themselves. Next, the macrophage secretes cytokines, the cell messengers that alert the immune system to the presence of an invader. The result is a “chemical frenzy” or “immune cascade” in which natural killer cells and T cells are produced in large numbers to repel invaders. So, besides killing antigens on its own, a macrophage plays a key role in recognizing when the body is being attacked and alerting the body to an attack.
Antibodies and Immunoglobulins
Each type of antibody is programmed to bind to and possibly neutralize a certain kind of antigen. Antibodies are secreted by B cells. When a B cell encounters an antigen with which it is familiar, it produces large plasma cells, and these cells, in turn, produce antibodies in large numbers. The antibodies go out and bind to the antigen. In effect, the B cell makes the prototype antibody for attaching to an antigen, and the plasma cell takes the prototype and creates many antibodies from it.
Antibodies are members of a family of large protein molecules called immunoglobulins. There are nine types of immunoglobulins. Some serve to help other cells in the immune system kill microorganisms. Others activate cells of the immune system, such as B cells. Some kill bacteria. One class, IgE, is involved in the defense against parasites, but because most parasites are under control in the urban population of the United States, IgE is also associated with allergies in most Americans.
The Immune System’s Memory
Like the nervous system, the immune system can build a memory. When T cells and B cells are activated to fight a disease, some become memory cells. These cells store information about the disease and pass it on to the next generation of cells. In this way, the immune system can recognize bacteria and viruses it has confronted before and stop them. Throughout our lives, the immune system adds to its memory of microbes, bacteria, and viruses, and it becomes more competent at fighting disease.
Incidences of cancer are on the rise. We see higher rates of heart disease and diabetes. More people suffer from allergies. According to some, there is a worldwide asthma epidemic. In Australia, for example, two of every five primary school students have been diagnosed with asthma.
Some people read the reports about higher disease rates and conclude that pollutants and toxins are to blame. According to these people, synthetic compounds in the air and water, emulsifiers and preservatives in processed food, and the depletion of the ozone layer have weakened the immune system. These people—and some of them are quite shrill—think that the immune system is under siege. They believe that modern life with its peculiar stresses and environmental challenges has put the immune system on trial and made the body more susceptible to disease.
Rates of disease are rising, but we believe that the cause has less to do with environmental factors and more to do with improvements in medical science. Improvements in medicine, paradoxically, have led to an increase in disease. Advances in medicine have helped push life expectancies past age seventy-five in most industrialized countries. The older you are, however, the weaker your immune system becomes, and the more likely you are to acquire an illness. As the number of older people rises, so do incidences of disease. What’s more, from the point of view of genetics, adults on average have weaker immune systems than they did in the past. In times past, to put it crudely, the natural selection process in the form of diseases such as infectious diarrhea, measles, and whooping cough weeded out children with weak immune systems and unfit genomes. Most of these children died in the first year of life. As adults, the children who would have died in earlier times from a childhood disease are more likely to be ill because their immune systems are weaker. This combination of an older population and a weaker immune system in the average adult has caused the rise in disease rates.
From what we know of records kept in Western Europe and North America (the only regions where reliable records were kept), life expectancy in the mid-eighteenth century was between thirty-five and forty-two years. Cancer was essentially unknown because most cancers occur after the age of fifty. Many diseases were ignored in spite of the efforts of anatomists and anatomo-pathologists who started working during the eighteenth century when the ban on dissection and autopsies was lifted. Tumors were considered accidents of nature. Indeed, the era produced beautifully illustrated medical textbooks with pictures of tumors, and one could see models of tumors in the wax museums of Europe, but tumors were merely a curiosity. Menopause was totally unknown because not enough women reached the age of menopause.
The nineteenth century saw real improvements in medicine. Edward Jenner administered the first immunizations against smallpox around 1800. Joseph Lister developed his antiseptic surgical techniques in 1865. Louis Pasteur identified germs at about the same time. By 1900, these medical discoveries and others pushed life expectancies in industrialized countries to about age fifty-five. Diseases such as cancer and diabetes were still not well known or understood. The dread disease of the nineteenth century, the disease whose name evoked fear and anxiety the way cancer does in our day, was tuberculosis. People still did not live long enough to acquire cancer in great numbers, although the disease did receive attention. Physicians believed, and rightfully so, that cancer was rare in people younger than forty. One physician observed that cancer was most likely to occur in people who live in temperate climates in the “highest state of culture and civilization,” but that it was entirely absent in Native Americans and infrequent in African Americans. We may presume, given the conditions under which they lived in the nineteenth century, that these groups rarely lived long enough to get cancer in significant numbers.
In the past hundred years, life expectancy has jumped in most industrialized countries past seventy-five years of age. Moreover, the natural selection process by which children with weak immune systems died in the first year of life has ended. Is it any wonder that diseases that thrive on a weakened immune system—allergies, cancer, asthma, diabetes, and heart disease—are on the rise? If a polluted environment were the cause of rising rates of disease, incidences of asthma would be decreasing, not increasing, for example, in Los Angeles and Denver. Starting about 1975, those cities embarked on ambitious plans to curb air pollution. They succeeded by every measure in spite of population growth. The air over Denver and Los Angeles has seen a reduction in particulates due to diesel fuel, nitrogen oxide, and sulfur dioxide. Nevertheless, asthma rates have risen in Los Angeles and Denver. They have risen because asthma is an inflammatory disease often associated with allergies and the extra production of 19E, a disease more likely to occur in people who have a weak or compromised immune system. Asthma is brought about by various cells of the immune system that appear to go into overdrive and remain in a chronically activated state. The result is a chronic inflammatory disorder of the airways that results in their narrowing and makes breathing extremely difficult.
The immune system begins developing during the first weeks of gestation. The cell-mediated immunity that is associated with T cells develops in the womb. The fetus has an immune response very, very early in life. When a child is born, he or she has a fully intact natural immune system. The system is stimulated after birth and reaches its peak at the onset of puberty, between age eleven and fifteen (sometimes later if and when children live in a hygienic environment). At that time, the immune system reaches a plateau; starting at age thirty-five or so, it doesn’t work as well. Some parts of the immune system work well, but others are lazy, and others work too well and perhaps cause autoimmune disorders.
After age 50, the immune system experiences a decline. To be blunt, the human body is not supposed to live past that age. Nature, cruel and pitiless, wants you to make room for subsequent generations after your fiftieth birthday. However, advances in medical science, agriculture, and social organization have pushed life expectancies past age seventy-five in some countries.
Diseases of the immune system are more likely to arise when the immune system is underactive or overactive. As we mentioned at the start of this chapter, an optimal immune system is well balanced. It is neither sluggish nor overstimulated. When the immune system is underactive, the body is more likely to get colds, the flu, and even cancer. An overstimulated immune system makes the body more susceptible to autoimmune or allergic disorders such as diabetes, asthma, and allergies. The following pages look at diseases of the immune system so you can get a better idea of how the immune response works.
Autoimmune Diseases
Autoimmune refers to what happens when the immune system attacks itself. Getting back to our metaphor of the immune system as a country, an autoimmune disorder occurs when civil war erupts and members of the army engage in insurrection. In an autoimmune disorder, the immune system has trouble distinguishing which cells rightfully belong in the body and which do not and it mistakenly attacks cells of the body.
Diabetes is an autoimmune disorder. It is caused by abnormally high blood sugar levels. Either the body doesn’t produce insulin or it isn’t able to use insulin effectively. For reasons that are not fully understood, immune-system cells mistakenly attack the beta cells in the pancreas that produce insulin and the result is an autoimmune reaction. Macrophages, the huge white blood cells that attack foreign cells, attack the beta cells, and this inspires the T cells to get into the act. They mark the beta cells as enemies, and soon the entire immune system attacks the beta cells. Now the beta cells cannot regulate the amount of sugar in the bloodstream and the result is a sugar buildup. Several medicinal mushrooms have proven themselves effective against diabetes. These mushrooms have been known to quiet the immune system when it is undergoing an autoimmune reaction.
Lupus, known as systemic lupus erythematosus, or SLE, is another autoimmune disease. Effective treatments are still lacking and the cause is unknown. The disease gets its name from the red patch that often appears on the forehead of sufferers that resembles a V-shape, like the dark patch on the forehead of a wolf (the wolf’s Latin name is lupus). The symptoms vary greatly and can include rashes, inflammation of the fluid membrane surrounding the lungs, arthritis, anemia, rashes, seizures, oral ulcers, and low white blood cell counts. Many lupus patients have signs of fatigue, anxiety, or depression. The disease is treated with immunosuppressants, steroids, and nonsteroidal anti-inflammatory drugs.
An allergy is also a disease involving the immune system’s going into overdrive. Allergies are associated with antibodies of a class called IgE. When someone who is prone to allergies encounters an allergen for the first time, the person’s B cells produce large numbers of antibodies of the type that are designed to counteract the allergen. The antibodies attach themselves to mast cells in the nose, tongue, skin, and gastrointestinal tract. The next time the person encounters the allergen, the mast cells produce chemicals that cause sneezing, watery eyes, and other symptoms of an allergic reaction.
There are practically no allergies to mushrooms. In fact, by being immunoregulators, mushrooms seem to help some people decrease the frequency and the intensity of their allergic reactions. According to some good but limited reports, mushrooms appear to decease the allergic component of the immune response.
Diseases Caused by an Impaired or Sluggish Immune System
Cancer is a complex disease that can affect any organ or system of the body. Causes of the disease include genetic defects, uncontrollable cell growth, and cell damage caused by radiation or toxins. In some respects, cancer is a natural occurrence in the body. According to a recent study, six detectable tumors are produced each year in the body of the average American. If you went to the doctor every day of the year and were probed in the right locations, you would be diagnosed with cancer six times. In most people, however, the immune system eradicates cancerous tumors before they become a health issue.
With approximately 100 million cells dividing in the body per day, some replications are bound to occur in error. One job of the immune system is to identify and destroy these aberrant cell replications before they can divide and pass on their aberrations. When the immune system doesn’t recognize that a dividing cell is aberrant, the cell can continue to grow, and the immune system may not be able to treat it if it grows too large. The result is cancer.
Byway of their polysaccharides, medicinal mushrooms stimulate natural killer cells, cytotoxic T cells, and the macrophages to look for tumor markers on the surface of malignant cells, identify these cells, and destroy them. Medicinal mushrooms help the immune system work better and be more alert, especially at an early age. In effect, medicinal mushrooms tell the cells that patrol the body for abnormalities—the soldiers in the barracks, so to speak—to get up, start circulating, and do their jobs better.
AIDS is caused by the human immunodeficiency virus, or HIY. The virus progressively destroys the body’s lymphocytes, the white blood cells that circulate in the lymph nodes and flush viruses and bacteria from the body. The disease has a particularly damaging effect on the helper T cells that mark antigens in the body so they can be destroyed. Because antigens such as bacteria and parasites are not marked, they are able to infiltrate and damage the body.
When we eat plants and mushrooms, we digest the polysaccharide molecules and they enter our systems. One type of polysaccharide is called beta glucan. Many researchers believe that beta glucan is what gives some mushrooms their medicinal properties. The following pages explain polysaccharides and beta glucan.
Introducing Polysaccharides and Beta Glucan
Mushrooms and plants are composed of polysaccharides, which are long chain molecules constructed from sugar units (poly means “many,” saccharide means “sugar”). How the polysaccharides arrange themselves into structural units and how they bind together determine what compounds they form. For example, cellulose, the cell wall material in plants, represents a particular configuration of polysaccharides. Chitin, the cell wall material in mushrooms (as well as insects, shrimp, and sponges), represents a different configuration.
Beta glucan molecules, or simply beta glucan (or β-glucan), are one configuration of polysaccharide. As you will see, beta glucans are found in abundance in medicinal mushrooms and are one reason why medicinal mushrooms strengthen the immune system. The term beta glucan refers to the way that the sugar units are attached to one another in the polysaccharide chain. Each glucose molecule has six carbons. For that reason, the linkage between the different carbons can occur at any combination of six positions. A polysaccharide in which the molecule at the first position is linked to the next molecule at the third position is called a 1-3 beta glucan. Most beta glucan in mushrooms is of the 1-3 variety and is known to boost the immune system. Plants, by contrast to mushrooms, mostly contain 1-4 beta glucan in which the molecule at the first position is linked to the next molecule at the fourth position.
A beta glucan is a huge molecule. To see how large, consider penicillin, which is one of the largest molecules at 500 or more molecular weight. Compounds found in plants can sometimes reach 45,000 or 50,000 molecular weight. The beta glucan molecules found in mushrooms, however, are typically 1.5 to 2 million molecular weight. Mushroom beta glucan is a whole order of magnitude more complex than other molecules. The size of mushroom beta glucans has a lot to do with their value as immune-system stimulators, although the size and complexity of beta glucan molecules also make it hard for scientists to study precisely why they are so beneficial to the immune system.
One problem with taking beta glucan as a health supplement is that, due to the size of the molecules, beta glucan can be difficult to digest. However, beta glucans are chain molecules. Like any other chain, they can be broken down, and one segment of the chain has all the properties of the other segments. Vitamin C has been known to help the digestive system break down beta glucan.
How Beta Glucan Aids the Immune System
Beta glucan does not in and of itself cure disease. It makes the immune system work better so that diseases can be prevented from attacking the body. No one knows precisely how beta glucan stimulates the immune system. Beta glucan molecules are so large, it is hard for scientists to trace their action in the body. Nevertheless, it appears that beta glucan molecules resemble the molecules found on bacterial cell walls. In effect, beta glucan molecules are phantoms that make the body believe it is being invaded by a bacterium. When macrophages—the giant white blood cells that guard the body against disease—encounter a beta glucan, they believe that they have encountered a bacterium and they attack. This gives a boost to the entire immune system. Immune cells, such as T cells, are put on alert. Levels of immunoglobins (in other words, antibodies) increase. The immune system believes it is under attack and it goes into a state of high alert. It takes all the measures it normally takes when it detects the presence of a virus, bacterium, or tumor cell.
The unique molecular shape of beta glucan permits it to bind to certain receptor cells on the surface of macrophages and other kinds of white blood cells. In effect, the beta glucan molecule puts its key into the macrophage and unlocks it. As a result, free radicals are produced. Free radicals are molecules that have one or more one unpaired electron. As the section entitled “Mushrooms and Free Radicals” explains later in this chapter, free radicals help kill bacteria, viruses, parasites, and malignant cells, although they can also damage normal cells and their production must be controlled.
Within macrophages, beta glucan has also been shown to stimulate the production of cytokines, the cell messengers that tell the immune system when it is being attacked. Cytokines aid macrophages in stopping the growth of and destroying tumors.
To test the health benefits of beta glucan, scientists at the laboratories of Alpha-Beta Technology in Worcester, Massachusetts, incubated beta glucan in blood and examined the results. They discovered that beta glucan indeed caused free radicals to appear in white blood cells. Beta glucan also stimulated the growth of megakaryocyte and myeloid progenitor cells. These types of cells develop into immune cells.
Each mushroom appears to produce its own slightly different type of beta glucan. The length of branching along the glucose chain differs in the beta glucan found in different mushrooms. For that reason, each mushroom stimulates the immune system in a slightly different way. Because each glucose molecule has six carbons, glucan chains that are thousands of units long can join in a nearly infinite number of ways, and the different beta glucan structural arrangements have a similar but slightly different activity in the body.
In the next decade, as scientists focus their attention on the immune-enhancing properties of beta glucan, we are sure to learn more about the different varieties and how they prevent disease. For now, we know that the beta glucans from the maitake mushroom, for example, stimulate the production of T cells. Agaricus blazei, on the other hand, has a very unique 1-6, bonded-chain beta glucan. The mushroom offers almost no T cell stimulation activity, but it stimulates the production of natural killer cells.
The United States Food and Drug Administration (FDA) has granted GRAS (Generally Recognized As Safe) status to beta glucan. It can be extracted from other substances besides mushrooms, notably from algae, oats, wheat, and brewer’s yeast. Medicinal mushrooms, however, offer the greatest variety of beta glucan. What’s more, medicinal mushroom products offer more than just beta glucan. They also offer antibacterial and antiviral compounds.
Beta Glucan Studies
Interest in beta glucan as a health supplement began in the 1940s when scientists working under Dr. Louis Pillemer extracted a crude substance they called Zymosan from the cell walls of yeast. Dr. Pillemer and his colleagues understood that the substance activated the immune system, but they didn’t know how or why. In the 1960s, Nicholas DiLuzio of Mane University succeeded in isolating 1-3 beta glucan as the active component of Zymosan. Wrote Dr. DiLuzio, “The broad spectrum on immunopharmacological activities of glucan includes not only the modification of certain bacterial, fungal, viral, and parasitic infections, but also inhibition of tumor growth.”
In the 1980s, Dr. Joyce Czop of Harvard University unraveled the mystery of how beta glucan stimulates immunity. She observed a 1-3 beta glucan docking to receptor sites on the surface of a macrophage cell and determined that this docking activity stimulated the macrophage to action. She wrote, “Beta glucans are pharmacologic agents that rapidly enhance the host resistance to a variety of biologic insults through mechanisms involving macrophage activation.”
One of the first clinical experiments with beta glucan occurred in 1975 when Dr. Peter Mansell of the National Cancer Institute attempted to see whether beta glucan could aid in the treatment of malignant melanoma, a dangerous form of skin cancer. Dr. Mansell injected beta glucan into the nodules of the skin cancer in nine patients. He wrote that the cancer lesions were “strikingly reduced in as short a period as five days” and, in small regions, “resolution was complete.”
Interestingly, one of the first large-scale tests of beta glucan was conducted on fish. In the 1980s, the Norwegian salmon-farming industry was hit with huge losses due to bacterial infections in the fish. The salmon were fed antibiotics, but the bacteria soon produced resistant strains and the antibiotics proved ineffective. One scientist, Dr. Jan Raa of the University of Norway, decided to try a novel technique. He introduced beta glucan into the food supply, and the infections soon disappeared.
Over the past two decades, the number of scientific studies on beta glucan has been growing steadily (in 1996, there were 144 scientific studies in all). Here are a handful of revealing trials and studies on the immune-enhancing effects of beta glucan:
Beta Glucan and Cholesterol
Beta glucan has a demonstrated ability to lower cholesterol levels. The United States Department of Agriculture (USDA) conducted a study to determine if adding beta glucans to the diet lowers cholesterol levels. Twenty-three volunteers suffering from high cholesterol took part in the study. In the first week, all were put on a diet in which 0.8 percent of their calories came from beta glucans and thirty-five percent came from fat. Starting in the second week, one group of volunteers received an oat extract with one percent beta glucan, and another group received an oat extract with ten percent beta glucan. After three weeks, when the study concluded, cholesterol levels in the group that received the larger amount of beta glucan dropped significantly. Cholesterol levels dropped in the other group as well, but not as dramatically. Researchers are not certain why beta glucan lowers cholesterol levels. One theory is that beta glucan traps bile acids—which were made from cholesterol—and flushes them from the body. As bile acids leave the body, cholesterol does too. Another theory is that beta glucan decreases the production of cholesterol by the liver.
Beta Glucan and Asthma
Asthma is a chronic inflammatory disorder that causes the airways in the lungs and throat to narrow. The narrowing can be caused by pollutants, smoke, pollen, dust, or other stimuli. Five percent of the population of the United States is supposed to suffer from asthma. Interestingly, asthma rates are higher in industrialized countries than developing countries. Some physicians believe that the high rates of asthma in industrialized countries are caused by the relative cleanliness of those countries. These physicians believe that the body, especially in childhood, needs to be exposed to mycobacteria, viruses, and parasites so that it can learn to fight off microbes. People in developing countries, these physicians argue, do not contract asthma as often because their bodies have learned to counteract mycobacteria.
One theory is that beta glucan can help prevent asthma because beta glucan molecules are similar in shape to those of mycobacteria. The theory is that asthma sufferers and people who are susceptible to asthma can use beta glucan as a substitute for mycobacteria. In so doing, they can build up the The cell response that prevents asthma.
Absence of 1-3 Beta Glucan in the Modern Diet
As we have demonstrated, 1-3 beta glucan helps the body build a strong immune system. Beta glucan stimulates the production and activity of T cells, natural killer cells, and macrophages. Some scientists believe that cancer, arthritis, allergies, and other diseases that result from a weakened immune system are on the rise because people are not getting enough 1-3 beta glucan in their diet. Processed foods and so-called fast foods are probably to blame.
As we explained earlier, plants mostly contain 1-4 beta glue an, but plants contain a small amount of 1-3 beta glue an —the kind found in mushrooms—as well. Oats and wheat have the highest 1-3 beta glucan levels. In these grains, as much as two or three percent of the molecules are 1-3 beta glucans. In the past, most people obtained their 1-3 beta glucan from grains such as oats and wheat, but the amount of 1-3 beta glucan in those grains has dropped in recent years. Modern food-processing companies prefer grains with low 1-3 beta glucan levels. These grains contain less fiber. They are easier for people to digest. Animals who eat corn and oats with low levels of 1-3 beta glucan absorb the grains better and do not produce as much dung (a useless byproduct on the modern farm, where chemical instead of natural fertilizers are used). Because modern food-processing companies prefer grains with less fiber (and less 1-3 beta glucan), farmers grow those grains. The result is a loss of 1-3 beta glucan in the modern diet, a loss for which you can compensate by making medicinal mushrooms a part of your diet.
The term adaptogen was coined in the 1940s by a scientist of the defunct Soviet Union named Dr. Nicolai Lazerev. In his studies of wild Siberian ginseng, Dr. Lazerev noticed that the herb had a quieting affect on the nervous system and helped reduce the effects of stress on the body. Dr. Lazerev used the term adaptogen to describe herbs like ginseng that help the body adapt during times of stress. Two colleagues of Dr. Lazerev, I.I. Brekhman and I.V. Dardymov, refined the definition of an adaptogen as follows: “[It] must be innocuous and cause minimal disorders in the physiological functions of an organism, it must have a nonspecific action, and it usually has a normalizing action irrespective of the direction of the pathological state.” In traditional Chinese medicine, adaptogenic herbs and medicines are usually termed tonics. A tonic herb is one that makes the body more resilient and strengthens the body’s natural defenses.
Scientists are discovering that stress engages many different areas of the body: the nervous system, the cardiovascular system, hormone production, and others. The problem, some scientists believe, is that the body’s response to stress was conditioned in prehistoric times when humankind faced acute, short-term, life-threatening stress, not the long-term, persistent stress and anxiety we face today. When the body experiences stress, the adrenal glands secrete hormones, the sympathetic nervous system quickly arouses itself, the heart beats faster, blood pressure rises, and the amount of sugar in the blood increases. Some scientists believe that the body often overreacts to stress. Sustained periods of stress can tax the nervous system and cardiovascular system. They can disrupt hormone production. Long-term stress can lead to cardiovascular disease, fatigue, and depression. The cumulative effect of all this may result in a weakened immune system.
Consider, for example, the effect of increased cortisol levels in the body. To help cope with stress, the adrenal glands produce increased amounts of a hormone called cortisol. Increases in cortisol are normal when faced with a life-threatening situation. For example, the adrenal glands secrete higher levels of cortisol to reduce unnecessary and painful inflammation and thereby heal wounds. However, long-term increased levels of cortisol can cause diabetes and fatigue, as well as weaken the immune system.
Adaptogens are believed to let the adrenal glands recharge. stabilize the body’s hormone production, and help the body control blood sugar levels. Many herbs are considered to have adaptogenic properties, including different varieties of ginseng, astragalus, and licorice root. Three mushrooms described in this book—reishi, shiitake, and maitake—are considered adaptogens.
Many medicinal mushrooms contain terpenoids. Terpenoids help the immune system and the healing process in various ways. Generally speaking, they are good at killing bacteria and viruses. They are anti-infectious agents. Some terpenoids protect the arteries of the heart. Many of them are anti-inflammatory. This means that they prevent the immune system from overreacting.
The word terpenoid comes from the turp in turpentine. Turpentine, made from the resin of pine trees, has been used as an antiseptic for cleaning wounds and cuts since the time of the ancient Greeks. When scientists studying turpentine isolated the substance that gives turpentine its healing power, they coined the word terpenoid to describe the substance. Terpenoids are found throughout nature, not just in turpentine. Like turpentine, many substances and plants that contain terpenoids give off a slightly bitter aromatic odor.
The anti-inflammatory role of terpenoids is especially valuable to the healing process. To see why, consider what happens when you get a cold. The cold virus causes the nose and throat to swell and redness to appear around the nostrils and nose. The swelling and the redness are part of the inflammatory process due to reactions of the immune system. The immune system sends white blood cells to attack the infection, and as more white blood cells arrive, the area around the infection starts swelling. Sometimes, however, there is too much swelling and an inflammatory reaction occurs. In the case of a cold, the inflammatory process exceeds it goals and creates an inflammation that is useless for the patient. The nose and throat constrict and breathing becomes difficult.
An inflammatory reaction in the arteries can have especially bad consequences. In this case, the wall of the artery can swell and encumber the flow of blood. Many physicians believe that heart disease is caused initially by an inflammatory reaction in the arteries. This is why many doctors recommend aspirin to patients. Aspirin, like the terpenoids, is anti-inflammatory. Steroids such as cortisone are also anti-inflammatory. The inflammation that accompanies an infection is healthy as long as it is kept under control. To control inflammation, if necessary, we can use anti-inflammatory substances, but many of these substances also block the benefits of the immune response. Cortisone, for example, prevents inflammation but also allows germs to proliferate.
The beauty of terpenoids is that they temper the action of the immune system’s response to infections. They are anti-inflammatory, but not to the extent that they prevent the white blood cells from doing their job. Terpenoids respect the natural healing process while protecting against inflammation. They stimulate the body’s immune defenses, kill germs, prevent inflammation, and give the patient a degree of comfort. By the way, terpenoids are some of the oldest medications. To cure the common cold, people have been inhaling the fresh resin of pine trees and eucalyptus leaves for many, many years. Pine tree resin and eucalyptus leaves both contain terpenoids.
You may be interested to know that there are ten thousand times more germs in your gastrointestinal tract than there are cells in your body. By some estimates, bacteria in the large intestine account for ninety-five percent of all cells in the body. Most people carry around three to four pounds of bacteria in their gastrointestinal tract. These germs amount to a sort of ecosystem that is different in the body of each individual. Some of the bacteria are good and some may be bad. Bifido bacteria, for example, prevent diarrhea and constipation. Pathogenic E. coli, on the other hand, causes severe cramps, diarrhea, and sometimes death. Due to diet, viral infections, bacterial infections, or the use of antibiotics, normal bacteria in the intestinal tract can be depleted. When this happens, pathogenic bacteria may predominate and cause an illness.
Prebiotics are substances that help the good bacteria in the intestinal tract. They are a sort of intestinal fertilizer in that they promote the growth of beneficial bacteria. Prebiotics feed microorganisms that are helpful to the intestinal tract, and they kill microorganisms that are not helpful. They produce vitamins of the B family. They assist the body in absorbing minerals such as calcium and magnesium. Prebiotics aid the immune system by killing pathogens. Some researchers believe that they also lower blood cholesterol, prevent diarrhea, and help fend off colon cancer.
High-fiber foods such as mushrooms are prebiotics. These foods help bacteria in the large intestine to breed in a balanced, harmonious way. Mushrooms are a class above many other prebiotics because they contain terpenoids that are antimicrobial but don’t affect the good germs in the intestinal tract. Mushrooms also stimulate M cells in the lining of the intestine. These cells, similar to antigen-presenting and APCs, kill antigens and microbes but also pass along samples of the antigens and microbes they have killed to the immune system. In this way, the immune system is awakened and put on alert for invaders.
By the way, be careful not to confuse prebiotics with probiotics. A probiotic is a live bacterial culture like that found in yogurt and other fermented dairy products. Probiotics are also good for the intestinal tract. They provide bacteria that the intestinal tract needs to stay healthy.
A free radical is an atom of oxygen whose composition is the same as that of bleach. As everyone knows, bleach is used in the household to kill bacteria—and it is used the same way in the body. To kill bacteria, viruses, parasites, and malignant cells, white blood cells and macrophages release free radicals. However, if these free radicals proliferate too freely, they may kill normal cells. As a result, body tissue dies—in muscles, bones, skin, and elsewhere—and the body ages faster.
In biochemistry, substances called antioxidants are capable to a certain extent of reversing the damage that free radicals do to body tissue. Mushrooms are antioxidants. Perhaps the three most well-known antioxidants are vitamin C, vitamin E, and beta-carotene. Taking antioxidants helps reduce unnecessary free radicals. By bringing the number of free radicals to a normal, more acceptable level, antioxidants control the aging process.
However, some antioxidants can have a harmful effect on the body. In a recent study conducted in Finland, beta-carotene supplements were given to smokers who had contracted lung cancer. Smoking encourages the production of free radicals in the lungs. The body, to kill the toxins that smoking brings in, produces free radicals, but these free radicals can kill normal cells and thereby kill normal tissue as well. The researchers in Finland wanted to see if taking the synthetic antioxidant beta-carotene would curb the production of free radicals in the smokers’ lungs. They were puzzled to discover that beta-carotene had the opposite effect: more free radicals were seen in the smokers’ lungs. This study and others like it seem to show that beta-carotene actually encourages the production of free radicals in the stressed parts of the body in which there is already an excess of free radicals. In other words, taking the antioxidant beta-carotene can be harmful in some instances.
Antioxidants can also be harmful if you exceed the optimal dosage. Studies indicate, for example, that taking too much vitamin C actually encourages unnecessary free radicals to be released in the body. This is why the National Academy of Sciences recommends taking no more than one gram per day of vitamin C.
The good news for people who make mushrooms a part of their diet is that it you never run the risk of stimulating the unnecessary production of free radicals. Mushrooms do not produce excess free radicals anywhere in the body. As to exceeding the optimal dosage, it is hard to do that with mushrooms. You will experience indigestion and bloating long before you reach the optimal dose.
The liver is the body’s second largest organ (the skin is its largest). The job of the liver is to detoxify the body. The liver is the body’s chemical plant. It manufactures cholesterol, which every membrane of every cell needs. The liver produces approximately twenty proteins, including antibodies and the proteins that are involved in the inflammatory process by which the immune system attacks infections. These proteins ensure that the body fights infections without going to excessive lengths. If the liver doesn’t function well, the inflammatory process is impaired.
It appears that some substances in mushrooms have a protective effect on the liver. Mushrooms have been used to treat a variety of liver disorders, including hepatitis, a disease that infects 350 million people, according to the World Heath Organization. In a study of 355 cases of hepatitis B treated with the Wulingdan pill, which includes the fruit-body of the reishi mushroom (Chapter Three describes reishi), 92.4 percent of the subjects showed positive results. Lentinan, the drug derived from Lentinula edodes (the shiitake mushroom described in Chapter Ten), has shown favorable results in treating chronic persistent hepatitis and viral hepatitis B. Trametes versicolor (the subject of Chapter Eight) is sometimes prescribed for chronic active hepatitis and hepatitis B.
To better understand the value of maintaining a strong immune system, consider how antibiotics such as penicillin have been used and abused by doctors and their patients. When antibiotics were introduced in the 1940S, they were presented to the public as a kind of miracle drug. And antibiotics have performed many miracles. Death by infectious bacterial disease is five percent of what it was a hundred years ago. In 1900, hospitals were very dangerous places. If bacteria entered and infected a surgical incision, the patient often died.
The trouble with antibiotics, however, is that bacteria find ways to fight and resist them. Some bacteria are very resilient. As they fight off antibiotics, they develop into new strains—strains that are sometimes resistant to antibiotics. The dilemma is caused by natural selection. The antibiotic kills most bacteria, but the strongest survive and hand down their survival characteristics to the next generation. Some bacteria train plasmids to convey the resistance to other bacterial species. In effect, antibiotics have created new diseases.
Consider the bacterium Streptococcus pneumoniae. The bacterium causes pneumonia and meningitis. Each year, it causes half a million cases of pneumonia and an estimated seven to ten million ear infections in children. Doctors used to be able to treat the bacteria with penicillin, but some strains of the bacteria have become resistant to antibiotics.
“This super-bacteria explosion is a public health crisis of the first order,” reports Dr. Jack Dillenberg, Director of the Arizona Department of Health Services. “If left unchecked, we face potentially devastating consequences, including widespread sickness and death from once-curable diseases.”
Ironically, doctors are forced to prescribe antibiotics more frequently as the drugs become less potent. By some estimates, 190 million doses of antibiotics are administered each day in hospitals—that’s right, each day. Annually, doctors prescribe more than 130 million courses—doses administered over a few days or weeks—to their out-of-hospital patients. The numbers are alarming. They underline the importance of preventing disease by maintaining a healthy immune system. Take the following precautions with antibiotics to make sure you use them wisely:
Some of the mushrooms that are described in this book can be purchased in gourmet markets and supermarkets. That begs the question, “Can culinary mushrooms provide the same health benefits as medicinal mushroom products?”
Culinary mushrooms are an aid to health. They appear to be a good source of B vitamins, iron, niacin, riboflavin, thiamine, and ascorbic acid. By proportion to weight, mushrooms are high in polyunsaturated fats. Cultivated varieties contain large amounts of carbohydrates and fiber. On a dry-weight basis, a mushroom is high in protein, and mushroom proteins contain essential amino acids.
The relationship between good health and a diet rich in mushrooms came to the attention of modern science when health researchers noticed that people who eat mushrooms seem to be healthier than other people. In Japan, for example, scientists discovered fewer incidences of cancer in shiitake-growing regions (shiitake is described in Chapter Ten of this book). Assuming that people who lived in these regions ate the shiitake mushroom often, scientists wanted to see whether shiitake had anticancer properties. They ran many tests on shiitake. In so doing, they discovered and introduced Lentinan, the third most widely prescribed anticancer drug in the world.
Some mushrooms are better than others. Shiitake, for example, stimulates the immune system about a hundred times more than the common white button mushroom does. Maitake (described in Chapter Six of this book) does much more to aid the immune system than do morels, portobellos, chanterelles, or any other culinary mushroom. Still, all mushrooms are excellent for your heath. The difference between culinary mushrooms and medicinal mushrooms is that medicinal mushrooms are a class above their culinary cousins.
Taking a mushroom product in capsule or powder form has distinct advantages because most mushroom products are made from the mycelium, the feeding body of the mushroom that grows underground. Mycelium is a potent substance. You could say that mycelium is nature’s way of concentrating the beneficial compounds of mushrooms. When you buy a culinary mushroom, however, you buy the fruit-body. Fruit-bodies do not always contain the potent concentrations of polysaccharides that are found in mycelium. (Mycologists are currently perfecting cultivation techniques whereby the fruit-body of mushrooms can contain potent concentrations of polysaccharides.)
What’s more, medicinal mushroom products are more hygienic. The mycelium powder is subjected to autoclave sterilization before it is pressed into pills or poured into capsules. Taking medicinal mushrooms in pills or capsules is easier on the digestive system, too. The mycelium finds its way into the body faster than the fruit-bodies of mushrooms do.
Because nonorganic, storebought mushrooms are often sprayed with pesticides, eating them regularly may actually be harmful. For that reason, we recommend buying culinary mushrooms at health food stores and other places where organic products are sold.