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| Acknowledgments | p. vii |
| Preface | p. ix |
| Introduction: The Immunity-Pleasure Connection: What It Is, How It Works--And How It Can Work for You | p. 1 |
| Say Hello to Your Immune System: Your Body's Department of Defense | p. 9 |
| Getting Connected ... with Enhanced Immunity | p. 29 |
| It's All in Your Head: How Attitude, Disposition, and Mood Affect Your Immunity | p. 31 |
| Getting Connected ... with a More Positive Attitude | p. 55 |
| The Stress Mess: Fight, Flight, and the Immunity-Pleasure Connection | p. 61 |
| Getting Connected ... with Less Stress | p. 81 |
| Music Soothes the Savage Breast: But Can It Cure the Common Cold? | p. 83 |
| Getting Connected ... with Music | p. 98 |
| The Pleasure of Touch: Love, Sex, and Social Support | p. 103 |
| Getting Connected ... with Touch | p. 119 |
| In Praise of Pets: Your Immune System's Best Friend | p. 121 |
| Getting Connected ... with Animal Instincts | p. 135 |
| Humor: It Really Is the Best Medicine | p. 141 |
| Getting Connected ... with Humor | p. 155 |
| Light, Sight, and Insight: See the Light and Keep the Faith | p. 157 |
| Getting Connected ... with Light, Both In and Around You | p. 164 |
| Pleasure: The Final Frontier: Where Do We Go from Here? | p. 165 |
| Glossary | p. 187 |
| References | p. 192 |
| Index | p. 201 |
| Table of Contents provided by Ingram. All Rights Reserved. |
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Chapter One
Say Hello to Your
Immune System
Your Body's Department
of Defense
Winning isn't everything. It's the only thing. --Vince Lombardi, former Green Bay Packers coach
If you could put under a microscope all the food you eat, the water you drink, the air you breathe, and everything that your hands and body touch, you'd be so shocked, scared, repulsed, and disgusted that you'd want to live in a disinfected, impenetrable bubble. The sheer number of bugs, germs, microorganisms, and other nasty substances looking to set up house inside your body is astounding. They're everywhere. Their efforts are unrelenting, and you can't escape them.
Bacteria, viruses, cancer-encouraging chemicals, fungi, parasites--they all want you, or at least a piece of you. Many are harmless, but others can drain the life right out of you. (All of them are known collectively as antigens. Those that can make us ill are called pathogens. See "Know Your Enemy" on page 22.) To protect your body, nature developed a surefire strategy: Develop an internal defense system in which anything that doesn't naturally belong in the body will be identified, attacked, and hopefully destroyed.
Welcome to your immune system, a 24-hour-a-day operation designed solely to keep you healthy and alive. How well it works is another matter entirely. It's composed of obscure substances, intricate interrelationships, contradictions, and other technicalities. The immune system certainly is complicated, but a basic understanding of how it functions is fundamental to grasping why the pleasurable things in life preserve your health.
The War on Bugs: How the Immune System Operates
The immune system is a complex network of cells and organs. The B-cell system, consisting largely of a handful of constantly circulating antibodies called immunoglobulins, comprises your humoral immunity. The various T cells are part of what's known as cellular immunity. The organs that generate these fluids and cells include bone marrow; the thymus, which is located in the front of your chest cavity; the lymph nodes, found in your neck, under your arms, and elsewhere in your upper trunk; and a coalition called mucosal-associated lymphoid tissue (MALT), which consists of your tonsils, adenoids, appendix, and Peyer's patches in the intestines.
How does it all work? Consider this military metaphor: Aerial reconnaissance detects an enemy advance on a strategically valuable piece of land and radios an alert to headquarters. Headquarters signals a crack platoon of roving sentries on the perimeter of the territory to be ready for battle. Despite their often-accurate aim in picking off and halting intruders, a particularly crafty and diligent enemy cadre manages to penetrate this initial defensive line. The sentries signal gung-ho guards from other stationed squads for further assistance. These infantrymen do what they can to beat back the attack but are forced to call for more help. Soon, other ruthless warriors, some with bayonets, charge in and stab or otherwise kill the trespassers. At the same time, other units, sensing trouble, may have already joined the fray in helping to win one for our side.
The battlefield metaphor may be a cliché in describing how the immune system functions, but it's accurate on several levels. Whether on the front line or inside the body, the goal remains the same: Kill and eliminate the enemy. The stakes are the same, too: Lose the war, and the consequences could very well be deadly. Each of the military players in the muddy, bloody battlefield analogy above has an immune system counterpart with similar duties.
Inspecting the Troops
Each part of the immune system has its own separate functions, but all interact with one another via chemical and neural signals in an intricate chain of command and communication that involves cells, enzymes, hormones, and brain chemicals.
Humoral immunity. The fluid-based humoral immune system, utilizing the bloodstream and all mucosal tissue secretions, is comprised of antibodies, the most prevalent of which is immunoglobulin A (IgA). It represents your body's initial defensive counterattack when an antigen attempts to invade. It's the perimeter-patrolling sentinel that's always on alert and ready to halt any intruder immediately upon detection. Except for a tiny two-tenths of one percent of us, everyone is born with IgA and so-called innate immunity. (Another kind of internal defense, called acquired immunity, develops depending on our individual unique exposures to various antigens.)
Cellular immunity. These various warriors, white blood cells housed mostly in bone marrow and the thymus, both communicate and eradicate. They include the radio reconnaissance flyers, the commanders at headquarters who notify the humoral sentinels, and the killers that help deliver the final blow against the enemy.
The reticuloendothelial system (RES). If the roaming antibody sentinels don't immediately stop the invasion, these specialized sentinels, stationed at specific strategic points deeper within the defensive perimeter, take aim and fire. RES is comprised of all the lymphocytes produced by the lymph nodes, the spleen, and MALT, plus certain white blood cells (monocytes and macrophages) manufactured in bone marrow. These guards will try to stop anything that gets past the initial sentries along the outer perimeter.
Nonspecific effector system. More backup killers deeper in the territory, these white blood cells, organized into units called monocytes, macrophages, neutrophils, and natural killer cells, also charge out of bone marrow and into the bloodstream. They act on intuition, attacking whenever they sense danger.
Complement. These ruthless proteins and enzymes, called up from the humoral barracks, are specialized killers armed with the cellular equivalent of bayonets. They charge in and quite literally poke a hole in the infectious invader's cell membrane, killing it.
Humoral Immunity: No Laughing Matter
Except for when you suffer a laceration, the only real way for a microorganism to invade the body and threaten your health is through soft, penetrable, moist, mucosal areas--the eyes, nose, mouth, genital openings, and rectum. It first must pass through the very outermost layer of mucus (the mucosal lumen), then attempt to penetrate the mucosal epithelium before entering tissue cells and the bloodstream. This puts the fluid-based humoral immune system on the front line and immunoglobulins in leading roles as the body's initial defenders.
The onus falls heavily on IgA. It's the star player here. Though also found in the bloodstream, IgA is most heavily concentrated in the fluids of our most vulnerable places: tears, mucus, saliva, and vaginal and prostatic secretions. It also appears in breast milk. Get comfortable with this crucially important immune substance. We'll turn our attention to it frequently throughout the book. It not only combats illness but it also deters illness from starting in the first place. When a foreign substance is first detected, IgA rushes in, binds to it, and prevents it from further entering the body. If the antigen somehow evades this first defensive line, IgA signals other immune system phagocytes to step in and literally devour the intruder. A phagocyte is any cell that engulfs and enzymatically degrades an intruder. (The term phagocyte comes from the Greek word phagein , meaning "to eat." Phagocytosis is the process by which cells from other immune subsystems consume foreign cells.)
A quartet of other immunoglobulins also exists. They're present in far smaller concentrations (we have more IgA than the other four combined) and possess limited, specific duties. Immunoglobulin M (IgM), for instance, works in the bloodstream and is the first immunoglobulin that appears after antigen exposure. It binds to any invading antigens and signals for help from other immune components. Its appearance is quite brief, though, and it soon cedes responsibility for longer-term protection to immunoglobulin G (IgG). The primary duty of immunoglobulin E (IgE) is to trigger the production of histamine (and the resulting sniffling, sneezing, wheezing, and tearing) during an allergic reaction. It also participates in the destruction of parasites. The functions of immunoglobulin D (IgD), unfortunately, are largely unknown.
Cellular Immunity: When the Going Gets Tough
From where do IgA and the other immunoglobulins come? How are they deployed for infection-protection jobs? For answers, we need to step out of the saliva and mucus and jump into the bones and bloodstream.
The two major components of the cellular immune system, B lymphocytes and T lymphocytes (for the sake of simplicity, we'll call them B cells and T cells), are white blood cells manufactured in bone marrow. B cells stay there to mature before being deployed, while T cells migrate to the thymus to grow. Generally, both types of lymphocytes play roles in detecting invaders, maintaining a sort of institutional memory of all intruders ever encountered and developing the immune system's ability to both specialize and diversify in eradicating any imaginable outsider.
B Cells: Transforming, Remembering
B lymphocytes work mostly outside the body's other cells and identify bacteria. When an unknown intruder breaks down the door, helper T cells ring the bell and wake up B cells. Once the alarm goes off, B cells release themselves rapidly into the bloodstream and signal IgA, IgD, IgE, IgG, and IgM antibodies throughout our mucosal linings and the blood. The immunoglobulins then bind themselves to the intruder and, if necessary, emit an SOS to other immune system troops.
Like elephants, B cells never forget. They carry most of the immune system's institutional memory of previous engagements. When an antigen is encountered and a specific antibody is created to destroy it, B cells house the information and instinctively know what to do every other time that specific intruder dares to cross the threshold. As opposed to the general, all-purpose innate immunity with which each of us enters the world, this specialization is known as acquired immunity. All of us acquire our own unique immune arsenals depending on our different encounters with the enemy world. The concept of inoculating us against diseases is based on deliberately introducing a harmless, "innocuous" amount of a pathogen precisely so that B cells can react, learn, and remember how to produce antibodies effective enough to fight it. Thank B cells and acquired immunity for the success of Jonas Salk's polio shot and all of our other vaccines.
T Cells: Helping, Killing
Working primarily inside our other cells, T cells are charged with discriminating between the body's own cells and anything that might be alien. They also identify the presence of a virus and note any changes in the shape of our cells that might signal the development of cancer. Two basic types of these lymphocytes develop during the maturation stage in the thymus gland: cytotoxic T cells, which are out-and-out killers that engage in phagocytosis, and helper T cells, which carry the phagocytes to infection sites and provoke inflammation (hence the swelling that we get around a cut). These T cells also are responsible for alerting B cells to step into the intruder-stopping fray.
During the maturation process, both B cells and T cells are twice inspected by other cells to guarantee that they function correctly and can properly distinguish between the body's own cells and any other foreign matter. For T cells, this inspection stage is especially crucial. Any slipup that allows abnormal T cells into the ranks spells big trouble--namely, an autoimmune disorder. T cells that don't know the difference between an invader and your body's own naturally occurring cells are going to wreak havoc on your health.
Those T cells that pass initial inspection become part of our genes by binding to a segment of DNA called the major histocompatability complex (MHC). With more than 100 subclasses and permutations, they then become either permanent parts of our every cell or immune system specialists. The two most important things to keep in mind are CD4 T cells and CD8 T cells. CD4 cells are helper T cells that promote inflammation; CD8 cells are cytotoxic T cells that kill and sometimes rein in and suppress immune system activity.
The RES-t of the Story
Out of both the lymphatic system and bone marrow come the monocytes and macrophages that comprise RES. Wherever an infection arises, monocytes are generated in large numbers, and they transform themselves into macrophages that circulate throughout the body looking for something to destroy. The name of these roving sentries means "big eaters." They literally engulf and consume antigens. Other specialized white blood cells that live to eat belong to the nonspecific effector system, which, besides monocytes and macrophages, includes monocytes, neutrophils, and natural killer cells (NK cells). They remain on continuous, nonstop search-and-destroy missions throughout the body. Rounding out your internal armed forces are the serum proteins of complement. These fierce, merciless assassins latch on to antigens and release enzymes that poke fatal holes in the intruders' cell membranes. Complement proteins also present antigens to phagocytes, often when IgA is involved.
Cytokines: How the Mind Practices Medicine
The choreography required to present this dance against disease is mind-boggling. Proteins, enzymes, hormones, brain neurotransmitters, and other cells communicate with one another through an elaborate chemical and neural network. The fact of the matter is that the chemical changes that occur when we are sick often are the same chemical movements that occur when we are stressed, depressed, or otherwise emotionally low. This is the basis for our proposition that mood, disposition, mental state, and degree of pleasure in one's life exert a profound impact on our ability to remain free of illness.
The great facilitators here, the main molecules that activate, tone down, and otherwise regulate immune activity, are called cytokines. These polypeptide hormones, as they're called, come in a number of varieties: interferon, transformational growth factor (TGF), some 18 different interleukins, and several types of tumor necrosis factor (TNF). Whenever a pathogen or other stressor strikes, cytokines appear on the scene to jump-start the immune system, promote inflammation, and initiate the "acute phase response" of sickness. The so-called pro-inflammatory cytokines (including interleukin-1, interleukin-6, and TNF) are particularly important because of their prominent presence in illness and other disorders. Interleukin-1, for example, helps generate a fever and involves itself in the release of prostaglandin E2, which contributes to controlling pain. It also regulates activity in the hypothalamic part of the brain that governs a whole host of biological and psychological functions.
Interleukin-6, another pro-inflammatory cytokine, plays key roles in telling B cells to get to work generating antibodies, and in helping to make interleukin-1 much more potent in carrying out its various duties. It also shows up when we are ill, when we are under a lot of stress, and when we are depressed. Another factor is interleukin-2, which, along with interleukin-1 and interleukin-6, shows up not only among people with an infection but among people with schizophrenia (see "The `New' Infectious Diseases" on page 25). TNF contributes to generating a fever, and it enhances the secretion of stress-associated catecholamines. Interestingly enough, TNF's presence also is associated with memory and attention.
Disease and Disposition
Note the correlation between the presence of cytokines and emotional state. Cytokines show up not only when we are physically sick but also when we are not well psychologically. This simple fact lays the foundation for the Immunity-Pleasure Connection and much of mind-body medicine.
Because of pro-inflammatory cytokines, the symptoms of having a bad cold and being depressed are similar (see "Flu or Blue?"). What this means is that in the presence of either a pathogen or severe emotional stress, the body reacts in virtually the same way. It means not only that stress can make you ill but also that, via cytokines and pathogens, your immune system can stress you out and affect you psychologically.
Understand that cytokines, in and of themselves, are not bad. On the contrary, they trigger immune activity and coordinate the show when we are physically sick. They become problematic, however, when secreted in overabundance, typically because of an immune system glitch instigated by emotional stress and strain.
For the moment, consider how stress facilitates a pathogen's ability to defeat our immune defenses. For instance, stress hormones change both the number and distribution of various immune cells, reducing resistance to an infection; drugs that suppress stress hormones can strengthen immune resistance. Stress alters the permeability of mucosal linings, giving pathogens easier entry into the body, the bloodstream, and the brain.
It's one thing to say that you can think yourself sick and make other assumptions about psychological influences on health. It's quite another thing to be able to document, thanks to the advent of psychoneuroimmunology, the physiological basis for such claims. Why would stress and a pathogen force the body to react in almost identical ways? What's the common denominator? In brief, from the immune system's perspective, the common denominator is a threat to good health and survival. From the earliest stages of mankind, the greatest threat to survival has come from microorganisms. That's how the immune system came into being, and the stress response may have evolved from that physical survival mechanism. Faced with any harrowing life-or-death situation, it's no wonder that the immune system would become involved.
The Internal Failure
With a basic understanding under our belts of how the immune system functions, let's turn to its failure to keep us healthy. Illness and disease occur for two reasons: The immune system is either too weak or otherwise impaired, or the strength or sheer numbers of certain pathogens simply overpowers it. The weakness and impairment could stem from either physical or psychological factors or a combination of both. The overwhelming opposition also could emerge from a combination of physical and psychological liabilities.
A discussion of diseases with which the immune system must cope could go on endlessly. Here are a few categories particularly susceptible to such factors as stress and the presence (or absence) of pleasure.
Autoimmune Diseases: The Enemy Within
"We have met the enemy and he is us," the immortal Walt Kelly wrote in his often scathing political parody comic strip Pogo . That pretty much sums up what's going on inside the bodies of people with an autoimmune disease, such as rheumatoid arthritis, lupus, multiple sclerosis, psoriasis, and ulcerative colitis.
If you have an autoimmune disease, you have an immune system that has gone awry and sees certain cells in your own body as foreign invaders that must be eradicated. Almost any organ or system in the body can be affected by this friendly fire. In multiple sclerosis, for example, the immune system thinks that the protective covering over your nerves is a foreign invader. In rheumatoid arthritis, it thinks that your joint cartilage is the bad guy. Addison's disease, Grave's disease, myasthenia gravis, pernicious anemia, rheumatic fever, scleroderma, type 1 diabetes--all are autoimmune disorders.
No one knows precisely or entirely why autoimmune disorders exist, why the presence of naturally occurring cells triggers the immune system to attack, or why the immune system can't distinguish between desired, needed, necessary body cells and unwanted, deleterious invader cells. Something goes horribly wrong in the body's "self code," a unique group of antigens called human leukocyte group A (HLA) that's present in almost every cell and determined by the major histocompatability complex (MHC), whose job it is to transport all things that shouldn't be there (nonself) to the cellular surface for detection and eradication by our immune armies. In an autoimmune disorder, immune cells, primarily T cells, in the MHC fail to distinguish between external invading cells and instead bind to natural self cells, setting off an immune response that clobbers the self cells. The glitch can arise in several ways.
(Continues...)
Excerpted from FEELING GOOD IS GOOD FOR YOU by Carl J. Charnetski & Francis X. Brennan. Copyright © 2001 by Carl J. Charnetski, Ph.D., and Francis X. Brennan, Ph.D.. Excerpted by permission. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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