We have immunoglobulin A in our saliva, for example, to help kill invaders as they enter our mouths. We have many different immunoglobulins in our lungs, our intestines, our tears, etc. — in our points of vulnerability — the places where an invader can invade.
At those points, we have immune defenses, guard posts, forts, standing guards. Our lives are at stake and the immune system that has evolved is amazing. The benefit of each advance in the immune system all along our billions of years of evolution were enormous: The ultimate benefit — life or death.
We have T-cells that circulate in the blood and when they recognize an invader they have fought before, the measles or a flu virus for example, they reproduce the antibody for that invader and overwhelm it to kill it off.
When a virus invades your body, it's always a race between your T-cells and the invader. Whichever one can multiply fastest wins. You are invaded fairly often, but if your T-cells reproduce faster than the invader, you never even know the war went on. You won. You didn't get sick. But if your T-cells are sluggish, if they don't reproduce fast enough, the invaders multiply too quickly and overwhelm your defenses, and then backup defenses take over: Fever, excess mucous, whatever tools your immune system can muster to destroy the invader and prevent your own death.
Another battalion in your immune system is natural killer cells (NK cells). They cruise through your blood looking for anything foreign, like cancer cells, and kill it off. Your NK cells are more effective under certain conditions than others.
In one study, the researchers measured the level of pessimism, cynicism and defeatism (the deadly triad) in a group of elderly people and also once a year took blood samples to check the activity level of their immune system. The immune system was less vigorous and less effective in those with the highest measure of the deadly triad. Pessimism is bad for your immune system. Pessimism weakens your defenses against disease.
In another study, researchers looked at what might happen if people learned to think less pessimistically (which you can do here). They divided cancer patients into two groups. Both groups received standard medical care, and one group also received training in thinking less pessimistically once a week for twelve weeks, and also learned some relaxation techniques.
Taking blood samples, the researchers measured the NK cell activity. It was dramatically higher in the people trained to think differently.
In a study I mentioned in my book, Self-Help Stuff That Works, people were tested for their level of pessimism, cynicism, and defeatism. Then they were given some health-related information to study on health topics (like cancer, for example). Here's an interesting finding that really ought to be obvious: The most pessimistic spent less time studying the information and remembered less of it. It ought to be obvious but it was surprising to me when I first read about it, and it's surprising to a lot of people (especially pessimists).
But if you think about it, the outcome of the study makes perfect sense. Pessimism of course makes you less inclined to believe you can do anything to successfully change the course of events. And if you assume you can't do anything about preventing cancer, for example, you're not going to be very motivated to learn anything about it, are you? By assuming you're helpless, you become more of a victim.
What I like about this study is it counters what seems to be a common belief negative people have about optimists. They believe it is a form of sticking your head in the sand and ignoring reality. How else, the pessimists ask, could you avoid being pessimistic, cynical and defeatist? But this study shows that it is actually the people infected with pessimism who are avoiding reality. People who haven't had their strength drained by pessimism know that their own actions have an impact on the world. They know they aren't helpless. They know they have an influence on the outcome of events, so they are more open to information that can help them influence those events.
Because they get more information and they don't make themselves feel defeated, optimistic people are more likely to take action like eating better, exercising, getting checkups at the doctor. A pessimist is less inclined to take those kinds of actions because they feel it won't make much difference. And their lack of positive action makes them statistically more likely to die prematurely.
An optimist (and here I'm using the word in the scientific sense, which really has nothing to do with looking on the bright side or saying nice things to yourself; read more about scientific optimism) might say, "I can quit smoking." And if they try once and fail, they wouldn't give up. They aren't defeated so easily. They'll try again.
A pessimist would be less likely to try in the first place because they explain events in more defeatist ways. "I can't help it. Nicotine has me completely addicted." But if they try anyway but fail, their explanation will not motivate them to try again: "I guess I just can't do it." They are more likely to accept their fate and die prematurely.
In a study of cancer patients, those who thought most pessimistically had the highest death rates, even though they weren't any more diseased when the study began.
Here's another interesting study. Researchers from California and Finland teamed up to ask 2400 men how much they agreed with these two statements:
1. The future seems to me to be hopeless, and I can't believe that things are changing for the better.
2. I feel that it is impossible to reach the goals I would like to strive for.
Clearly this simple questionnaire measures how thoroughly the pessimism has infected the subject's mind has done its work.
Six years later, the ones who answered with pessimism, cynicism and defeatism were two to three times more likely to have heart attacks, develop cancer, or die of any cause.
Researchers are amazingly creative. Some people collect stamps. I collect studies. I love the way researchers go about discovering how things work. Here's another good one. Researchers in Texas tested 2300 people over the age of 65 for the following:
1. Hopefulness about the future.
2. How much they enjoyed life.
4. Their average walking speed.
5. Their happiness level at the time.
Two years later, the researchers followed up on these people. Using these measurements of emotional health, they found that the least pessimistic participants were:
1. Half as likely to have trouble with their daily activities.
2. Were twice as likely to be alive.
3. Had faster average walking speeds.
And these results were independent of their sex, weight, education level, or how much they drank or smoked.
In a Carnegie Mellon University study, researchers gave a cold virus using a nasal spray to 400 volunteers. They found that the most stressed out were twice as likely to catch the cold. Pessimistic, cynical, defeated ways of thinking make mildly stressful situation into more intensely stressful events, and as their actions ensue from their thoughts, they make things get even more stressful (by snapping at people, for example, causing people to snap back). The stress and the cortisol it produces then impairs the immune system.
Another great study was done by the Mayo Clinic. This one followed 800 people for 35 years. Every ten point difference in their level of pessimism increased their chances of dying from any cause 19 percent.
cortisol: the stress hormone
When you undergo stress, your body responds by pumping cortisol into your blood stream. Scientists all over the world have shown how cortisol influences the immune system, sometimes quite directly. For example, college students volunteered to have their mouths injured once during their summer vacation, and once again three days before the first test of a new semester. Cortisol levels are lower during summer vacation and higher right before exams.
The wound given in the mouth was very exact and measured carefully. Then the researchers measured a wound-healing substance in the blood and measured how long it took the wounds to heal. The ability to heal a wound is another of the immune system's line of defense.
During vacation, the wounds healed, on average, in eight days. During the exams, the wounds took eleven days. During the exams, the amount of the wound-healing substance in the blood dropped a whopping 68%.
Psychological stress is one of the side-effects of pessimism. And stress alters the level of certain hormones, like cortisol. These changes in hormones then alter the synthesis of other compounds. For example, cytokines are a compound that help regulate the immune system. When stress levels go up, it changes the level of cytokines.
This kind of roundabout causal chain explains some of the many different influences pessimism, cynicism and defeatism have on the immune system. For example, when people are given a vaccination for Hepatitis B or the flu, their immune system responds. Researchers have found that stress suppresses T-cell activity and measurably lowers antibody levels.
It's a common observation of doctors that people don't recover from surgery as well if they are very anxious and depressed before the surgery, but researchers have only recently begun to find out how this could be possible. Like the study above, another experiment deliberately injured volunteers and then carefully measured the immune response to see if the more stressed volunteers' immune response differed from the less stressed ones. It did.
The researchers created minor blisters on the volunteers' forearms and then removed the top skin layer of the blisters, sterilized it and covered it with plastic. They then tested the fluid in the blisters five hours later and then 24 hours later.
They were looking for two specific cytokines and the number of cells called neutrophils (a key cell your body uses to repair an injury).
The number of neutrophils was no different in stressed and unstressed people. But the number of cytokines was significantly lower in stressed people. They tested the volunteers' stress level by measuring the cortisol in their saliva. There was a strong correlation: The higher the cortisol level, the lower the cytokine level. Stress directly suppressed their immune response.
And thinking pessimistically, cynically, and defeatedly increases your stress level. That is one reason pessimism must be crushed! ;-)
Researchers at the University of Texas Cancer Center discovered that stress hormones like norepinephrine (also known as noradrenaline) blocked the ability of macrophages to kill tumor cells. Macrophages are one type of white blood cell that surrounds and destroys invaders.
Here again, we see a chain reaction: An event happens and you interpret it. If pessimism has a hold of your mind, the event causes stress hormones to be released into your blood stream. The stress hormones then weaken and hobble your immune system, making you more vulnerable to any number of health problems.
Feelings of confidence can influence your immune system. UCLA researchers tested the immune systems of a group of first-year law students at the beginning of a semester. By mid-term, those who thought pessimistically about their chances of succeeding had weaker immune systems by mid-term. Those who weren't under the influence of pessimism still had strong immune systems by mid-term.
If you know anything about evolution, you have probably had the thought, "Wouldn't our immune systems have evolved to kick into high gear during stress rather than slowing down?" But the body is making a trade-off. Stress hormones activate your body to deal with an immediate, physical threat. Stress hormones release blood sugar and rush it to your muscles. They speed up the heart and breathing rate, etc. When a virus enters your system, however, it doesn't upset you. No adrenaline is poured into your blood stream. You don't even know it happened until later. It is an altogether different kind of threat, and we have evolved an altogether different system to deal with it.
A stress response is an evolved response designed to be brief and infrequent. During a stress reaction, your immune system is temporarily hampered, but for a good cause: You moved quickly up a tree and evaded the pride of lions. Given the world we now live in, which is much different than the environment our bodies evolved to handle, pessimism, cynicism, and defeatism can produce more frequent stress reactions that last longer, which puts our immune systems are in danger.
As if this wasn't enough, it gets worse. Pessimism influences the way you speak, and the way you speak influences the way you argue with your spouse, and the way you argue determines how stressful those arguments will be.
Negative speech patterns obviously express negative thought patterns. And when you argue with your spouse using "negative fighting behaviors" as the researchers call them, it causes extra stress for your spouse. And the stress you cause your spouse impairs your spouse's immune system. But your negative fighting behaviors also impair your own immune responses.
Negative fighting behaviors stem from negative thinking patterns. Pessimism, cynicism, and defeatism are expressed in arguments in the form of name calling (labeling your spouse with a negative label), being sarcastic, finger-pointing, and withdrawing in hopeless exasperation (giving up, feeling helpless and defeated).
These negative fighting behaviors have been studied and they do indeed result in impaired immune functioning. They also increase the chance that the marriage will end in divorce, and divorce itself usually has an enormously negative impact on the immune system.
The average married couple has a serious argument about once a month, with small quarrels in between. Studies show if a couple never disagrees, if they avoid conflict, they will have less intimacy and problems are more likely to go unsolved. That's pretty obvious.
But if they disagree badly — if they think pessimistically, if they are cynical, if they get defeated easily by setbacks — they are more likely to divorce, and, more to the point for this section, it will be bad for their immune systems.
Howard Markman of the University of Denver, an expert on marital discord, has tried to figure out what the financial costs of marital fighting is. He estimates that Americans lose almost three billion dollars a year in diminished productivity. That's not even counting the damage to doors and frying pans.
Conflicts between husbands and wives lead to more illnesses and sick days. And even when they go to work, an argument with a spouse is likely to impair their performance at least a little.
Ohio State University researchers coaxed married couples to spend a half hour arguing about whatever topic got them the most angry at each other. The researchers looked at their fighting behaviors and measured their immune systems.
The researchers labeled behaviors like accepting responsibility, finding points of agreement, and suggesting compromises as "positive fighting behaviors." They labeled behaviors like criticism, blaming, sarcasm, disapproval, dismissal, and withdrawal as "negative fighting behaviors."
The couples' immune functions were tested before and after the half-hour argument. Everyone's immune function was weakened at least slightly from the argument. But the immune function was significantly weaker in those who used the most negative fighting behaviors.
So this is another angle on the same point: Pessimism is bad for your immune system. The researchers also found that the negative fighters had more antibodies for the Epstein-Barr virus, a virus that most of us keep in check fairly easily. The presence of more antibodies means that their immune systems were not just impaired from the immediate stress, but that their immune systems were not as effective in general. The way they fight is only an easily-seen display of the way they think, and the way they think is constantly disabling their immune system.
This information only scratches the surface. The studies go on and on. New ones are continually coming out. You can use this summary, however, to give you ammunition when you influence your loved ones to destroy the pessimism in their own minds. This information gives us a strong motivation to do something about it. It is not merely "nice" to feel more positive — it is imperative if we want to live a healthy life.
And hopefully it motivates you to root out and destroy the last remnants of pessimistic thinking lurking in your own mind. And to protect yourself from further infection from the pessimism that is constantly trying to worm its way into your mind. Here is where to start: Undemoralize Yourself.
Pessimism doesn't just weaken your immune system. It is also hard on your heart. Read more about that here: Pessimism and Heart Disease.
Adam Khan is the author of Antivirus For Your Mind: How to Strengthen Your Persistence and Determination and Feel Good More Often and co-author with Klassy Evans of How to Change the Way You Look at Things (in Plain English). Follow his podcast, The Adam Bomb.