by Barbara Cook
For centuries, much attention has been given to the influence of the mental and emotional processes on health and disease. Today, we believe with certainty that the mind (the consciousness) can affect our physical health.
Emotions are what unite the mind and body. In a study, published online in Psychological Science, researchers suggest that positive emotions bring us better health — and good health generates more positive emotions. “Recurrent momentary experiences of positive emotions appear to serve as nutrients for the human body,” they write, “increasing feelings of social belonging and giving a needed boost to parasympathetic health, which in turn opens people up to more rewarding positive emotional and social experiences.”
Aristotle was among the first philosophers to suggest a connection between mood and health — a link between the soul and the body. For Aristotle, the soul is to the body as form is to matter; they are inseparable. “Soul and body, I suggest, react sympathetically upon each other,” he is credited with saying. Hippocrates, the father of Western medicine taught that good health depends on a balance of mind, body, and environment.
Many ancient healing systems emphasize the interconnection between mind and body in healing. Ayurveda and Traditional Chinese Medicine have a long history of focusing on the mind–body–spirit connections and the effects of emotional/energetic imbalances on health.
Since the early twentieth century, numerous scientific studies and experiments were conducted to show the correlation between physical health and the conditioning of the brain.
In the 1920’s and 30’s pioneering Russian scientists conducted studies showing that the classical Pavlovian conditioning* could both suppress and enhance the immune system. They performed repeated trials with small animals trained to activate their immune systems without stimulus. First they gave the guinea pigs and rabbits an injection that stimulated the immune system every time they honked a horn. Eventually the animals became so conditioned, that they could activate their own immune system without the injection as the horn was honked.
American scientists continued the research on the communication links between the brain and the immune system. Psychologist Robert Ader of the University of Rochester School of Medicine and his colleague Nicholas Cohen did a series of groundbreaking experiments in the 1970’s. They trained rats to associate certain stimulus with an event. In the studies rats were given an immune-suppressing drug flavored with sweet tasting saccharin. Eventually the rats became so conditioned to this drug that the saccharin taste alone, seperated from the drug, caused a suppression of the immune system – demonstrating that mental cues can alter physiology.
While the study showed that the immune system could be conditioned at the autonomic level, or subconscious level, Howard Hall in 1990 demonstrated that the immune system could be consciously controlled. In his research, he instructed his human subjects to use several self-regulatory techniques (self-hypnosis, guided imagery, relaxation training) to consciously increase the stickiness of their white blood cells, which then was measured by saliva and blood tests. Hall was the first to show that psychological factors (conscious intervention) could directly affect cellular function in the immune system.
In the 1940’s Wilhelm Reich proposed the unorthodox idea that cancer is the result of failure to express emotions, especially sexual emotions. Reich was not only ridiculed by the medical and scientific establishment, he was actually persecuted. The United States government held an official book burning, calling for all available copies of Reich’s work to be rounded up by the FDA and incinerated.
In the 80’s Lydia Temoshok, a psychologist at UCSF showed that cancer patients who kept their emotions such as anger under the surface, remaining ignorant of their existence had slower recovery rates than those who expressed emotions. Temoshok found that another trait common to cancer patients was self-denial, stemming from an unawareness of their own basic emotional needs. Her study showed that the immune system was stronger and the cancerous tumors smaller for those in touch with their emotions.
Can suppressed anger and other negative emotions cause cancer?
It is a fact that every one of us has a number of tiny cancerous tumors in our bodies growing every moment. Candace Pert PH.D., author of Molecules of Emotion explains that the part of the immune system that is responsible for the destruction of the errant cells consists of natural killer cells whose job it is to attack these tumors, destroy them, and rid the body of any cancerous growth. In most of us most of the time, these natural killer cells do a good job, a job coordinated by various brain and body peptides and their receptors, therefore these tiny tumors never grow large enough to cause us to be ill. 
Is it possible that we could learn to consciously intervene to make sure our natural killer cells keep doing their jobs? Is emotional health essential to physical health?
All honest emotions are healthy emotions. Anger, fear, and sadness can be as healthy as peacefulness, courage, and joy – as long as they are expressed. According to Pert, repressing these negative emotions and not letting them flow freely “is a set up to dis-integrity in the system, causing it to act at cross-purposes rather than as a unified whole.” The stress caused by holding in negative emotions takes on the form of blockages and insufficient flow of peptide signals that maintain function at the cellular level. 
Health is not just a matter of thinking happy thoughts. Pert suggests that sometimes the biggest impetus to healing could come from jumpstarting the immune system with a bust of long suppressed anger. How you do it is up to you. Scream into the pillow or in a room by yourself. Let it out in group therapy. Or have a heartfelt, spontaneous exchange with a family member or friend for venting and expressing how you feel. The key is to express it, so it can stop poisoning you and your cells.
*Pavlov trained his dog to associate the sound of a bell ringing with the approach of food.
 How Positive Emotions Build Physical Health, Psychological Science, May 6, 2013
 Molecules of Emotion by Candace Pert PH.D.