By Dr. Bob Kroeger
An article in the March 21 ADA News detailed the plight of a dentist who claimed he carried stress in his neck, which eventually culminated in a spinal cord infection that left him paralyzed. After returning to his practice, he asserted that dentists’ stress levels are so high that they compromise immunity. I can’t validate that his distress caused his infection, but reading the article made me glad I’m writing this column.
A definition of stress is a non-specific response of the mind and body to any change in our environment. The change is called a stressor (for example a broken appointment). Our response can be one of distress (lots of angry feelings and a few nasty but well deserved words), one of eustress (how can we fill that hole?), or one of relaxation (the relaxation response). In the first two reactions, the stress response starts in our bodies. Here come the chemicals!
Let’s examine this stress response, best explained by the Canadian researcher Dr. Hans Selye in 1936. His hypothesis, called the General Adaptation Syndrome, involves an alarm state (the stressor appears), a resistance state (the body and mind react), and the exhaustion state (bodily defenses break down). He also was the first to explain the HPA axis (hypothalamus-pituitary-adrenal), which triggers the release of the “stress” hormones. So when we are faced with a stressor, our brain sends a chemical signal to our pituitary gland, which in turn sends a signal to our adrenal gland and other places in the body. The most significant stress hormones released into the bloodstream are cortisol, epinephrine, and norepinephrine. These come in handy if we are being attacked by a bear, mugger, or angry dental assistant. Our heart needs to supply us with the needed energy to escape the danger. But, if this chemical attack continues over a long period of time, our body suffers.
Heart disease, the No. 1 killer of dentists (outside of irate staff), deserves discussion. If epinephrine hangs around long enough, it mobilizes fat from fat cells (a big belly) and moves this fat into the blood stream, where it forms deposits in arteries and narrows arterial walls (feel your blood pressure rising?). If loosened, these deposits can become stuck in heart or brain vessels, causing heart attack or stroke.
Cortisol is another villain. Its effects are explained through a new science called pyschoneuroimmunology (PNI). Over the last 10 years, studies have documented that our natural killer (NK) cells (these fight against bacterial and viral infections and subdue cancer cells) fall with the rise of cortisol. Cortisol and its buddies aggravate over 80 autoimmune diseases.
Another factor is duration of the stressor: the longer the exposure, the higher the risk of disease. Rarely does one get a disease during the time of stress, the disease happens later. During a marathon, cortisol and epinephrine are pumped continually into the bloodstream and remain in the body for some time afterwards. During the race the runner channels them (eustress) for maximum performance and normally suffers no ill effects. But some catch colds a few days following a marathon, presumably because their immune system was weakened (although I never have). The Glasers at Ohio State continue to produce significant research into PNI and health.
So why does Sally get sick and Kim stay healthy? There are genetics, yes, but this plays a smaller role than childhood experiences. Other factors include prior exposure to stressors (that’s the 10th parking ticket this year!), level of happiness, skills in stress management, fitness level (very important), social support, habits (alcohol, smoking, and drugs aren’t in your best interest), pre-existing disease, and nutrition.
When you’re upset at bedtime and your heart’s going thump, thump, thump as you try to fall asleep, you’re feeling stress hormones at work. If one sleepless night follows another, and another, and another, your chances of becoming sick increase. Anger can lead to sadness, which can lead to depression, one of the absolute worst problems associated with distress. It can lead to suicide, which is our topic next time. Stay tuned.
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Dr. Bob Kroeger retired after practicing general dentistry for 33 years. A stress management consultant, he presents seminars to the dental profession as well as to general industry. In addition to lecturing and writing, he runs seven to nine marathons a year and is a certified personal trainer. Contact him at [email protected].
By Dr. Bob Kroeger