By Nicholas Perricone, MDReprinted with permission from Dr. Perricone's 7 Secrets to Beauty, Health, and Longevity: The Miracle of Cellular Rejuvenation (Ballantine Books, 2006).
As the mind-body connection has become accepted in mainstream medicine, an entirely new branch of medicine has emerged, known as psychoneuroimmunology. In true holistic fashion, this exciting new area of research brings together knowledge from multiple fields of study in endocrinology, immunology, psychology, neurology, and other fields.
Psychoneuroimmunology integrates the systems of the body and allows us to recognize that cellular rejuvenation can take part on all levels of the mind and body. Perhaps most important, we can learn to control negative emotions and thought processes that upset the delicate balance of health and well-being.Setting Stress in Motion
To understand how the mind directly impacts the body, we need to have a little background. Organs that produce hormones are called endocrine glands. (While the brain and kidneys also produce hormones, they are not considered endocrine organs, since this is a minor part of their function.) In Greek, hormone means "to set in motion"; hormones are made by endocrine glands to control or set in motion another part of the body.
The endocrine system works hand in hand with the nervous system. In fact, the endocrine and nervous systems are so closely linked that they are more accurately viewed as a single neuroendocrine system, which performs several critical tasks:
- Maintains the body's internal steady state or homeostasis (nutrition, metabolism, excretion, water and salt balances)
- Reacts to stimuli from outside the body
- Regulates growth, development, and reproduction
- Produces, uses, and stores energy.
The neuroendocrine system is designed to help ensure each individual's safety from external or internal threats, and the hormones most responsible for this task are called "stress hormones."The Stress Hormones
I have written extensively about the hormones insulin and cortisol, also known as the death hormones. Both of these hormones are necessary for good health, but when their levels are elevated, they cause serious damage, including diseases such as diabetes and obesity. Stress hormones are important—they can give us the extra burst of energy needed to get out of the way of an oncoming automobile or other impending deadly threat. However, in today's world, they are called into play too often, placing the neuroendocrine system under particular strain. The physical ramifications of negative emotions are alarming and far reaching. And while caregivers appear to be at particular risk, none of us is immune to stress and its effects. Cell phones, email, and other technological gadgets ensure that we almost never have a minute's peace to unwind and lower our stress levels.
At elevated levels, insulin and cortisol are inflammatory agents. Many of us suffer an excess of both of these hormones, the first from too many sugars and other carbohydrates in our diets, the second from too much stress and caffeine. Fortunately, we can modify our behavior to eliminate their negative effects. Giving up sugars and starchy foods will help keep our insulin levels normal. Eliminating coffee will help control our cortisol. A study conducted at Duke University found that the effects of morning coffee consumption can exaggerate the body's stress responses and increase stress hormone levels all day long and into the evening. This is a high price to pay for that morning jolt to our systems.
Stress can affect us even at the very beginning of our lives. According to the Wall Street Journal, recent studies show that women who experience high levels of stress or anxiety during pregnancy increase their risk for delivering prematurely or delivering infants with low birth weights or other health problems, including respiratory and developmental complications. In addition, maternal stress during pregnancy is believed to affect the formation of the important hypothalamic-pituitary-adrenal (HPA) axis. A major part of the neuroendocrine system, the HPA axis controls reactions to stress and plays an important role in the regulation of body processes, including digestion, immunity, and energy use.
There is also increasing evidence that suggests that the detrimental effects of glucocorticoid (GC) hypersecretion (overproduction of steroids), which occurs when the HPA axis is activated, results in a number of diseases, including obesity, Alzheimer's, AIDS, dementia, and depression. Fortunately, there are some targeted nutritional supplements, described later in this article, that can help keep the all-important HPA axis in balance.How Cells Get Old Before Their Time
We all know that dealing with heavy stress can make us feel older than we really are. But a recent study at the University of California at San Francisco suggests that it isn't just a feeling—stress actually accelerates the rate at which cells age. It's an established fact that stress precipitates premature aging, but until recently, the exact mechanism of how this occurs has been unclear.
According to this study, stress affects telomeres, strips of DNA at the end of chromosomes, which appear to protect and stabilize the chromosome ends. (A chromosome is a threadlike structure of DNA and associated proteins that is found in the nucleus of a cell.) Chromosomes carry genetic information in the form of genes. These key pieces of DNA are also involved in regulating cell division. Each time the cell divides, the telomere shortens, until eventually there is nothing left, making cell division less reliable and increasing the risk of age-related disorders.
Scientists took blood samples of 58 premenopausal women to carry out DNA analysis of telomeres. They also measured levels of an enzyme called telomerase, which helps build and maintain telomeres in immune cells.
Nineteen of the women in the study had healthy children and the rest had children with chronic illnesses. Being a caregiver is a highly stressful situation, and it was not surprising when the researchers discovered that women who had reported higher levels of psychological stress—those who were caring for sick children—had shorter telomeres. In fact, the difference was equivalent to more than a decade of additional aging when compared with the women who had lower stress levels.
The high-stress group also had lower levels of telomerase in their immune cells. According to Elissa Epel, PhD, leader of the research team, this finding implied that the immune cells would not function as well and could die sooner. It was also found that the high-stress women had greater levels of oxidative stress—cumulative damage caused by free radicals. Laboratory studies have confirmed that oxidative stress speeds up the shortening of the telomeres.
The researchers further stated that it was not clear exactly how stress affected telomeres, but they suggest that changes in stress hormone levels could have an effect.Stress Has Teeth
It isn't just mothers of children with chronic illness who experience high levels of stress-related health problems. A fascinating study published in the journal Psychosomatic Medicine found that caregiver spouses of patients with Alzheimer's disease develop gingivitis, an inflammatory gum disease, at twice the rate of their noncaregiver counterparts. Since there was little difference in oral hygiene between the two groups in the study, the researchers believe the difference might have been related to stress. (The authors of the study also note that the relationship between chronic stress and severe gum disease was first noticed in soldiers in the trenches during World War I, hence the rather graphic term trench mouth.) Gum disease is serious enough in and of itself. It can lead to serious bone destruction and tooth loss. But as we will find out, it may also precipitate serious life-threatening diseases.
Lead investigator Peter Vitaliano, PhD, of the University of Washington School of Medicine in Seattle, stated: "On a practical level, [the study's results] speak to relationships between chronic stress and oral health in the general population and suggest that these are independent of oral care. They show that caregivers are at risk for oral health problems and not just physical health problems."
The investigators not only evaluated the subjects' gum disease but also measured the key components of metabolic syndrome:
- blood insulin levels
- intra-abdominal fat.
The caregiver spouses scored higher on all three of these measures, placing them at great risk for type II diabetes.More Reasons to Floss Your Teeth
In addition to the deleterious effects of stress on health including oral health, the American Academy of Periodontology has also linked periodontal (gum) disease to heart disease. One theory they put forth is that oral bacteria produced by the gum disease can affect the heart when the bacteria enter the bloodstream, attaching to fatty plaques in the coronary arteries (heart blood vessels) and contributing to clot formation.
Coronary artery disease is characterized by a thickening of the walls of the coronary arteries due to the buildup of fatty proteins. Blood clots can obstruct normal blood flow, restricting the amount of nutrients and oxygen required for the heart to function properly. This may lead to heart attacks.
Another possible reason they put forth is that the inflammation caused by periodontal disease increases plaque buildup, which may contribute to swelling of the arteries. Researchers have found that people with periodontal disease are almost twice as likely to suffer from coronary artery disease as those without periodontal disease. Periodontal disease can also worsen existing heart conditions. This may well be another important link between stress and heart disease—a cause and effect: stress exacerbates gum disease, which can then lead to heart disease.
Additional studies have also linked gum disease and stroke. Researchers have found that the risk for stroke is 2.8 times greater for individuals with periodontal disease than those without periodontal disease. It is clear that there is a significant inflammatory component linking all of these syndromes and diseases, which is immensely important when we realize that inflammation directly impacts the progression of gum disease, heart disease, and atherosclerosis.Our Immune System: The Key to Cellular Rejuvenation of the Brain
New research shows that immune cells contribute to maintaining the brain's ability to preserve cognitive ability and cell renewal throughout life. It has been generally accepted, until recently, that each individual is born with a fixed number of nerve cells in the brain. As these cells gradually degenerate and die during the person's lifetime, they cannot be replaced. This is especially alarming when we realize that chronically high levels of stress-induced cortisol, so common in the world of today, cause the brain to shrink.
However, this theory was disproved when researchers discovered that certain areas of the adult brain do retain their ability to support and promote cell renewal (neurogenesis) throughout life, especially under conditions of mental stimuli and physical activity. The hippocampus, which supports certain memory functions, is one such area. A team of scientists, led by Professor Michal Schwartz of the Neurobiology Department of the Weizmann Institute of Science in Rehovot, Israel, one of the world's top-ranking multidisciplinary research institutions, has come up with new findings that may have implications in delaying and slowing down cognitive deterioration in old age. These findings showed that the primary role of the immune system's T-cells (white blood cells responsible for the body's immunity) is to enable areas of the brain such as the hippocampus to form new nerve cells and maintain cognitive function. We still don't know how the body delivers the message instructing the brain to step up its formation of new cells. However, animal studies have shown that exposure to an environment rich with mental stimulations and opportunities for physical activity led to increased formation of new nerve cells in the hippocampus. (As with muscle, it appears that the phrase "use it or lose it" also applies to brain power.) When the scientists experimented with mice that lacked T-cells and other important immune cells, significantly fewer new cells were formed.
According to Professor Schwartz, "These findings give a new meaning to ‘a healthy mind in a healthy body.' They show that we rely on our immune system to maintain brain functionality, and so they open up exciting new prospects for the treatment of cognitive loss."
Knowing that the immune system contributes to the renewal of nerve cells has potentially great significance for aging populations because aging itself is associated with a decrease in immune system function. Aging is also associated with a decrease in memory skills and the formation of new brain cells. Therefore, by manipulating and boosting the immune system, it might be possible to prevent or at least slow down age-related loss of memory and learning abilities.Stress and Cholesterol
Previous studies have established that stress is linked to increased heart rate and weakened immune systems. Now researchers have discovered that elevated stress levels appear to raise cholesterol levels over the long term. This is alarming because elevated cholesterol is a risk factor for heart and circulatory disease, the number-one killer of both men and women in the United States.
A team of researchers, led by Professor Andrew Steptoe from University College London, put forth three hypotheses on how stress increases cholesterol levels:
- Stress may encourage the body to produce more energy in the form of fatty acids and glucose, requiring the liver to produce and secrete more low-density lipoprotein (LDL) so that they can be transported to the other tissues of the body.
- Stress interferes with the body's ability to rid itself of excess cholesterol.
- Stress triggers a number of inflammatory processes that also increase cholesterol production.
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