The human brain is like no other in terms of its ability to simultaneously synthesize information and carry out complex tasks on a regular basis. While it would be naive to say that we fully understand its interrelationship with the rest of the body and our environment, modern research has made great strides to elucidate its various structures and functions. Here is a brief look at our current understanding of cognitive function and the risk factors that threaten its well-being. While a focus on memory is highlighted, all aspects of cognitive performance including language, reaction time, focus, mood and information
Arguably, we are more stressed today than ever before in human history. As a result, stress accounts for 75 – 90% of all primary care visits in the US, and prescriptions for antidepressant and anti-anxiety medications are sky-rocketing. Many people recourse to self-medicating with substances such as stimulants, drugs, alcohol, tobacco and even food in an attempt to manage their mental stress. Stress is also considered to be the number one reason why people eat poorly and
Reducing the Effects of Stress
The use of botanical preparations aimed at helping the body to balance is a traditional practice worldwide. The efficacy of adaptogens such as ginseng, licorice, Ashwagandha, holy basil, Bacopa, etc. is now validated by scientific studies. Formulas combining botanical and adrenal gland extracts are superior since their various mechanisms of action complement each other to modulate the multiple pathways affected by stress. Trying to reduce levels of stress in one’s life and getting proper rest and nutrition are critical in order for the body to remain biochemically balanced and equipped to cope with life’s challenges.
The Mind-Body Connection
In contrast to Chinese and other traditional medicine philosophies, Western medicine has long claimed that the mind and body are separate entities. In light of recent scientific research however, an increasing number of researchers and physicians now recognize that what happens in the mind can profoundly influence the body.
The Stress–Illness Connection
Stress is so widespread that the word tends to lose its meaning. In neuroscientists’ terms, stress is defined as: “Conditions where an environmental demand exceeds the natural regulatory capacity of an organism, in particular situations that include unpredictability and uncontrollability.” The stress response is meant to improve your chances of surviving a physical threat to your safety temporarily, but prolonged, frequent or extreme stress can have devastating effects on the body and brain. It is fair to say that nearly all illness is stress-related: it either causes stress, is caused by stress or is aggravated by stress. While the mechanisms by which stress contributes to the disease process is yet to be fully understood, research shows that chronic stress causes significant dysfunction of the neuroendocrine system.
There are many health challenges associated with chronic stress such
Stress 101 – General Adaptation Syndrome
Back in the 1930s, Hans Selye observed that both psychological and biological stress can impact our health through interactions between the mind and the adrenal glands. Selye observed that when faced with stressors (either physical or psychological), all living organisms react in physiologically predictable patterns in order to maintain their metabolic equilibrium, or homeostasis. He described this response in a three-step process which he has coined the “General Adaptation Syndrome” (GAS), see figure 2.
Stage 1 – Alarm phase: Upon encountering a stressor, the nervous system sends an immediate alarm signal to the brain, resulting in the activation of both the “fight-or-flight” response and the hypothalamic-pituitary-adrenal (HPA) axis. The “stress” hormones including corticosteroids (i.e. cortisol) and catecholamines (i.e. adrenalin) are released into the bloodstream. The body’s resources are then mobilized to deal with the perceived threat or danger.
Stage 2 – Resistance: If the
Stage 3 – Exhaustion: If the
How Stress Affects the Neuroendocrine System: The HPA Axis
The intricate connection between our brain and the system of glands that
Cortisol is involved in multiple bodily functions and its primary roles include: 1) Increasing blood sugar synthesis in the liver, 2) Assisting in fat, protein and carbohydrate metabolism, and 3) Supressing the immune system to allow the body to perform priority or life dependant upon tasks. It also decreases bone formation. Cortisol is needed to maintain optimal health, but too much or too little can be deadly. Hormones are maintained at the optimal level via a tightly regulated system of feedback loops. During stressful periods however, cortisol is secreted at an increased rate to support the breaking down and the use of fatty acids and proteins needed for energy production. Building on Selye’s original work, researchers have demonstrated that both acute and chronic levels of stress contribute to high levels of cortisol.
Biochemical Effects of Stress
• Steroid Hormone Imbalance
Stress-induced over- activation of the HPA axis and its resulting adrenal dysfunction profoundly affects hormonal balance in several ways. The adrenals are responsible for approximately 35% of steroid hormone production prior to menopause and for at least half of their production after menopause onset. All steroid hormones are disrupted by stress, but progesterone is particularly vulnerable to the devastating effects of chronic stress because it is used as raw material for the production of cortisol. For examples of different types of steroid hormones see Figure 1.
• Thyroid Dysfunction
In conventional medicine, thyroid disease is treated as a random malfunction of the thyroid gland.
Emerging studies are now supporting the claims of the many people accusing stress of being a direct culprit of their weight gain. Indeed, investigators are finding correlations between stress-induced cortisol secretion and central obesity, marked by a high waist-to-hip ratio accompanied with abdominal adiposity. Raised cortisol levels may also contribute to binge eating.
• Accelerated Aging
Telomeres are protective DNA strands found at the extremities of our chromosomes. They can be compared to the plastic caps on the ends of shoelaces. Every time our chromosomes divide, the telomeres shorten, until they become so depleted that the cell can no longer divide.
(This is known as the Hayflick limit) and eventually dies. Shortening of telomeres is an indicator of accelerated aging. Stress has been shown to accelerate the shortening of telomeres. So stress does make us age faster!
• Cardiovascular Diseases
Numerous studies have linked stress and heart disease-related problems. One of the most impressive is a 21-year prospective study reported in the European Heart Journal, involving nearly 14,000 men and women. The conclusion of the research is that chronic stress is an independent risk factor for cardiovascular disease and particularly for fatal stroke.
Provocative evidence linking cancer, stress, and elevated cortisol levels was introduced by scientists in the mid-1990s. In a case-controlled study published in 1996, researchers evaluated hormone levels of the hypothalamic-pituitary-adrenal system in women with both early-stage and metastatic breast cancer and concluded that breast cancer is associated with hyperactive adrenal glands. In another study published in Lancet Oncology (2004), researchers looking into the interactions between the HPA axis, stress, and cancer reported that: “stress and depression result in an impairment of the immune system and might promote the initiation and progression of some types of cancer”.
Although the root cause of this devastating illness is still being investigated, new evidence suggests that increased levels of stress, and the resulting high levels of cortisol, may be part of the equation. According to research, high cortisol levels may promote degeneration and death of neurons accompanied with decreased memory function in otherwise healthy elders from both genders. Higher cortisol levels have also been detected in Alzheimer’s disease patients and are linked to cognitive and memory impairments.
Ordinarily, after a perceived stressor has passed, our system adjusts by raising and lowering different biochemical levels and returning the body to its state of homeostasis. In today’s world however, our regulatory capacity becomes overwhelmed by the extent, duration, intensity, frequency, or multiple layering of stressful events that can result in a prolonged state of homeostatic imbalance.
It is important to
What You Need to Know
It has long been known that stress has a profound effect on our physical and mental well-being and is linked to illness and disease. Stress can upset the delicate balance of chemicals and hormones in our neuroendocrine system and specifically in the hypothalmic-adrenal-pituitary axis. Research has demonstrated that many health conditions are caused by and/or accelerated by chronic stress. The different phases of the body’s reaction to stress are described in what is known as General Adaptation Syndrome, coined in the 1930’s. Understanding how our bodies react to external and internal stressors and finding natural strategies to cope with them is vitally important in our quest for optimal health and well-being. Adopting lifestyle changes to reduce stress and supporting the body nutritionally are the first steps in coping with the stress demands that are a part of life.