Researchers worldwide have been aware of the effects of stress on human health for many years. However, recent research is revealing that chronic stress – common in modern life - doesn’t merely increase and complicate health problems; it can actually be a prime cause of illnesses.
In a recent publication on stress and health, Sheldon Cohan, a psychologist at Carnegie Mellen University reported, “we are just beginning to understand that stress influences a wide range of diseases related to aging, such as heart disease, diabetes, cognitive decline, metabolic syndromes, disabilities and even early death.
Although everyone experiences stress in their lives, it appears that individuals in their mid-life years, 40 and older, are more prone to the negative effects of stress on health. A recent Harvard University poll of mid-life respondents revealed that more than a third of the participants experienced a major stressful life event in the past year, such as a death in the family, chronic illness, major financial issues or job loss.
Chronic stress frequently leads people to eat more, drink more, smoke more, exercise less and sleep less. These are patterns of behavior that have very negative consequences for health. Stress experienced by an individual causes the release of adrenaline and cortisol into the bloodstream to enable us to react immediately to perceived threats (whether real or imaginary). This autonomic stress response system has ensured our survival amidst the real life dangers present throughout our evolution.
Chronic stress unfortunately leads to the continuous release of cortisol into the blood stream, lowering the body’s ability to fight inflammation in the body. Long term chronic inflammation damages blood vessels and brain cells, leads to insulin resistance and results in painful joint disease.
Several health conditions that are caused or significantly influenced by chronic stress are:
- Heart disease: Scientists have known for years that there is a correlation between chronic stress and heart disease. Recent research at Harvard Medical School indicated that chronic high levels of stress produce a surplus of white blood cells, which are changed by the high levels of cortisol, which turn leads to the white blood cells attaching themselves to blood vessel walls. The result is plaque build up in the blood vessels, a key marker o heart disease, leading to vascular hardening of the arteries, a major threat to healthy heart functioning.
- Ulcer and digestive problems: Although recent findings indicate that ulcers are generally caused by the bacteria H. pylori, it is known that about 15% of ulcer patients are not infected with H. pylori. One theory is that chronic stress allows the H pylori bacteria to thrive. Another is that chronic stress changes the balance of bacteria in the gut. Neuroscientist, Dr. Bruce McEwen, has stated, “The bacteria are able to grow because the immune system is not functioning properly … so ulcers ultimately come down to a stress impairment.” Scientists agree that stress can be a critical factor in irritable bowel syndrome, heartburn, ulcerative colitis, indigestion, and Crohn’s disease.
- Slower healing: Research has indicated that excessive cortisol in the blood stream slows wound healing and lowers vaccine effectiveness. Research findings also indicate that the longer the stress goes on, the longer the immune system is disrupted.
- Sleep dysfunction: Chronic stress appears to increase sleep deficit resulting in decreased amounts of deep sleep, sleep interruption (waking between 12-4am), and restlessness “wakefulness” during the sleep cycles. Research suggests that increased or prolonged stress aggravate these sleep deficits, making it difficult to achieve restorative energy from sleep. Sleep deprivation impairs memory, emotional control and our ability to handle the daily stressors in our lives.
- Back, neck and shoulder pain: Physical injuries, congenital deformities, poor posture and physical inactivity lead to frequent and common dysfunction and chronic pain in the back, neck and shoulders. Chronic stress and mental agitation does not cause the already existing physical dysfunction and pain, however, once the pain is experienced, stress can intensify both its severity and duration. Musculoskeletal pain appears to be particularly sensitive to chronic stress. Scientists theorize that stress-induced inflammation prevents the full healing that would make the pain recede.
- Depression: Although depression is often triggered by a stress-inducing life event or a constellation of stress-inducing events, depression frequently takes on a life of its own. Stressors leading to depression throw several brain neurotransmitters – such as serotonin, dopamine, and norepinephrine – out of balance. This chemical imbalance in our brain negatively affects mood state, regulation of emotions, negative thought patterns, sleep quality, appetite, anger levels and sex drive. Research with some severely depressed individuals reveal permanently elevated cortisol levels which alter brain functioning, lower the immune response, lead to increased inflammation and permanently damage brain cells.
- Weight gain: It has long been recognized that stress and its hormones stimulate a preference for foods full of starch, sugar and fat. In addition, new research reveals that individuals experience chronic stress trigger metabolic changes that result in fewer calories being burned than lower stressed individuals. The stress response produces a rise in insulin levels and fall in fat oxidation leading to a dual process that promotes fat storage. Other research has revealed a correlation between excess cortisol and abdominal fat.