It is a well-known phenomenon. A grieving wife or husband has a cardiac event and dies suddenly soon after the death of a spouse. We attribute this to stress as we do other physical breakdowns that occur at times of high pressure. Deaths are more common around major holidays or on the anniversary of a tragic event. How does that happen? Is it real? The facts are incontrovertible. We say, “He/she died of a broken heart,” and attribute it to stress.
There is increasing evidence that how we live our life is directly related to our health and longevity. Eating well, getting enough sleep, exercising regularly and managing stress are being shown in study after study to have important effects. The effects and mechanisms of stress have been more clearly elucidated in a recent article in the journal Lancet and summarized in the April issue of the Harvard Heart Letter. The study looks at the means by which stress brings about physical changes to our bodies.
The amygdala is an almond-sized area in the center of the brain that mediates our responses to perceived threats. The amygdala stores our emotionally charged experiences from the past and reacts instantaneously to events or situations that resemble them. It is this location in the brain that triggers an immediate response to perceived threats, including the “fright or flight” reaction. The amygdala can’t distinguish whether the threat is real of not, just that it looks like something it remembers to be threatening. When that happens, the amygdala lights up on brain scans indicating that it is actively processing the information and sending signals to other parts of the body.
Two areas that receive these signals are the hypothalamus and the pituitary gland. The hypothalamus signals one area of the adrenal glands to immediately secrete adrenalin, and the pituitary signals another area of the adrenal to secrete cortisone. The adrenaline acts immediately, speeding up one’s heart, redirecting blood flow to the muscles and brain, and it triggers heightened awareness, dry mouth, increased sweating and it raises the blood sugar, all events that we associate with the “fight or flight” reaction. The body gears up for battle or to escape the threat. If the threat becomes longstanding, as with chronic stress, the secretion of cortisone increases over time, which has a number of deleterious side effects, like high blood pressure, stomach ulcers and malfunction of the immune system.
It has been shown in animals that chronic stress activates a third area of the body, the bone marrow. Stress activates the bone marrow to make and release white cells, infection-fighting cells. White cells are associated with inflammation, and inflammation encourages the buildup of fatty deposits in the walls of arteries, including the coronary arteries. So chronic stress in animals triggers a process that heightens the risk of coronary blockage and heart attacks.
It has not been known whether this same mechanism occurs in humans until the recent Harvard-Lancet study. The study, through the use of PET/CT scans of the brain, looked at the activity of the amygdala, the bone marrow and the presence of inflammation in the arteries and found that heightened activity in the amygdala was associated increased activity of the bone marrow, inflammation in the arteries and a higher risk of heart attack or other cardiac events. These findings confirm that stress has real physical consequences and helps to explain the mechanism. The amygdala helps people to sense and evaluate external stress and to mount an internal physiologic response. However, this response can be dysfunctional in people who are subject to sudden severe or prolonged stress or people who have higher levels of amygdala activity. How we manage our lives and what we feel and think has real consequences to our health.
What to do? Well, there is no glib easy answer. Ideally, if it is possible to reduce the stress by modifying your circumstances, that is the best answer, but very often this is not possible, at least not in the short run. Other methods of reducing stress are exercise, yoga and meditation. Walking, running, biking and swimming are all potentially good stress reducers. It depends on the person and what relaxes him or her. For some people, just getting out of doors for a period of time is enough to reduce the stress. It is highly recommended that you break up a long day with one or two short bits of activity. Even 15 minutes of walking or quiet meditation can lower body’s stress reaction.
Meditation has become a much more acceptable form of stress reduction. It was originally associated with certain religious practices, particularly Buddhism. However, in the 1980s, Herbert Benson at Harvard Medical School discovered that by sitting quietly and narrowing your mental focus to a single thing (a sound [Om}, a word [peace}, or your breath) for 20-30 minutes each day that your physiology changes. Blood pressure lowers, muscles relax, and brain waves change from an alert pattern to a more relaxed state. It takes some practice to do this, and the alert mind tends to want to focus on the problems and thoughts of the day, but it can be learned with practice, and it has carryover effects to the whole day. There many classes that teach meditation, or as Benson called it, “the relaxation response”. The practice can also be called upon when facing a highly stressful circumstance. For example, I’ve had several MRIs in my life, and I have learned that when I feel claustrophobic to narrow my focus to my breath so that I can detach from the circumstances.
So in summary, stress has real effects on our physiology, potentially destructive effects if it goes on chronically. These effects are mediated through the brain, which activates hormones (adrenalin, cortisone) and inflammatory cells, which in turn negatively affect the blood flow to our heart and other organs. Learning means of managing stress is important to our health and longevity.