Researchers have finally proven that feeling "stressed out" isn't just something in our heads, it also shows up in our bodies - and it can have deadly consequences.
In a paper published in the January 15 issue of the New England Journal of Medicine, Bruce S. McEwen, PhD, of Rockefeller University, identifies eight physical indicators in the body - from blood pressure to cortisol levels to abdominal fat- that can be measured to give a tangible indication of an individual's personal stress load.
McEwen introduces the concept of what he and his colleagues have labeled "allostatic load," which is the price our bodies pay for the ability to adapt to stress. "From the standpoint of health," says McEwen, "what is even more important than how we feel about the stressful events in our lives is how our bodies react in terms of the stress hormones they produce."
Stressful life events - whether the loss of a loved one, divorce or job loss - as well as the daily wear and tear of living, such as traffic jams and family disagreements, set off the release of stress hormones that help our bodies charge up to meet the challenge.
"During episodes of acute stress, stress hormones provide a protective function by activating the body's defenses," says McEwen, "but when these same protective hormones are produced repeatedly, or in excess, because of chronic stress, they create a gradual and steady cascade of harmful physiological changes."
Higher levels of allostatic load can lead to suppression of the immune system (which leaves us open to infection and infectious diseases), as well as bone loss, muscular weakening, atherosclerosis and increased insulin levels that cause higher levels of fat deposition in the body, especially around the abdomen.
"People end up with that 'apple' body shape that researchers have shown over and over again predisposes us to heart disease," says McEwen.