A large part of our survival instinct involves what is known as our fight or flight response, which as the name implies, urges the body to either confront a fearful situation or more practically, get away from it.

In order to better accomplish this goal, certain bodily functions must step up their production, including our heart rate, breathing, and muscles, and these modifications in our metabolism are generally initiated by signals from the brain, mainly in the form of hormones.

One such hormone is cortisol, often referred to as a stress hormone, which is integrally involved in our body's fight or flight response. The problem is, while cortisol may have helped our ancestors to get away from predators and return safely to their caves, there is less of a need for this in the modern world.

That is not to say, however, that our bodies no longer respond to stress. If anything, the hectic and demanding pace of our world is a constant source of stress, and our bodies respond accordingly.

Unfortunately, the constant subjugation of our bodies to stress hormones can have negative health consequences, some of them significant. In fact, a new study published in the Journal of Clinical Endocrinology and Metabolism has suggested that high levels of cortisol can increase the chance of dying from heart disease.

In the study in question, researchers followed 860 individuals over the course of six years. All subjects were over the age of 65 years and cortisol levels were measured by way of urinalysis. What they found was that the individuals with the highest levels of cortisol increased their risk for death from heart disease by five times. No links were determined between high cortisol and other causes of death.

Previous research has also found links between cortisol levels and obesity, high blood pressure, and atherosclerosis, all of which comprise what is known as metabolic syndrome, a risk factor for heart disease. While earlier work as well as anecdotal evidence all indicate that stress can exacerbate heart disease, the current study is the first to directly test this theory and thereby present evidence that cortisol can in act damage the health of our hearts.

However, experts also acknowledge that our stress response is a complicated process, and many chemicals and hormones are in play. With this in mind, cortisol may play a significant role, but more work needs to be done to better understand the complex interactions that are going on.

In the meantime, the take home message from all of the data is that too much stress is bad for you, and you should try to reduce it in your life. For more information and some helpful tips, visit the website for WedMD.