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Stress: The Killer Disease

Stress and inflammation leave us vulnerable to depression.

Stress Kills. We’ve heard it before. It’s common sense. But how does stress kill? As a physician, I tend to imagine stress leading to high blood pressure and heart attacks and anxiety or depression. But how could stress, alone, do all that? Sure, there are stress hormones that get out of whack and cause chronic activation and damage in our brains and vasculature, but how do they do that? How does stress kill?

Lifetime exposure to chronic psychological stress is associated with elevated inflammation in the Heart and Soul Study.

I like the Heart and Soul Study. They are on my wavelength. The methods are solid. All the subjects have a history of some sort of cardiovascular disease, which is important (and they are mostly male, derived mostly from patients at the Veteran’s Association, so keep that in mind). And here they have looked into people's history of psychologic stress, measured their inflammatory cytokines, and hypothesize a connection. Inflammatory cytokines are chemicals released by the immune system activating armies of cells to attack invaders such as viruses, pathogenic bacteria, or cancer. The problem is that our immune system can be over-activated and lead to autoimmune disease. Most modern chronic disease, including atherosclerosis and depressive disorders are associated with elevations in these cytokines, elevations in autoimmunity, and diseases that linger and are difficult to eradicate and treat. The connection is confirmed by many other studies linking a history of trauma (all sorts) to elevations in cytokines.

The down-low is that stress is linked to bad cytokines (IL-6, TNF alpha, C reactive protein, etc.) and that stress is linked to PTSD and Major Depressive Disorder and anxiety disorders which are also linked to the bad cytokines… as is cardiovascular disease, even in psychologically healthy individuals. In addition, there are harmful behaviors which increase the inflammatory cytokines (substance abuse, smoking), and ameliorating behaviors that decrease them (exercise, meditation, sleep) less likely to be adhered to by those who have undergone inordinate psychological stress.

Where the rubber meets the road is that higher lifetime trauma was associated with higher levels of inflammatory cytokines at baseline and 5 years later. When the researchers controlled for psychological symptoms of the trauma (for example, PTSD or a clinical depression), the relationship held, meaning those who had undergone trauma had elevations of inflammation even if their behavior and coping seemed more normal by psychiatric diagnostic standards. In these folks with pre-existing cardiovascular disease, higher inflammation is associated with greater risk of death and complication.

Can you avoid trauma? Not always. But through a healthy lifestyle, good wholesome nutrition, and stress reduction, you can sometimes ameliorate the long term damage. Researchers are beginning to measure the effects of these interventions in the body, using cytokine levels. The secret of how stress kills will not be a secret for too much longer.

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Copyright Emily Deans, MD