Inflammation: The Key to the Link between Stress and Disease

Human beings are wired to respond to physical threat in some predetermined ways. This is our body’s way of preserving our lives. The problem is that our normal stress response is meant to be acute, not chronic. But the types of stressors modern humans encounter are often chronic, and so our stress response is out of sync with the realities of our world. When stressors are chronic, our stress response malfunctions and actually increases our risk of disease.

There are three main components of the stress response. When you understand these, you will understand the basic concepts underlying mind-body medicine.

Simply put, the human stress response has three basic components.

The first is the catecholamine, or fight-or-flight response, and it kicks in as soon as we are threatened.

The second is the response of the HPA axis. HPA stands for hypothalamic-pituitary-adrenal axis. When faced with a threat, the HPA axis responds with a cascade of chemicals, the final one being the stress hormone cortisol.

The third component is the immune system’s response. When faced with danger, the immune system increases inflammation by releasing molecules known as proinflammatory cytokines. Cytokines are basically messenger molecules of the immune system. Inflammation has a very important role in protecting your health. These molecules protect you against infection and heal wounds. But when levels of these cytokines continue to be high, they can actually damage your body.

A key finding in mind-body research is that psychological stress can trigger the inflammatory response.

You’ll notice that I’ve drawn this three-component response with arrows connecting each component. In a normally functioning system, these three components serve as checks and balances to each other. When one part gets too high, the others activate to lower it. The problem is that when this system is overloaded, as it is in stress and depression, the components no longer serve as checks and balances. Instead, they start actually enhancing the negative effects.

Fortunately, there are some steps you can take to lower your response to stress. And that is what we will talk about in the next few posts.