For months, I had suspected that stress had helped trigger my disease. This thought was based mainly on personal experience–I had been incredibly stressed in the two years before colitis–and on the vague understanding that stress is linked to illness. Then, when I read Donna Jackson Nakazawa’s The Autoimmune Epidemic, I found a satisfying scientific narrative that fleshed out my vague knowledge.
To explain the basic mechanism by which stress affects our immune systems, Nakazawa first describes our bodies’ normal stress response. This response starts in the hypothalamus–a brain region that “works as a kind of on-duty internal alarm system.” At the first sign of stress, the hypothalamus triggers the release of both adrenaline and the stress hormone cortisol.
In a short-term stressful situation—when you suddenly have to veer away from an oncoming car on the highway, or leap to scoop up a toddler who is about to tumble down the stairs, or flee from a house that’s on fire—cortisol is critical to survival, preparing us for “fight or flight…” When the stressful event ends, your adrenals send the message back to your hypothalamus to tell it to stop producing extra cortisol and adrenaline so that your heart rate, breathing, and perspiration levels can subside to normal. That’s how the stress response is meant to work: it gets turned on when needed—and then it gets turned off quickly.
But problems occur when stress is chronic and does not turn off. “[U]nder chronically demanding conditions…heightened levels of cortisol are repeatedly pumped through the body.” We are not designed for the kind of chronic stress that’s common in the modern world, and this kind of stress can confuse our bodies’ systems.
One of those systems is immune function. Cortisol is central to this system:
Under stress, cortisol mobilizes all major types of immune cells to battle stations in the body… [W]hen stress turns chronic and an increased number of immune cells are ushered to sentry posts in the body too frequently, it can put too much wear and tear on the immune system. Overwhelmed by stress hormones and chemicals, immune cells never get a chance to recover… Our immune cells become so beleaguered that they become less able to react quickly to clear away pathogens—which is why research shows that you’re more likely to catch colds and infections if you’re in a troubled marriage.
Prolonged levels of heightened cortisol can not only lead to an underfunctioning immune reaction, but can also indirectly stimulate an autoimmune response… Cortisol helps to regulate our immune-system response not only by turning on the immune response, but also by turning it off. When cortisol keeps being pumped out because of daily anxieties and stressors, we stop producing sufficient cortisol to signal the immune response to turn off. This increases the likelihood that the immune system will go into erratic overdrive, that mistakes will be made and autoantibodies will attack the body itself.
In numerous studies, people who experience grinding, ongoing stress show higher levels of inflammatory cytokines in their blood compared to nonstressed individuals.
Paradoxically, reading this passage about how stress may have contributed to my illness, I experienced a sense of calm. It always calms me when I understand more about my illness, as if by understanding it better, I have more control over it. Knowledge is power.
And it was validating to find science and logic that backed up my experience. In the years leading up to my colitis, I had often felt the effects of cortisol coursing through my system, although I hadn’t called it “cortisol.” I had felt it as “stress” or “anxiety.” It was an all-too-familiar anxious urgency, not exactly a racing heart but a general quickening, an active background worry and the inability to relax. There was just always so much to do–cancer, wedding, politics, work… And it always felt so urgent, even after the busiest time subsided. Ron and I were fighting a lot in the year leading up to colitis. That year, too, my stress never seemed to fully subside.
Now, reading Nakazawa’s book, I suspected that my constant, anxious feeling had corresponded with a hyperactive stress response–and a chronically overworked immune system. Maybe, when doctors or websites said that stress doesn’t cause colitis, they were simply ignorant of the latest research. Because apparently autoimmune diseases could be triggered by chronic stress–and colitis is an autoimmune disease.