While stress may start in the mind, it can lead to acute or chronic disease promotion, such as increased susceptibility to infection from viruses, cardiovascular disease, cognitive decline and Alzheimer’s.
A stress steroid hormone, cortisol, which is released from the adrenal glands, can have beneficial effects in small bursts. Some of cortisol’s functions include raising glucose (sugar) levels when they are low and helping reduce inflammation and stress levels.
However, higher chronic levels of cortisol may cause inflammation.
Inflammation may be a significant contributor to more than 80 percent of chronic diseases. In a meta-analysis, high levels of C-reactive protein (CRP), a biomarker for inflammation, were associated with increased psychological stress.
A study of over 73,000 adults found that with CRP higher than 3.0 there was a greater than twofold increase in depression risk. The researchers suggest that CRP may heighten stress and depression risk by increasing levels of inflammatory communicators among cells.
In another study, results suggested that stress may influence the number of hematopoietic stem cells, resulting in an increase in inflammatory white blood cells. The researchers suggest this may lead to these white blood cells accumulating in atherosclerotic plaques in the arteries, which ultimately could increase the risk of heart attacks and strokes.
Chronic stress overactivates the sympathetic nervous system — our “fight or flight” response — which may alter the bone marrow where the stem cells are found. This research is preliminary and needs well-controlled trials to confirm these results.
Stress may increase the risk of colds and infection. Cortisol over the short term is important to help suppress cold symptoms, such as sneezing, cough and fever.
These are visible signs of the immune system’s infection-fighting response. However, the body may become resistant to the effects of cortisol. In one study of 296 healthy individuals, participants who had stressful events and were then exposed to viruses had a higher probability of catching a cold.
These individuals also had resistance to cortisol’s effects.
Lifestyle changes can reduce stress effects
Lifestyle plays an important role at the cellular level, specifically at the level of the telomere, which determines cell survival. The telomeres are to cells as the plastic tips are to shoelaces; they prevent them from falling apart. The longer the telomere, the slower the cell ages and the longer it survives.
In a study of women aged 50 to 65, those who followed a healthy lifestyle were able to withstand life stressors better since they had longer telomeres. This included regular exercise, a healthy diet and a sufficient amount of sleep.
On the other hand, those with poor lifestyle habits lost substantially more telomere length than the healthy lifestyle group.
In another study, chronic stress and poor diet (high sugar and high fat) together increased metabolic risks, such as insulin resistance, oxidative stress and central obesity, more than a low-stress group eating a similar diet. The high-stress group members were caring for a spouse or parent with dementia.
Interestingly, in terms of sleep, the Evolution of Pathways to Insomnia Cohort (EPIC) study shows that those who deal directly with stressful events are more likely to have good sleep quality. Using medication, alcohol or, most surprisingly, distractors to deal with stress all resulted in insomnia.
We need to recognize the effects of constant stress. If it’s not addressed, it can lead to suppressed immune response or increased levels of inflammation. To address chronic stress and lower CRP, it is crucial to adopt a healthy lifestyle that includes sleep, exercise and diet modifications.
Good lifestyle habits may also be protective against the effects of stress on cell aging.