The link between stress and inflammation

 by Liesa Huppertz
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We all experience stress in our lives whether it is due to high job demands, low-income, problems at home or at work or minor things like a computer breakdown or a traffic jam. While a little stress is certainly harmless, research shows that long-term stress can lead to a number of chronic conditions. For a very long time the pathways between stress and disease remained unclear. Now studies point in the direction of inflammation as the real culprit. (1)

Research shows that chronic stress can lead to inflammation in the body which is the cause for many serious diseases - some of them even deadly. In fact, 75 - 90% of human diseases is related to the activation of our stress system. The author of the study “Inflammation: The Common Pathway Of Stress-Related Disease” states that “chronic inflammation is an essential component of chronic diseases.”

In the last two decades, accumulating evidence indicated that severe or prolonged (chronic) stress resulted in increased risk for physical and psychiatric disorders, which is called stress-related disease. The most common stress-related diseases are cardiovascular diseases, metabolic diseases, diabetes and non-alcoholic fatty liver disease (NAFLD), psychotic and neurodegenerative disorders (i.e. depression, Alzheimer’s disease, AD and Parkinson’s disease), and cancer.

In this article, we are going to talk about the link between stress and inflammation and how it may lead to disease. We will talk about the most common diseases that derive from stress and how we can manage our stress-levels effectively.

What is chronic inflammation?

Before we answer the question of what chronic inflammation is, let’s look at inflammation in general. Inflammation is your body’s normal response to injury, infection or any other invader. It is not a bad thing, quite the opposite, actually. It is your body’s way of protecting itself by releasing inflammatory cells that promote healing of the tissue. The affected body part might swell up, turn red and hurt. You may even experience a loss of function or heat. These are symptoms of acute inflammation.

Unfortunately, inflammation doesn’t always help the body. Sometimes inflammation doesn’t subside and the body starts to attack its own cells without any obvious reason, causing harmful inflammations. We are going to talk about some of the diseases caused by chronic inflammation in this article. These include, for example:

  • Rheumatoid Arthritis
  • Inflammatory Bowel Disease
  • Cardiovascular Diseases

Symptoms of these chronic inflammatory diseases can go for years or even a lifetime without being noticed which makes chronic inflammation extremely dangerous.

What is stress and what does it do to our body?

Stress is a state of threatened homeostasis provoked by a psychological, environmental, or physiological stressor. (1) It is not necessarily a bad thing - in fact, our ancestors wouldn’t have survived without it. They used the onset of stress to alert them of potential dangers such as wild animals.

Stress is primarily a physical response. Your body thinks it is under attack and goes into the so called fight or flight mode. To prepare the body for action, a complex mix of hormones and chemicals such as cortisol, adrenaline and norepinephrine is released.

The release of hormones results in a rush of energy, which prepared the cavemen to either fight or flee the scene. Have you ever noticed how your heart is pounding and your breath fastens when you’re nervous or scared? That’s the effect adrenaline has on us. It tells the body to increase heart and respiratory rate, and to expand airways to push more oxygen into your muscles. Together with a boost of energy to the large muscles, it enables you to focus all of your attention on the danger ahead so that you can respond to it quickly.

At the same time, the body directs resources away from functions that aren’t crucial in life-threatening situations such as digestion or reproduction. The immune system, too, is being suppressed.

However, even though we are not battling with wild tigers anymore, the fight or flight mode is still useful in dangerous situation today, for example when the person in the car in front of you slams on the brakes and you need to react quickly.

Chronic inflammation and stress

The problem with stress is that it is meant to be short term and adaptive, which totally makes sense: When you’re in fight or flight mode your normal immune functions shut down. Your body focusses all of its attention and resources on the threat ahead to enable you to fight or flee for your life. You don’t want to be occupied with digesting the last thing you ate then or sending immune-fighting cells to kill a cold virus. If we are, however, kept in a state of stress for long periods or stress even becomes chronic, it can be detrimental to our health and set up the cascading inflammatory response.

Chronic stress and the inflammation associated with it are suggested to be underlying factors in most chronic diseases. In fact, the most common stress-related diseases are cardiovascular diseases, metabolic diseases, diabetes and non-alcoholic fatty liver disease (NAFLD), psychotic and neurodegenerative disorders (i.e. depression, Alzheimer’s disease, AD and Parkinson’s disease), and cancer (2). Chronic stress as well as inflammation are all the more dangerous, because the symptoms are overlooked so easily and before the first signs of the disease appear, years can go by.

We have to understand that evolution didn’t equip us to live in a constant state of stress. The fight or flight mode is there to help us survive temporary, immediate threats. However, today we face little of the threats our ancestors had to stand up to. Still, our stress mode doesn’t seem to come to a stand still.

Once the full-blown stress response is set in motion, there is little we can do to override it. The adrenal glands start to release hormones, e.g. adrenaline and cortisol. By latching on the specific receptors on cell membranes, immune cells are activated and when this happens, these immune cells start to prepare against the enemy. Through disturbing the balance of the immune system, stress induces inflammation peripherally and centrally. (1) For example, research showed that stress can lead to the release of white blood cells from bone marrow that are more inflammatory than normal upon release, just as though they are ready to defend the body against harm. (3) Now normally, when you cut your finger or fight a cold, this reaction is favorable. However, when this happens and the inflammation doesn’t have any protective or healing role, the imbalance in immune cells can lead to diversified stress-related diseases such as diabetes, obesity, an increased risk for cardiovascular diseases and other disorders.

For example, asthma, a chronic (long-term) disease, is another illness associated with psychological stress and inflammation. Studies found that “psychological stress can exacerbate clinical symptoms in patients with asthma by altering the magnitude of the airway inflammatory response that irritants, allergens, and infections bring about in persons with asthma.” (4)

Depression is another condition associated with stress and chronic inflammation. A study published just recently in 2019 found that “psychological stress triggers inflammatory activity and affective-cognitive changes that play a critical role in the onset, maintenance, and recurrence of depression.” (5)

While the common pathways between stress exposure and pathophysiological processes underlying diseases is still debatable, researchers stress the link between chronic inflammation, stress and disease (1). In fact, only 5 percent of people with a particular genetic change (e.g. a mutation in a specific gene) exhibit signs and symptoms of a genetic disorder (6). That means that we have the ability to influence the expression of 95 percent of disease-related gene mutation, including genes for cardiovascular disease, Alzheimer’s disease, diabetes, and many types of cancer. Thus, we need to protect our genes and optimize our lifestyle behaviors.

Chronic conditions linked to stress and inflammation

More and more research indicates that severe or prolonged (chronic) stress results in increased risk for so called stress-related diseases (1). We have already briefly talked about the connection between stress, inflammation and depression as well as stress, inflammation and asthma. However, there are many more chronic diseases that seem to have their origin in chronic stress. Let’s look at some of them.

  • Cardiovascular Disease: Cardiovascular disease is probably one of the most famous stress-related disease. It is considered to be the leading cause of death worldwide. Researchers found out that chronic stress has long been linked to increased coronary heart disease risk (1). What’s more interesting is that even early life stress, especially severe physical and sexual abuse in childhood, was found to strongly relate to higher morbidity of cardiovascular events in women (7). In adulthood, stress at work, e.g. low-income, high job demands, shift work and workplace conflicts seem correlate with higher cardiovascular disease risk (1).

The link between stress and cardiovascular disease may not be very well known yet, however, researchers hold chronic low-grade inflammatory load responsible for the early process, progression and thrombotic complications of atherosclerosis, a precursor to heart disease. The two important biomarkers of systemic inflammation, Interleukin-6 and CRP, are considered to be indicative and potentially predictive for atherosclerosis. Interestingly, these two inflammatory markers were also elevated in different types of life stress. (1)

  • Rheumatoid Arthritis (RA): Rheumatoid Arthritis is a disease in which the body’s immune system attacks joints and tissues, leading to stiffness and pain. Inflammation seems to be the leading factor behind RA caused by pro-inflammatory cytokines, chemicals that are released when we’re stressed. Thus, the more stressed we are, the more cytokines are being released, leading to even more inflammation. Therefor it seems like cytokines are the main molecules contributing to all facets of the disease. (8)

  • Inflammatory Bowel Disease (IBD): IBD is a term for two conditions - Crohn’s disease and ulcerative colitis - that are characterized by chronic inflammation of the gastrointestinal (GI) tract. Long-term inflammation then results in damage to the GI tract. Psychological stress seem to increase disease activity in IBD through stress induced alterations in gastrointestinal inflammation. (9)

Strategies to reduce stress and decrease inflammation

We have seen how stress impacts inflammation and how inflammation in turn may lead to chronic diseases such as Cardiovascular Disease, Rheumatoid Arthritis, cancer and even obesity. If that shows us anything it is how important it is to manage our levels of stress.

There are many research-backed ways to reduce our stress, meditation and yoga being among the most popular ones.

A study published in 2016 showed that experienced meditators have lower cortisol (a stress hormone) levels as well as a smaller neurogenic inflammatory response, compared to the control group. Furthermore, higher levels of psychological factors associated with wellbeing and resilience were reported by experienced meditators.

Yoga seems to be able to bring about similar effects in decreasing levels of cortisol and inflammation, as a study published in 2017 showed . A meta-study from 2013 came to similar results, showing that from 17 studies, 12 demonstrated positive changes in psychological or physiological outcome measured related to stress.

Although the same stress-reduction technique might not work for everyone, it is important to find one that suits your needs. Once you have started using that specific technique, one thing is important: don’t expect miracles. Every form of stress reduction requires a great deal of patience as we have to unlearn our previous response to stress and replace it with healthy ones.

Other stress-reduction methods include:

  • Mindfulness
  • Journaling
  • Being outdoors in nature
  • Deep Breathing
  • Use of Essential Oils

A continuous practice of (one of) these techniques will help you manage your stress effectively and lower your risk for chronic diseases and psychiatric disorders.

We're all aware that stress isn't good for our health. But did you know just how detrimental it can be? Learn about the link between stress, inflammation & disease and what to do about it!

Disclaimer: Please be aware that I am not a doctor or a medically trained person. What you're reading here is information that I researched and summarized to the best of my knowledge and processed it for your digest. Information stated on iamliesa is for educational purposes only, this information is not to replace advice from your health care practitioner. If you have any concerns about your health, always consult your general practitioner.

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