Can Fear Sabotage Our Immune System?

Fear is a natural human emotion that is triggered by a perceived threat. While fear can be useful in some situations, such as when it helps us avoid danger, excessive or chronic fear can be harmful to our physical and mental health. In particular, fear can have a negative impact on our immune system, which is responsible for protecting us from infections and diseases. In this article, we will explore five ways that fear can sabotage our immune system.

1. Fear activates the stress response

Fear triggers the release of stress hormones, including cortisol and adrenaline, which are part of the fight-or-flight response. This response is a natural and adaptive physiological response to a perceived threat that is necessary for survival. However, when the stress response is chronically activated, such as in the case of fear or anxiety, it can lead to a state of prolonged stress that can negatively impact the immune system.

Research has shown that chronic stress can suppress the activity of immune cells and impair their function, leading to a weakened immune response (Dhabhar, 2014; Glaser & Kiecolt-Glaser, 2005). For example, stress can impair the function of natural killer (NK) cells, which are a type of immune cell that play a crucial role in detecting and killing virus-infected and cancerous cells. Chronic stress can also lead to a decrease in the production of cytokines, which are proteins that help to coordinate the immune response to an infection.

Moreover, the stress response can also cause a shift in the type of immune cells that are produced, with a greater production of immune cells that promote inflammation and a decrease in those that are anti-inflammatory (Dhabhar, 2014). This shift can lead to chronic inflammation, which is associated with a range of diseases, including heart disease, cancer, and autoimmune disorders.

2. Fear can disrupt sleep

Fear and anxiety can make it difficult to fall asleep and stay asleep. This can lead to sleep deprivation, which has been shown to have a negative impact on our immune system.
During sleep, the body produces cytokines, which are proteins that help to coordinate the immune response to an infection (Besedovsky et al., 2019). Cytokines are necessary for recruiting immune cells to the site of infection, and for activating those cells to fight off the infection. Sleep deprivation can reduce the production of cytokines, which can make it more difficult for the body to defend against infections.