How Fear Sabotages Your Immune System

For more than three years, the world has been plagued by the COVID-19 pandemic, which has profoundly changed our society and many people’s lives. For instance, people have become more fearful in general during the pandemic, which in turn sabotages their immune systems and makes them more vulnerable to COVID-19 infection.

According to a study by a team of researchers from the University of Rochester that examines people’s mental health concerns during the pandemic, fear was the most prevalent mental health symptom during the COVID-19 pandemic.

The most prevalent mental health symptoms during COVID-19. (The Epoch Times)

The word “fear” was also the most frequently mentioned in social media, followed by keywords such as “alone,” “failure,” and “depress.”

Different types of fear were prevalent during the pandemic, including fear of death, loss of family/friends, vaccine adverse events, COVID infection, and long COVID. For instance, while some people were trying to stay away from COVID-19 vaccines, some were afraid of “missing out” on the most effective brand by choosing the “wrong” ones. Several other forms of fear include panic and phobia.

Some people were afraid of the COVID-19 infection. As a result, when COVID-19 vaccines became available, they received four to five doses, including booster shots. These people also wore N95 masks and strictly observed social distancing rules. Even with masks, they were fearful of entering a crowd to perform daily duties, such as grocery shopping.

Others were concerned about vaccine side effects and adverse events. They might have elected to get vaccinated as a requirement to stay employed, but they still kept worrying over the potential side effects, such as myocarditis.

These heightened fears may negatively impact people’s health in many different ways, and fear’s effects on our immune system can be detrimental.

A Bout of Fear Can Temporarily Boost Our Immunity

Fear, the unpleasant emotion that comes in response to danger, is a necessary bodily mechanism essential to our survival. In the short term, fear can actually boost our immunity.

When we sense that danger is imminent, fear sends our body into the “fight or flight” mode, which equips us with the necessary energy to either flee the danger or prepare for a fight. Fear makes us more vigilant and take protective measures that we deem useful in response to a threat like COVID-19.

Our immune system also increases its antiviral activity when we perceive a risk of COVID-19 infection. Our brain’s amygdala will alert our nervous system. Our pituitary and adrenal glands will then increase the production of stress hormones, such as cortisol and adrenaline, and circulate them in the blood.

Cortisol is generally anti-inflammatory, and it makes glucose more available to the muscles and brain. Adrenaline, also known as epinephrine, can increase the heart rate and blood pressure, expand the lungs’ air passages, improve vision and other senses, and redistribute more blood to the muscles. Adrenaline can also increase the number of monocytes and neutrophils, both of which are white blood cells, and send them into the bloodstream, while sending another type of white blood cell called lymphocytes, into other tissues.

Why Fear Sabotages Our Immunity

Although a bout of fear can enhance our immunity and boost our chance of survival, being in a constant state of fear for a prolonged period can also create problems, such as the weakening of our immune system.

Stress hormones produced by fear can inhibit immune cells

Cortisol and adrenaline, though helpful for short vigilance, are actually stress hormones.

If a person has consistently high levels of cortisol, the body will eventually become used to having an excessive amount of cortisol. According to a study recently published in the journal Brain Sciences, such chronic elevation of cortisol can lead to increased activation of inflammatory cytokines and promote insulin resistance. And the worsened insulin resistance situation will in turn contribute to more inflammation. These incidents can lead to chronic inflammation of the body and a weakened immune system.

Consistently high levels of adrenaline, as well as cortisol induced by fear, can weaken the body’s immune system because of their inhibitory effect on many immune cells. Cortisol is the primary glucocorticoid. Glucocorticoids significantly reduce the number of circulating immune cells, including T cells and macrophages.

In one study published in the journal Brain, Behavior, and Immunity, one group of people who have the trait of worry was exposed to a phobic stimulus, while another group with the same trait was not exposed. The results showed that both groups experienced increased heart rate, but the group that was fearful due to the stimulus didn’t have an increase in natural killer cells—a kind of immune cell—in their peripheral blood, while the other group did.

In addition, in a study published in the journal Nature, the authors found that the brain’s fear circuit could regulate immune cells during acute stress.

Our “fear circuitry” is mainly composed of the amygdala, nucleus accumbens, bed nucleus of stria terminalis, hippocampus, and ventromedial hypothalamus. According to an article published in the Journal of Neuroscience, although fear and anxiety are distinct emotions, they share the same underlying neural circuitry, as fear is a negative emotional response to a certain threat, while anxiety is the response to an uncertain threat.

The researchers of the study published in Nature discovered that during acute stress in mice, different brain regions shaped the distribution of immune cells and the function of the entire body. For instance, the researchers found that acute stress redistributed immune cells from peripheral organs, such as muscles and blood vessels, to the bone marrow, and the number of B cells (important to the adaptive humoral immune system) and T cells in the lymph nodes was also reduced.

Furthermore, researchers found that acute stress altered innate immunity by directing neutrophil recruitment to sites of injury.

Fear affects the endocrine system, which can lead to hormone problems

When fear initiates the fight-or-flight response, the amygdala signals the hypothalamus to activate the pituitary gland, which is considered the “master gland” of the endocrine system, as it also controls many of the other glands. The endocrine system (aka, hormone system) is composed of glands that produce hormones to regulate many of our bodily processes, including our mood, energy level, blood pressure, appetite, and immunity.

Since our hormones directly affect the strength of our immune system, which works hand in hand with the endocrine system, a hormone imbalance caused by constant fear can indeed sabotage our immunity. The major hormones that can have a significant impact on our immune system include steroid hormones (e.g., estrogen, testosterone, progesterone, prolactin, and glucocorticoids), oxytocin, and serotonin.

For instance, estrogen has been shown to boost women’s immune systems, as their immune systems are generally the strongest during their reproductive years when estrogen is at its highest level. As testosterone generally inhibits the immune system, it’s quite possible that women tend to have a higher prevalence of autoimmune disease than men, due to the estrogen in their bodies. Autoimmune conditions can sometimes relate to hormone imbalances.

Therefore, fear can cause a hormone imbalance, which in turn can lead to problems with the immune system.

Fear Can Cause Other Illness

1. Fear of symptoms can actually cause them to occur

In a study of adjuvant chemotherapy, which was published in the World Journal of Surgery, 40 participants (31 percent) of the control group, who received a placebo injection, developed alopecia. Cancers don’t usually cause hair loss, but alopecia affects approximately 65 percent of patients who receive cancer treatment. Therefore, such a high percentage of alopecia among the control group suggests that it was their fear of chemotherapy side effects that caused the hair loss to occur.

2. Fear makes the body unable to switch to the ‘rest-and-restore’ mode

Constant fear can make the body stuck in the fight-or-flight mode, which is controlled by the sympathetic nervous system of the autonomic nervous system. As a result, the body cannot enter the “rest-and-restore” mode, which is controlled by the parasympathetic nervous system. This system helps the body stay in equilibrium by activating more restful functions, such as decreasing the heart rate and relaxing the muscles.

So if fear over the long term prevents the body from entering the rest-and-restore mode, the body cannot relax or rest, and diseases can eventually result.

3. Fear causes sleep disruption and food deregulation

When people are in a fearful state of mind, they tend to have poor sleep quality. This lack of quality sleep can lead to several chronic diseases and conditions.

When some people feel fearful, they want to eat sweet and fatty foods full of additives, which can cause the body to have inflammation, if consumed over the long term. Also, the consumption of unhealthy foods can damage the gut microbiome, and 70 percent of our immune system is located in the gut.

4. Long-term fear can cause other conditions

Constant fear can induce anxiety, hypochondria, high blood pressure, asthma, and depression. Since fear can affect our neuro-endocrine-immune system, it also has an impact on our growth and development, as well as reproductive, urinary, and respiratory functions.

Furthermore, fear can create toxins in our brain that make it foggy and prevent it from functioning at its best. Thus our brain cannot pay attention to our body’s health as it should, such as forgetting to take medicine on time.

3 Ways to Mitigate the Negative Effects of Fear

Since fear has so many aforementioned negative impacts on our bodies, especially our immune systems, we need to find ways to mitigate these effects.

1. Face fear head-on and release negative feelings

In her book “Radical Remission: Surviving Cancer Against All Odds,” researcher and lecturer in the field of integrative oncology Kelly Turner, holding a doctorate in social sciences research, mentioned an alternative healer’s perspective on fear. This healer is Patti Conklin, who holds a doctorate in humanities and divinity; according to her, fear is a dominant emotion for most cancer patients.

According to Conklin, a patient should face fear head-on in order to release it. One example mentioned in “Radical Remission” is about a man named Nathan, who was diagnosed with a rare form of stage 4 lymphoma. Unfortunately, instead of eradicating it, several rounds of chemotherapy made his cancer grow. As a result, he decided to stop the treatment, and his doctors informed him that he only had one to two years to live. He didn’t sleep for four days, fearing death.

Eventually, he decided to face his fear and accept the fact that he was going to die. To his surprise, once he made the acceptance, his fear was gone.

When he sat down to be interviewed by Turner six years later, he had been traveling, enjoying natural sceneries, and receiving help from alternative healers. He had outlived his doctors’ predictions by at least four years.

2. Replace fear with positive feelings 

Another effective way to deal with fear is to replace it with positive emotions, such as gratitude and happiness.

According to one study published in the journal Brain, Behavior, and Immunity, gratitude can bring health benefits in women, and increases in support-giving were associated with reduced amygdala activity.

The participants in the study were asked to perform a gratitude task. After the completion of this task, those who showed larger reductions in amygdala activity also experienced larger reductions in the production of pro-inflammatory markers, including tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6). By replacing fear with gratitude, the immune system improved.

Replacing fear with gratitude can improve immunity. (The Epoch Times)

3. Boost immunity

Sometimes, fear is inevitable, though one may try to release or replace it with another emotion. In this case, we can focus on boosting our immune system, which can somewhat offset the negative effects brought by fear.

Ways to improve our immunity include but are not limited to maintaining a healthy diet with lots of proteins and vegetables, being physically active and avoiding a sedentary lifestyle, keeping fit with a healthy weight, getting sufficient high-quality sleep, and quitting or avoiding smoking and alcohol consumption.