Stress is a response in the body that enables us to run, take down prey or run from predators, also known as the flight-or-fight response. Unfortunately, many of the same life-saving reactions your body uses to protect you from danger may also be triggered as a response to cope with the rising prices of gasoline, a fear of public speaking or dealing with difficult bosses.
In other words, the body sometimes has a difficult time turning stress off. The good news is there are several strategies you might consider to relieve the response and reduce the negative health effects if you are dealing with a lot of psychological or physical stress. However, while TV commercials and other advertising may insinuate that we should all be living in a perfect world, in truth, a world without stress may kill you.
According to Psychology Today,1 stress is the perceived disconnection between what is happening and your resources to deal with the situation. This means stress could be a real or imagined threat since the operative word is perceived.
Psychologists say too much is toxic but a little is needed for mental and physical resiliency.2 For instance, without societal stress to do well in school, students may not study or show up for class. However, major stressors may be debilitating, such as caring for someone with a chronic or debilitating disease or losing your job.
Researchers have also found mild physical stress may help improve development. A team from Johns Hopkins University3 followed 137 pregnant women and followed up with their 2-year-old children. They found a mild amount of anxiety and stress during pregnancy was associated with more advanced physical development in their children.
The researchers found prenatal maternal stress did not impact the child's temperament, attention or their ability to control behavior.4 As with most biological processes, there is a balance, as too much has a negative impact and too little may not offer enough challenge to bodily systems.
Chromatin key to stress response and longevity
Recent research from the Stowers Institute for Medical Research found that chromatin stress triggers a cellular response that may lead to a longer life. In order for an organism to survive, they must be able to adapt to changing conditions. The cellular response dedicated to this affects how the genome is structured.5
Inside cells that contain a nucleus, DNA is packaged with histone proteins to create a structure known as nucleosomes, which are further condensed into chromatin.6 The overall packaging determines the expression of your genetic code. This expression is impacted by environmental stress.7
Everything involved in reading your DNA must deal with the chromatin structure, according to scientists from the Baylor College of Medicine.8 Corresponding author Weiwei Dang9 explained that when a particular gene is expressed, enzymes will interact with the chromatin to negotiate access in order to translate the information into specific proteins.
With chromatin stress, the disruption may also lead to unwanted changes in genetic expression. During this study, the team worked with yeast to determine how histone genes would affect longevity.10 The team deleted histone H3-H4 minor locus HHT1-HHF1,11 unexpectedly finding that with this reduced number of genes, the yeast replicated longer.
The response to chromatin disruption in the yeast changed the activation to genes that eventually promoted longevity of the yeast cells. This stress occurred in other organisms as well, including a laboratory worm and fruit fly as well as mouse embryonic stem cells, all promoting longevity.12
Mitochondria produce energy and sustain life
Your mitochondria have enormous potential to influence your health. They are essentially tiny powerhouses found in most of the cells in your body. They form an interconnected network allowing the distribution of energy.13
Mitochondria work by transferring electrons from fat and sugars into oxygen during the process of generating adenosine triphosphate (ATP). This is the “energy currency” used by your body’s cells.14
Mitochondria are unique in that they have their own genetic code different from nuclear DNA,15 known as mitochondrial DNA (mtDNA). They also have cellular, molecular and behavioral responses to stress that require more energy.16
Mitochondria intersect psychological and biological stress
During stress, mitochondrial function changes to guard against disease as you age. One stress response pathway in the cells is called the unfolded protein response (UPR) with several divisions that handle a number of functions at the cellular level.17
Changes in DNA expression are affected by the structure of chromatin.18 One study19 demonstrated that enzymes that modify histones have a significant role in the UPR response. By using genetic screening, the team found the LIN-65 gene was important to the induction of mitochondrial UPR to extend lifespan, but it occurred even in the absence of LIN-65, which could mean there were other pathways.
As well as being important to increasing longevity, the mitochondrial stress response may also be “an intersection point between psychosocial experiences and biological stress responses.”20 In a review of 23 animal studies, it was noted that the evidence indicates acute and chronic stress influence mitochondrial biology.
Maladaptive changes in the mitochondria called mitochondrial allostatic load,21 are potentially able to convert psychosocial experiences into physiological changes.22 This understanding has far-reaching consequences.
Chromatin remodeling may affect physiological change
For instance, in one study23 researcher found initial evidence that different types of interactions with infants and young children generate differences triggering chromatin remodeling. This gives us one possible explanation for why molecular changes in early development result in lifelong emotional responses.
Researchers hypothesize this may provide insights into how experiences move from external stimuli to internal biological changes through chromatin remodeling and then emotional changes as an adult.24 In other words, mitochondrial stress changes chromatin early in life and may have a significant impact on later development.
An animal study25 from Children's Hospital of Philadelphia showed how alterations in mitochondria could lead to physiological changes in response to mild stress.
This also affected how the mammals responded to changes in their environment and may have profound implications on the idea that neuropsychiatric diseases are hereditary. Researchers find the implication in this study may suggest new therapies for neuropsychiatric diseases and make people more resilient to environmental changes.26
Exercise stress produces beneficial mitochondrial change
Since mitochondria supply energy for growth and development, this means they are responsible for the lifespan of most cells. A buildup of the remnants of proteins and oxidative damage, among other things (known as “debris”), drives biological aging, chronic inflammation, and cell deterioration.27
In one study28 from Mayo Clinic, 72 men and women were split into younger and older groups and then further split into three exercise programs: high intensity, strength training, and a combination. The researchers’ goal was to evaluate exercise stress on gene transcription and mitochondrial respiration.
At the end of the experiment, biopsies were taken from participants’ thigh muscles and the molecular makeup was compared against those from members of the control group. The control group had not been exercising. Researchers discovered29 that strength training may build muscle but high-intensity interval training (HIIT) has the most value on a cellular level.
HIIT exercise appeared to minimize damage to mitochondria from the accumulation of debris as we age.30 Those who were in the HIIT group experienced greater insulin sensitivity but less growth of muscle strength.
The younger participants taking part in the interval training experienced up to a 49% increase in mitochondrial capacity, but it was the older participants who experienced a more dramatic response of a 69% increase.31
Physical stress also affects brain tissue
Another research group undertook an animal study32 to determine if some of the same mitochondrial benefits experienced in skeletal muscle happened in brain tissue. They believe the results of their study suggest exercise training, even in older mice, could improve neurological mitochondrial function.
The results of these studies support a past paper33 in which the authors proposed that while advancements have increased life expectancy, knowledge of what's happening on the molecular and cellular level may extend maximal lifespan.
In reviewing the literature, they found a common thread emerging in experiments using plants and animals: The regulation of life and aging is in the mitochondrial system. Additionally, decay may be counteracted with physical activity and regular aerobic exercise may increase or prolong life at the mitochondrial level.34
Dietary factors promote mitochondrial longevity
Past research35 involving lab animals has demonstrated that limiting calorie intake has a positive impact on realizing a longer lifespan. Manipulating mitochondrial networks through fasting or genetic manipulation has demonstrated the ability to increase lifespan.
A study36 by a Harvard research team investigated the basic biology involved and how dietary restriction promotes healthy aging. The researchers used nematode worms. These worms have a normal lifespan of just two weeks and allowed the team to study lifespans in real time.37
Restricting the worm’s diet, or genetically altering their mitochondria, kept the mitochondrial network in a more youthful state and increased the worms’ lifespans. The researchers believe their results demonstrate how the flexibility of mitochondrial networks is used in a fasting state to lengthen a person’s life.38
Scientists who conducted a different study39 evaluated the damage done by a dietary overload on mitochondrial function, which may lead to premature tissue aging. They designed weekly schedules of fasting and demonstrated it was effective in limiting mitochondrial damage.
The test subjects’ tissues were able to maintain efficient mitochondrial respiration in skeletal muscle and showed an improvement in blood glucose profiles. The team concluded40 fasting might represent an effective strategy to limit mitochondrial impairment and improve metabolic flexibility, which is not found in those who typically consume a western diet.
Strategies to mediate the overwhelming stress response
Although a slight amount of stress helps your mitochondria stay healthy and lengthen your life, overwhelming stress has the opposite effect. Excess stress plays a role in negatively affecting your immune system, gut health, emotions, and sleep.41
Stress is one of the biggest challenges facing many U.S. adults,42,43 negatively impacting mental and physical health.44 The American Psychological Association’s 2015 Stress in America survey45 revealed a sizable number of adults do not feel they are doing enough to manage their stress.
Stress levels are also rising as 25% in 2015 said they felt over the past month “fairly often” or “very often” problems were piling up so high they couldn’t overcome them, compared to 16% in 2014. On average, those who reported having emotional support experienced lower stress levels than those who reported no emotional support.46
While a little stress helps your body to accommodate to change and increases your longevity, overwhelming stress may affect your mental and physical health.