Discuss a biological approach to understanding one health problem Flashcards
Stress
The process that arises when the perceived demands on an individual exceed a person’s capacity and capability to cope with those demands
What can stress be considered as?
Stress can be considered as both the state of this imbalance and the effects it has on someone as their body and mind respond to this state.
Stress in an evolutionary perspective
From an evolutionary perspective, stress arises as the result of an acute threat and its paired response, such as fighting or running for one’s life.
When a stressor and its response last for more than an isolated experience or a couple of weeks, they can become chronic stress, and this type of stress can contribute to the development and progression of non-communicable diseases.
Relying just on the biological approach alone is what?
Relying on the biological approach alone is seen as reductionist, ignoring both cognitive and sociocultural factors that may play a role.
A key model to explain stress and how it leads to health problems
General Adaptation Syndrome (GAS) proposed by Hans Selye
What did Selye view stress as?
As the body’s attempt to adapt to a stressor.
Usefulness of stress but the issue with it as well
This adaptation protects the body in the short term. But if the stressor is prolonged serious damage can occur.
What are the 3 stages of GAS?
Alarm reaction
Resistance
Exhaustion stage
Alarm reaction
when a stressor is perceived, the immediate physiological response is shock.
At this time the body’s resources are briefly decreased before quickly recovering.
Physiological systems are activated in preparation for the fight or flight.
Resistance
Where the body attempts to adapt to the stressful environmental demands by resisting the stressor. Physiological activity is greater than normal and uses a lot of energy.
The individual appears to be coping but the body’s resources are being consumed at a potentially harmful rate.
Exhaustion stage
Where the adaptation to a chronic stressor is now failing. The body’s resources are drained and therefore the resistance plummets. The immune system therefore becomes compromised and stress related illnesses are likely to come such as depression.
A study that supports the GAS
Cohen
Aim of Cohen
Carried out a study to see if stress leads to colds
Procedure of Cohen
He gave participants tests to determine their overall general health and their recent exposure to stress.
He then exposed participants to either a cold virus or to a simple saline solution, which served as the placebo.
Participants were then quarantined for five days. They were checked daily for any sign of illness.
Results of Cohen
The researchers found that the duration and nature of stress that an individual experiences is a strong predictor of who gets a cold.
Those who had high levels of stress for a month or more were over twice as likely to get ill as those who had no such stress.
The type of stress also seems to matter.
Participants who were unemployed were three times more likely to develop colds than those who didn’t have work-related problems.
And those who reported serious problems in their close relationships were 2.5 times more likely to contract viruses than those without such problems.
How does Cohen support GAS
As it supports that it was participants who were in the exhaustion stage that suffered the most from the cold and therefore links stress to health problems affecting it negatively.
How does Cohen also support the sociocultural approach?
It also supports that there is a sociocultural aspect that also plays a key role as it raises the chances of getting a cold.
This therefore supports that it is a combination of sociocultural and biological aspect that affects the effect of stress on the body.
Issue with Cohen
A key issue with the study however, is that there are serious ethical issues as the researchers purposefully exposed the participants to a cold which could cause harm and therefore may not be accepted as an acceptable study.
Issue with Cohen that Kiecolt-Glaser et al solves
Another issue is that even though it relates stress to potential disease, it doesn’t look at how stress actually leads to a decrease in our body’s ability to fight off disease.
To get more information on that, we need to turn to a classic study in psychology carried out by Kiecolt-Glaser et al.
Aim of Kiecolt-Glaser et al
To see if the stress of important exams could lead to a decrease in immune function.
Procedure of Kiecolt-Glaser et al.
The researchers tested participants for their level of stress before the experiment began.
They were also given a test to determine the life changes that occurred within the last year that would raise their level of stress.
Participants were then divided into groups depending on their stress and their level of loneliness.
NK cell activity was measured in the students’ blood sample.
NK cells are lymphocytes which provide rapid responses to viral-infected cells and determines the function of the immune system.
Results of Kiecolt-Glaser et al
There was a significant decrease in NK cell activity between the first blood test and the second blood test. Participants in the high stress group were more likely to have lower levels of NK than those in the low stress group.
This means that stress experienced previous to the exams played a role in their immune systems’ ability to cope with the stress of examinations.
In addition, participants in the “high loneliness” group had lower levels of NK than those in the “low loneliness” group.
Conclusion of Kiecolt-Glaser et al
This confirms the role of social support as a protective factor for better health.
Kiecolt-Glaser concluded that stress has a direct effect on the immune system by suppressing NK cell activity.
It therefore determines that the cause of a reduction in health is due to NK cell activity.
The research seems to support the General Adaptation Model proposed by Selye.
As our body continues to cope with stressors, it eventually becomes “exhausted.”
In this exhausted stage, this is when we are most likely to become ill.
Issue with the Kiecolt-Glaser study
However, one of the problems of the experiment is the age of the participants.
Students are often used in psychological research because they are easy to find and usually willing to participant in research studies.
However, younger people usually have stronger immune systems than older people.
Therefore, it is difficult to generalise the findings to older people.
In addition, the stress of exams is an acute stressor.
It is not like poverty or constant noise pollution.
More research needs to be done on the extent to which the nature of the stressor itself may - or may not - have an effect on the immune system.
Another factor that determines the effect of the GAS on individuals
HPA axis
HPA axis
The process of the secretion of hormones in the brain when we appraise an event as stressful
One of the main hormones released by the HPA axis
Cortisol
Cortisol useful
Useful for when an individual is in a flight or flight response as it increases the glucose level for more energy and reduces the functioning of processes in the body that are not essential.
Cortisol not useful
However, when there is too much it can lead to negative effects on the body and therefore supports the GAS.
A study that supports the effect of the long effects of cortisol which link to the exhaustion stage of GAS
Sapolsky
What did Sapolsky investigate?
Wanted to investigate the social hierarchies in baboons
Procedure of Sapolsky
Sapolsky would take blood samples of baboons over a period of time to find which baboons would have the most.
Findings of Sapolsky
He found that baboons in low hierarchies had the most.
During a prolonged period of time, he found that high cortisol lead to hypertension and elevated heart rates and well as high levels of cholesterol, leading to atherosclerosis.
He also found that high levels of stress inhibit reproduction in both genders.
How does Sapolsky support GAS?
This therefore supports the GAS and its evidence for the negative effects of cortisol and the exhaustion stage on animals.
Issue with Sapolsky
However, the issue is that this study is on baboons and not humans and therefore it is difficult to generalise the findings to humans.
Conclusion of Biological approach
Therefore, the studies strongly support the GAS approach to stress and how it leads to high health problems. However, seeing the biological approach as the only factor would be reductionist and incorrect as Cohen and Sapolsky support that the sociocultural approach also has a strong effect.
