Does stress cause cancer? Thus far, a direct connection cannot be definitively identified.
WHAT are the everyday stressors in your life? The traffic jams in KL would count as an important stressor. How about your boss? Do you feel stressed by her? In financial difficulties? Surely, that’s a major stressor.
Flash floods and electrical blackouts and brownouts are very inconvenient and stressful. This is made worse by pronouncements that they are an “act of God”. This whammy would further stress the believers and non-believers alike!
Apart from everyday stress, there are one-off stressful events. The death of a child is probably the most stressful event one can experience. The death of any loved one is terribly stressful. Divorce is stressful to most. Taking exams is stressful. Failing them is worse. Demotions and perhaps even promotions will stress you out. Moving house is bad.
Stress can cause mental health problems such as anxiety and depression. It can contribute to physical health problems such as high blood pressure and stomach ulcer.
Can stress also cause cancer, especially breast cancer, as many people believe? The argument goes like this. Stressful events can alter the level of hormones in the body and affect the immune system. Moreover many breast cancer patients recall a stressful event just prior to the initial diagnosis of the cancer or the diagnosis of a recurrence of cancer.
But the evidence for stress causing cancer has been poor. Most scientific studies have found that stress does not increase the risk of cancer.
The few studies that have linked stress and cancer had design flaws, including very small number of participants. Often, people with cancer will be asked to recall if they were stressed before they developed their disease. But these people are likely to overestimate their past problems to try and explain their condition.
The need to explain – any explanation at all – is a very innate human need. Many people would rather settle for an improbable explanation than accept that an issue is unresolved.
Stressful situations can make some people more likely to take up unhealthy behaviours such as smoking, overeating or heavy drinking. We know that these behaviours can lead to cancer.
In this way, stress could indirectly increase your cancer risk as well as the risk of other diseases. But it is very unlikely that stress can directly cause cancer.
A study carried out in Denmark and published in the British Medical Journal (September 10, 2005) had the objective of assessing the relationship between self reported intensity and frequency of stress and the incidence of primary breast cancer.
It was a prospective study (i.e. a better design than a retrospective study where there is a need to remember events of the past). A total of 6,689 women were followed from the early 1980s to 1999.
Women with a high level of stress actually had a 8% lower incidence of breast cancer! The researchers concluded that stress lowered the level of oestrogens, which are a known risk factor for breast cancer. That is not to say that we should purposely experience stress just to lower our incidence of breast cancer!
What can we make out of all these findings?
Firstly we should try to avoid the stressors in our lives. The cumulative health consequences of stress are dire.
Secondly, there is no direct link between stress and cancer. I tell my patients who report stressful events that they did not cause their breast cancer. I also try to assuage the guilt of relatives who think they caused cancer in their loved ones because of the perceived stress they inflicted upon the patient.
We are all enamoured by certain romantic notions about the world we live in. Many of us are in love with love and even more of us have faith in faith. Stress and de-stressing are much in vogue. It is fashionable to blame stress for any and everything, and cancer is not spared.
The scientific endeavour is an attempt to approximate the truth. We generate hypothesis, collect data, carry out experiments and form conclusions.
Some of these conclusions may not be in line with our popular notions and our world view. Of course, scientific conclusions are tentative and often counter-intuitive.
To understand these limitations of science is to understand its very essence and its strength.
Does stress cause cancer? Probably not. But it does all kinds of nasty things to you and it is best to avoid it.
Stress is basically a disconnection from the earth, a forgetting of the breath. Stress is an ignorant state. It believes that everything is an emergency. Nothing is that important. Just lie down. – Natalie Goldberg.