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Monday’s medical myth: stress causes cancer

Cancer is a disease of the body’s cells that affects around half of all Australians by the age of 85. Normally cells grow and multiply in a controlled way. But if something causes a mistake to occur in…

Stress can be nature’s way of dealing with adverse events. Sara Nel

Cancer is a disease of the body’s cells that affects around half of all Australians by the age of 85. Normally cells grow and multiply in a controlled way. But if something causes a mistake to occur in the cells' genetic blueprints, this control can be lost.

There are a number of chemical, physical and biological agents that have been shown to trigger the mistakes in the cell blueprint that cause cancer – but stress isn’t one of them.

We all encounter short- and long-term stresses in our lives, such as work challenges, relationship problems and illness, which have varying degrees of psychological impact. Stress can be nature’s way to help energise us to deal with these adverse events.

But high levels of stress can lead to anxiety and depression. These are serious, often interconnected, mental health problems that can affect your ability to work, maintain relationships and lead a fulfilled life. But three decades of study have found no direct association between stress and cancer, not even when stress is high enough to cause an anxiety disorder or depression.

So if you want to reduce your risk of cancer, the most important thing you can do is avoid or reduce the known risk factors – such as smoking, being overweight, having a poor diet, being physically inactive, exposing yourself to UV radiation and consuming excessive amounts of alcohol. Avoiding these risk factors is known as adopting a “cancer-smart” lifestyle.

Someone who feels stressed but lives a cancer-smart lifestyle is at no higher risk of cancer than a relaxed person with an equally healthy lifestyle. By the same token, a person who doesn’t feel stressed but smokes or does other things that are known to cause cancer is at higher risk than even the most anxious individual who has a cancer-smart lifestyle.

It may increase your risk of depression and anxiety but stress doesn’t cause cancer. Anna Gutermuth

So, in the absence of evidence, why do so many people think stress causes cancer?

One reason could be that people who are stressed tend to smoke, drink excessively, be inactive and have poor diets. But this does not make stress itself a cancer risk factor. (Ironically, tobacco use, physical inactivity, excessive drinking and consumption of “comfort foods” can actually increase, rather than alleviate, stress levels.)

Another reason for the myth might be the relationship between stress and the body’s immune system. There is some evidence that stress can lower immunity – the body’s natural defence against disease. Reduced immunity makes us more susceptible to some virus-related cancers, such as certain forms of lymphoma and Kaposi’s sarcoma. However, evidence of causation is limited and, again, complicated by the direct impact of behavioural risk factors on the immune system.

Studies also show that people who are emotionally distressed are more likely to think they are sick. The flip side is that dealing with serious illnesses like cancer can be stressful. But again, neither equates to stress being a cause of cancer.

The idea that a positive outlook will affect your chances of remission from cancer or your survival is another myth, based on stories we hear about people who “beat” their cancer through their “fighting spirit” or “determination”. There is no conclusive evidence that people who are distressed by their cancer experience have poorer clinical outcomes than those who feel “positive” – provided they follow evidence-based advice on treatment and care.

The perception that some patients did not survive because they were not as positive as others is unfounded and unfair. Dealing with a cancer diagnosis is tough enough; being pressured into thinking that the only way through it is to remain positive and thus minimise your stress can add to a patient’s individual burden.

Stress is, nonetheless, a significant health issue. If it’s a problem for you, you can learn calming techniques to help deal with it. Speak to your doctor or contact referral services such as Beyond Blue or Lifeline, which provide information and support to people with depression and anxiety. Improving your health and fitness by being more active and avoiding substances like alcohol and tobacco can also assist. And a healthier lifestyle will reduce your risk of cancer.

Fortunately, there’s no evidence that stress causes cancer – so it’s one less thing we need to worry about.

Join the conversation

23 Comments sorted by

  1. Bruce Moon



    I suggest you are splitting hairs.

    What you say is scientifically appropriate - there is no evidence that stress ON ITS OWN causes cancer.

    But, your quest to be scientifically correct also misleads.

    My understanding is that where a person has been exposed to a carcinogen, two other factors appear necessary in the development of cancer. These are a genetic disposition to tumour development (and not all people have this disposition), and a stressor.

    So, the process is:

    1/. exposure to a carcinogen in sufficient quantities (for the target person) to engender a cellular mutation, AND

    2/. a genetic disposition that enables tumour development, AND

    3/. a personal/lifestyle stressor that enables a weakening of the persons' defence system.

    The stressor is said to typically be an outlier event, not one that is adapted into one's lifestyle.


    1. Grendelus Malleolus

      Senior Nerd

      In reply to Bruce Moon

      Bruce - I am fairly sure that a "stressor" in the context of a very different thing to a stressor when talking about "feeling stress". I think it more likely that when discussing cancer we would be looking for a genetic, biological or chemical stressor that is causing some form of physiological stress that weakens the immune system to the point where a cancer can form. Defining it as a "personal/lifestyle stressor" is probably innacurate - which I think is the point of the article. Feeling stressed and having an stressed immune system are not the same thing.

    2. Bruce Moon


      In reply to Grendelus Malleolus


      My understanding is that the 'stressor' is the 'thing' that causes stress.

      And, the term stress relates to how an entity (here a person) relates to some form of pressure.

      So, getting a severe bout of influenza, or diarrhoea, or being hospitalised, or getting married, or, or, or are all 'stressors' which can have a destabilising impact on one's body.

      Whether one feels stressed by these is another matter.

      I take the tenor and meaning of Ian's article to be 'stress' as perceived by a person. This may be an innate tiredness from being unable to cope with something. Or, it may be a reaction to too much activity (ie work, sport, etc.).

      My understanding is that if any of these 'stressors' exist at the same time as the body experiences a carcinogen AND... then anything one perceives &/or experiences something as stressful is sufficient.


  2. Russell Hamilton


    "But three decades of study have found no direct association between stress and cancer, not even when stress is high enough to cause an anxiety disorder or depression"

    Which doesn't mean that stress isn't associated with cancer. Imagine how much more will be known in 100 years time.

  3. David Leigh

    logged in via Facebook

    Stress, as a singular factor, is not a cause of cancer. It is however one of several factors that need to occur in order to reach the state called cancer.

    The body's cell walls become clogged with modern manufactured fats and oils, replacing the Omega 3 fatty acids that negatively charge the cells exterior. This in turn lowers both the frequency and the potential difference between the mitochondria and the wall, allowing bacteriological invasion.

    The cell becomes depleted of oxygen, due to…

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    1. Paul White

      Senior lecturer, Pharmaceutical Biology, Monash

      In reply to David Leigh

      David, that's a pretty strange story you're pedaling there. Mammalian cells don't have cell walls - perhaps you're thinking of plants? And the extracellular surface of cell membranes is already negatively charged due to heparin sulfate gags etc. "cell frequency" as a cause of cancer is just silly.
      The treatments you suggest have no evidence base or any kind of sensible justification. Stress may contribute to cancer; perhaps cancer research is just not able to pick that link out of the noise, as Russell suggests. But your pseudo-science helps no-one.

    2. David Leigh

      logged in via Facebook

      In reply to Paul White

      Paul, I can assure you I pedal nothing, all cells have walls, otherwise the pyruvate would spill and the cell would not stay together. I don't know of any plant that gets cancer but then I am not a botanist. Professor Johanna Budwig spent most of her life studying the affects of different fats on cell wall construction and came to the conclusion that our modern diet (artificially processed foods, with manufactured fats and oils) was the cause of most illness, at a cellular level. As a senior lecturer…

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  4. CH Soames


    There are a lot of people inordinately attached to this particular myth. The interesting thing is how fired up they get in defence of it. I believe the reason for this is multidimensional, with the psychological and the philosophical bolstering each other in a positive feedback loop, driven by a contentious premise and a personal need. The need is for a sense of agency, the feeling that one's mind, rather than the body, is the ruler of destiny. The premise is that there is free will and that the individual can change the course of events using this facility.
    So the individual, rather than being a helpless victim of cause and effect, becomes a magical transformer of bodily processes and ultimate controller of fate.
    Unfortunately the converse position is that the victim is to blame if things don't go well, as the writer points out here.
    Those with the need for a belief in mind over matter should read Susan Sontag's "Illness As Metaphor".

  5. Clifford Chapman

    Retired English Teacher

    Why is this issue always presented in this feeble and unintelligent way?

    Three things are obvious from the outset:

    1. If stress per se caused cancer, virtually everyone would have to contract it, and
    2. A cure for cancer would be based, like a snake-bite, for example, on knowing what causes it, therefore if there is no clear cure for cancer, then stress could well be a factor, and
    3. Stress emanates from the mind and is therefore unable to be measured in the same way that a body's physical…

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  6. Pera Lozac

    Heat management assistant

    Stress influences a particular endocrinological body response. That change of body chemistry can cause a change in cell functioning and therefore it could, potentially lead to promoting cell mutation and hence cancer. Myth is something that can be proven - a statement "stress cannot cause cancer" is therefore scientifically irresponsible. Lack of knowledge is a source of ignorance not a space where one searches for definitive answers to complex questions.

  7. Clifford Chapman

    Retired English Teacher

    I do not mean this disrespectfully but, really, where is the academic rigour this site mentions ?

    I am sorry but no points people raise are responded or replied to, let alone addressed.

    I wonder if the author even bothers reading them.

    When the issue is presented in this way, it almost comes across as a 'fait accompli'.

    This so-called 'myth' is a Straw Man argument, if it can even be called an argument, or in my thinking, this interesting Latin term, which I have only just heard of…

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  8. Alison Moore

    Senior Lecturer in Modern European History, University of Western Sydney

    This article makes some valuable distinctions about what psychological stress has been directly clinically shown to effect, and what it has not. It does not prove that "stress does not cause cancer" but rather that no one has yet established a direct causation in spite of a considerable body of research that might be expected to reveal such a causation if it existed. It also ackowledges some of the possible indirect circuits of causation between psychological stress, physiological stressors and immune…

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  9. Clifford Chapman

    Retired English Teacher

    I'd like to continue this debate, if debate it is, because I do not feel the issues this article raises and purports to address, are in any real and meaningful way examined here.

    A couple of months ago, we, that is, my wife and I, were at the funeral of someone we knew who had been quite a heavy smoker and who had died through contracting lung cancer. His tumour did not respond to treatment.

    He was a decent person, very quiet and softly spoken, and at his funeral, one of his friends in his…

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  10. Agatha Fedrizzi


    As a lay and aavid reader of research on cancer, the one thing I can say with certainty is that cancer is a condition caused by the interaction of many factors some genetic, some environmental and it is the result of many factors going wrong never just one single factor. The search to find the silver bullet is perhaps laudable but it's clearly misplaced: cancer is a complex response of the whole organism. Happily, much of the research centres on looking at the interactions between identified factors…

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    1. Clifford Chapman

      Retired English Teacher

      In reply to Agatha Fedrizzi

      Agatha, I do hope you both read this and don't mind me commenting on it - I should say, 'my' there, by the way, and not 'me'.

      Do you not think that the 'interaction of many factors', which I do agree with, is bascially because we do lack certainty as to its inherent and underlying cause(s)?

      I do take seriously your comments on stress but do see the advice you were given, however well meaning, too simplistic. It's much more deeply based in an individual, in my view, which is why I do not think…

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    2. Sue Ieraci

      Public hospital clinician

      In reply to Clifford Chapman

      Ian Olver appears to have a very active life, between clinical work, research and publishing. He has taken the time to write a useful article. The fact that he is not back here debating retired English teachers in his area of specialty hardly requires personal criticism, does it? Maybe he's just too busy doing his stuff.

    3. Grendelus Malleolus

      Senior Nerd

      In reply to Sue Ieraci

      Sue - I also think Clifford may have been in error about the title of Professor Olver's next piece. I fairly certain it was "Why Sausages Taste Better When Combined With Onions" rather than "Are Only Good For You".

      (it was in fact on bowel cancer screening and Clifford managed - yet again, to get all critical because Professor Olver has other things to do than respond to shenanigans).

    4. Clifford Chapman

      Retired English Teacher

      In reply to Sue Ieraci

      I wasn't aware that retired English teachers were worthy of less attention than Public hospital clinicians, much less Ian Olver. Guess that's what comes of being a professor in your book.

      Perhaps you might care to respond to the actual topics I raised in my responses to this article, rather than adopting the role of apologist?