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Why the stress research doesn't add up (part 2/3)

After a period of stress we get ill – everybody knows that

It’s written in countless magazines and newspaper articles, so surely it must be true. Everybody can recall a time when they became ill after experiencing stress. The human mind is brilliant at seeing patterns, or so it likes to think. Apparently we're notoriously bad at it, often seeing what we want or expect to see.

A quick test

For example, which do you think is responsible for more deaths, shark attacks or falling aeroplane parts? It’s actually the latter, but falling aeroplane parts are far less interesting to the news media than shark attacks. When shark attacks do happen it’s all over the news, leading us to think they happen frequently. It’s called the ‘availability bias’.

There are 4 clear stages in the stress-disease chain:

  1. An individual is exposed to stress

  2. This stress causes their ‘stress-response’ to switch on

  3. The duration and magnitude of the stress response was big enough to suppress their immune system function

  4. This immune system suppression increased the likelihood of them contracting an infectious disease, and impairs their ability to fight it

A holey theory

Each of the 4 stages of this causal stress-disease chain have potential flaws in them, and in this article, I’m going to highlight some of them, then leave you to make up your mind about how watertight it is as a chain for explaining how somebody gets sick as a result of stress.

Hole in step 1 (‘An individual is exposed to stress’)

Stress is such an all-encompassing umbrella term, which has been applied to things as vastly different as electric shocks and starvation to traffic jams and being in the queue at Tesco’s.

What one person finds stressful another might be okay with. Take bungee jumping for example. You might be okay with that, whereas I’d rather not if you don’t mind.

When we’re talking about stress causing things, we need to start by clearly defining what we mean by stress, otherwise we’re just clumping together loads of things we don’t like as if they’re the same thing, when clearly, they’re not. Anger is not the same as anxiety, fear is not the same as overwhelm…

So, the first step in this causal chain needs a clear definition of it terms, otherwise its highly unscientific. How can you measure the impact of something you haven’t defined, or specified what it is?

Hole in step 2 – (‘This stress causes their stress response to switch on’)

Before I get into this one, I’d just like to point out the fact that stress here seems to be both a cause and an effect. So essentially it causes itself?

If you’ve seen the videos on stress, you’ll have seen the cartoons depicting pupils dilating, muscles tensing, breathing rate increasing, heart rate increasing, energy diverting from the digestive system, and so on…

But does this really happen every time we say we’re stressed? This can be tested quite easily, the next time you’re stressed check your pulse rate, your pupils in the mirror, heart rate and so on. Have they all changed?

This fight or flight mechanism is also switched on when we’re excited, exercising and even when we have an orgasm. Surely, they can’t all be bad for us, and lead to disease if we constantly experience them (although hopefully not the orgasms at work)

So, whilst I’m sure this response turns on in response to extreme situations such as torture (like in the animal studies), the jury is out on whether it switches on in response to everyday stress.

Hole in step 3 - (‘The duration and magnitude of the stress response was big enough to suppress their immune system function’)

Even Professor Robert Sapolsky, Stanford Professor of Biology, and author of the bestselling ‘Why don’t zebras get ulcers’ says in response to the idea that a change in immune profile automatically leads to disease, that “the odd thing is that immunologists are unsure about this”.

Professor Sapolsky also adds that “stressors, even if massive, repetitive or chronic in nature do not automatically lead to illness”. That’s an interesting statement, as many people believe it does. How many people in your organisation do you think believe that?

Hole in step 4 – (‘This immune system suppression increases the likelihood of them contracting an infectious disease, and impairs their ability to fight it’)

It’s easy to think that when we’re ‘stressed’ we’re essentially walking around without an immune system, and that any bugs floating around can dive on us and make us ill. Just like we see in adverts for household cleaning products. Those terrifying little blighters on our kitchen tops.

Plausible as this sounds, it doesn’t necessarily follow. Professor Sapolsky himself says that “few immunologists would be likely to assert that for every decrease in some measure of immune function, there is a tiny decrease in disease risk”.

So what does all this mean?

To help me out I’ll once again call on the words of Professor Sapolsky, considered to be the world’s leading expert on stress, saying that, “although evidence is emerging that stress-induced immunosuppression can indeed increase the risk and severity of some diseases, the connection is probably relatively weak, and its importance often exaggerated”.

Things aren’t always as they seem

Just like once we decide we want a new Peugeot and start seeing them everywhere, we conclude there are more out there, it’s purely a matter of us making ourselves deliberately aware of something we might previously have ignored. In the same way that connecting being ill with a period of stress is us choosing to see a causal pattern where merely correlation exists.

Bringing it home

So, what sort of message do you spread around stress in your organisation?

Is there an element of fear around making your employees ill by exposing them to ‘stress’, or do you opt for a more positive view of pressure?

How we talk about these things has a huge impact on how people experience them, so if we set people’s expectations that stress will make them ill, due to the nocebo effect we could actually be increasing that likelihood.

A final word from the guvnor

To close I’ll leave you with some final words on stress and illness form Professor Robert Sapolsky, who sounds like he’s sitting on the fence a bit here, when he says... “it is never really the case that stress makes you sick, or even increases your risk of being sick. Stress increases your risk of getting diseases that make you sick, or if you have a disease, stress increases the risk of your defences being overwhelmed by the disease”.

On that note, I'll leave you to make your mind up...


Jonathan Pittam

Mental Health Educator


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