‘We have a fish’s stress system’

To remove one of many people’s biggest fears: your pounding heart won’t conk out on you. “Heart failure is never caused by stress alone,” says Diederik Gommers. “There’s a reason why we almost never see heart attacks among young people – even though they are just as likely to be subject to stress as older people.”

Professor of Intensive Care Gommers is a frequently-consulted specialist on this subject. For example, he recently offered his expert opinion in the controversial Mitch Henriquez case, concerning a detainee who died after the police subjected him to a heavy-handed neck hold. According to some, Henriquez succumbed to ‘acute stress syndrome’; his stress levels were supposedly so high that his heart gave out. Nonsense, according to Gommers: “There’s no such thing as acute stress syndrome in the medical literature.” Together with two other professors, he was able to bring this point home to the Netherlands Public Prosecution Service, which promptly adjusted its sentencing demand.

If someone dies as a result of acute stress, it usually points to a different issue, explains Gommers. Cocaine abuse, for example, which can lead to dangerously high blood pressure. “But more often, the individual in question already has weak blood vessels, due to chronic high blood pressure, for instance, or smoking, or an aneurysm [a dangerously expanded blood vessel, eds.], which ruptures at that point.”

Short-term stress – like the kind you experience during an examination – is actually often very effective, according to Professor of Psychiatry Witte Hoogendijk. “It’s the well-known ‘fight or flight’ response. A tiny area in your brainstem – the locus coeruleus – starts producing noradrenaline, which helps you become more alert and focussed.”

At the same time, your autonomic nervous system (the part of your nervous system you cannot consciously control) sends a signal to your adrenal glands to boost the amount of adrenalin in your bloodstream. This steps up your heart rate, meaning more blood is pumped to your muscles and brain. The adrenal cortex also produces cortisol, which increases blood sugar: a source of extra energy for your muscles and brain.

All very useful in evolutionary terms. Stress increases your supply of oxygen and energy, allowing you to think faster and smarter and respond more effectively to danger. Hoogendijk: “At least it prevents you from getting run over by a tram.”

When you’re discussing the consequences of stress, it’s important to distinguish between short-term and chronic stress, Hoogendijk explains. Because chronic stress can be damaging, emphasises the professor, and he is coming across more and more examples.

This increase may be caused in part by our current society, suggests Hoogendijk. In the old days, stress naturally subsided when the concrete factor that caused it (a predator, for example) was gone. “Nowadays, stressors are mainly in our own mind, and it sometimes takes a long time to ‘clear them out’. Particularly when people start worrying – about abstract things like a reorganisation, for example. These matters are so abstract that you can’t really take concrete actions to resolve them.”

The result? Long-term, inescapable stress, which could contribute to a burnout or depression. Hoogendijk offers a few symptoms: “People have limited interest in their environment and other people, develop sleep disorders, they’re constantly tired and listless.” In evolutionary terms, these symptoms actually make sense, he explains. “Chronic stress signals to the body that it is under pressure. The body responds by ‘depressing’ itself, to save energy – for better days.”

While the mental aspects of chronic stress are unpleasant to say the least, the physical consequences are no picnic either. “We can observe shrinking neurons in lab animals that have been administered a large dose of stress hormones. In addition, these neurons form fewer synapses and connections with other nerve cells. While we still have little clinical evidence showing that this also occurs in humans, this would be consistent with symptoms like concentration issues.”

Moreover, long-term periods of elevated adrenaline levels in the bloodstream can contribute to high blood pressure. This in turn could damage arteries. The result: increased risk of cardiovascular diseases and decreased immunity to acute stress  –effectively rounding the circle.

Chronic stress can also lead to weight gain, with the ‘stress hormone’ cortisol playing a crucial role in this context. Professor Liesbeth van Rossum, internist-endocrinologist and member of the Young Academy of the Royal Netherlands Academy of Arts and Sciences, sheds light on the process.

The term ‘stress hormone’ is somewhat misleading in her view. “Among other things, cortisol regulates our immune system and blood sugar levels, as well as how our body metabolises fat,” she explains over the phone. “Nearly all our cells have receptors for this hormone. It’s literally of life-or-death importance – if your body no longer made cortisol, you’d actually die!”

But the more cortisol enters our bloodstream, as is the case with stress, the more our abdominal fat cells are encouraged to retain fat, Van Rossum continues. “In the case of chronic stress, you see cortisol values that are far higher than normal, for a longer time. Your brain responds by stimulating your desire for high-caloric food: you get ‘snack attacks’.” And this can lead to weight gain, mainly in the form of belly fat.

How soon things go south varies from one person to the next, Van Rossum is quick to add. Nearly half the population have a specific gene that makes the body extra susceptible to cortisol, but there’s also a small subgroup (‘5 to 10 percent’) that is affected to a far lesser degree. The latter group is lucky – they remain relatively protected against the negative physical consequences of chronic stress.

Fortunately, we can do something about our immunity to stress, the endocrinologist reassures us. In fact, it’s easier than you may suspect. “Rest and regularity – yes, it couldn’t be more boring,” she says jokingly. “A healthy lifestyle and a good night’s sleep are particularly important. Your cortisol level drops while you sleep. But when you don’t get enough sleep – shorter than six hours – this leads to more cortisol being produced. Which means your body goes into stress mode again.”

Psychiatrist Hoogendijk concurs. “Live like an animal,” is his advice, echoing the title of his book about stress. “But think like a human being! Short-term stress is fine, and you can use it to step up your performance. But if you’re sensitive to stress stay away from the rat race with its chronic stressors.” In evolutionary terms, that lifestyle doesn’t suit many people. Or, as he writes in his book: “We have a fish’s stress system.”