Most of us know stress is bad for us. But turning it off isn't always easy it's not just a simple switch you can turn on and off at will. What's more, stress isn't always bad for us in fact, some of you will be pleased to learn (if you didn't know it already) that we're actually designed to function with some level of stress. Importantly, there is good stress and bad stress, or positive and negative stress. If we're interested in being the best, most vital and healthy beings we possibly can be, we need to ensure we've got the right amount of positive stress, combined with as little negative stress as we can muster.
What kind of stress are you under?
Dr Hans Selye, the widely acknowledged 'father' of stress research, devoted an entire book to the subject of 'stress without distress' [source]. What's clear from more than half a century of research on the subject is that we all have different levels of stress tolerance. Some people are able to cope with much higher levels of negative stress than others, and one person's positive stress might be another person's negative stress.
Stress is a reaction caused by a stressor of some sort. It might be excessive hours of work, a series of seemingly unrealistic deadlines, or a tyrant of a boss. It could be exams or a bully at school, a poor diet, or an under-par immune system that's struggling to ward off infection. It might also be pushing yourself to the limit in a given sport or overdoing it in the gym. As Dr Selye said, "a painful blow or a passionate kiss can be equally stressful" - at different times, or to different people. He also reminded us that "complete freedom from stress is death".
The nature, duration, severity and, in particular, our response to stress, are what determine whether stress is ultimately going to do us good or harm. And don't forget, you can suffer negative stress that also does you good. An example of this is being caught in traffic on the way to the airport and then running late for a plane. The psychological and physiological stress response that causes you to run to the check-in juggling all your bags, and then through the terminal feeling as if you want to bowl over any slow-moving passengers or over-zealous security officers isn't good for you. Your nervous system is on red alert, your heart has nearly punched its way out of your chest, and your adrenals are spent. But, although severe, it's short-lived. Once you are seated in the aircraft, the relaxation that comes over you allows you to recover quickly. Ultimately it was your stress response that got you on the plane and, as unpleasant as it was, it might well have put you in a better and healthier position than facing the consequences of missing your flight. In evolutionary terms, you've successfully escaped a sabre-tooth tiger and that's why the 'flight-or-fight' response remains with us today.
The Stress Response
Psychologists have come to define the stress response as the biological and psychological response to a threat that we don't feel we have the resources to cope with adequately. That of course relates specifically to negative stress. Multiple systems in the body come into play, from the endocrine (hormonal) system, the nervous system, the immune system and the digestive system.
When confronted with a threat or potential stressor, the first thing we do is evaluate it with our senses. Our ability to do this very quickly helps us to survive as a species. If we decide the threat is real, and that we need to act quickly to reduce its impact, we trigger a cascade of events affecting multiple systems in our body, including three key endocrine organs - the hypothalamus and pituitary gland in our brain, and the adrenal glands that sit atop our kidneys. This is known as the 'HPA axis' and is a key part of what is sometimes called the psychoneuroimmunological (PNI) or - wait for it - psychoendoneuroimmunological system, owing to the multiple systems affected. More recent work suggests the gut and the gonads are also involved in the stress response; as a result, some functional medicine practitioners find themselves referring to the system as the HPAGG axis.
The key 'stress hormones' released from our adrenal glands belong to a group of steroid hormones called the glucocorticoids, the most important actor of which is cortisol which is synthesized from cholesterol. Cortisol and the HPA axis operate a complicated negative feedback system to control the stress response with hormones like adrenaline, and also to bring it quickly back into balance once the stress or threat has subsided.
What happens if you over-stress your body?
Typical stress responses include elevated heart rate, rapid breathing, elevated blood sugar levels (caused by cortisol triggering glucose production in the liver), decreased digestive activity, loss of appetite and a suppressed immune system. It's not hard to see how this system that was designed primarily to help us survive more severe and short-lived threats and stresses, starts to create havoc with our bodies in our modern world where chronic stress, even though less severe, is so common. If our bodies are not given the chance to get back to our unstressed balance point things often go awry.
Gaining weight, developing 'cortisol tyres' around the mid-section, suffering gastrointestinal problems or regular infections, a failing memory, and losing our capacity to tolerate 'normal' levels of stress, are all examples of symptoms of chronic, inadequately managed stress.
The good news is there's lots we can do to transform negative stress into something more positive, as well as supporting the body nutritionally so it can cope better with stress. And that's going to be the subject of the next three articles in this series.