ALLOSTASIS Nothing is constant but change.

— HERACLITUS —

he term allostasis was coined by a researcher called Bruce McEwen a couple of years ago. He defines it as ‘constancy through change’, which is a bit of an oxymoron. A lot of people have a hard time understanding the concept and I don’t blame them. Another way of explaining allostasis is that it is the process by which the body and brain are able to stay in a working balance by adapting to the things that are currently happening – whether that be waking up in the morning, getting hit by a baseball bat, giving a speech, exercising, getting thirsty, etc. When we make the transition between sleep to waking up our bodies are subjected to a lot of stress – for most people this is the most stressing activity that will take place during the entire day. To deal with the sudden change of waking up, our bodies are flooded with various hormones to help us make the transition. Change is stress, almost.

But that’s not all; then there’s also the mental imaging of things being experienced as well. For example when we imagine a future scenario – which we constantly do – it affects the body through allostasis. This constant communication between brain and body is commonly known as the brain-body connection. They both influence each other. A key insight from this scientific field that we keep hearing over and over again is that being constantly stressed is bad for us (no shit Sherlock!) and gives rise to several adverse effects that can be visibly observed in certain parts of the brain, such as in the hippocampus, which is associated with memory function. This is where it is crucial to make the distinction between consciously induced stress, such as when working out, and that of prolonged unconscious stress which happens by thinking or anticipating negative things and feeling bad. Even though our thoughts are merely anticipations of a non-physical future scenario, the brain experiences it as if it was happening right now (to a varying degree depending on the vividness of our

imagination). The brain then responds to the experience by telling the body what to do. Surely you have experienced almost falling asleep and feeling like you started falling or that you were about to trip, only to respond to the situation as if it was really happening and

T

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Why Zebras Don’t Get Ulcers

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instinctively react by sitting up in bed or kicking with your legs. You have likely also experienced thinking about fighting someone and felt your body surge with adrenaline and start to sweat. Much in the same way as explained in these examples; when you have negative anticipations and feel nervous or scared before some event your brain perceives it as happening now and produces the appropriate hormones in your body which then give rise to the corresponding emotional response of fear in you.

The key takeaway is that whenever you have thoughts that make you feel bad and induce negative emotions or make you feel stressed you are actually physically hurting yourself and slowly etching this thought into your brain little by little. After years of repeating

negative thoughts and mentally experiencing self-induced stress you not only experience negative emotions, but may adversely affect your health.

So what can you do about it?

What you can do about this is first to practice the skill of inducing a relaxation response in your body (calming down) as soon as possible after you have gone through some stressful situation, such as; after a tough workout, a scary situation, a serious accident, etc. The other thing that you can do about it is to think less about negative things and stop projecting yourself into the future, worry less. Another thing that works well for me is to randomly stop every once in a while and stand completely still until I become relaxed. It helps a lot when I remember to do it if I am stressed as I go about my day. But these things are as with the metacognition, it is not something that you develop overnight. Mindfulness – if you want to call it that – isn’t something you that you can pick up by going to a yoga class one time, stretch in some weird position, and come home doing perfectly. As with meditation, I dislike the term mindfulness because many people confuse it for weird new agey things.

Continual and prolonged periods of responding to stressors, whether physical or mental, will exhaust your body and give rise to what Bruce McEwen calls allostatic load, which is when allostasis is no longer helpfully adaptive to the brain and body, but actually becomes harmful as a result of continual wear and tear. The easy explanation is that you overexert yourself without being able to sleep or relax properly. That’s when you tend to get sick, hurt, or – if you have a lot of bad luck and happen to be a kid – may suffer serious consequences such as stress-dwarfism. This last example is likely what gave rise to the ‘myth’ saying that kids shouldn’t be lifting weights as it would stunt their growth.

It’s important to point out that increased stress does not absolutely equate to adverse effects such as becoming sick or getting hurt.

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Science does not have any one specific answer to why we become sick or unhealthy; it hinges on way too many different factors. There are people who can do a lot of unhealthy things throughout their lives and still remain completely healthy. Except for stress levels (sleep included), other important factors are: genes, personal attitude, and diet. The current popular scientific view of stress – which I agree with – is that unhealthy levels of stress increase the likelihood of various ailments through a number of ways, notably by decreasing the potency of your immune system.

Other negative side effects of stress and allostatic load include a less potent brain. We go into this a bit deeper later in the chapters of the prefrontal cortex (PFC) and the amygdala.

Specific areas of the brain that show several forms of plasticity, are involved in allostasis, are affected by allostatic

load, and are implicated in stress-related vulnerability to chronic health conditions include regions of the prefrontal

cortex, hippocampus, and amygdala. These brain areas represent the primary targets of preventative and intervention efforts to reduce the public health burden of

mental and physical illnesses. —BRUCE S. McEWEN & PETER J. GIANAROS —

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