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If you’ve ever felt so stressed you couldn’t think, you’re not alone. Stress is causing many of us to struggle with decision-making, memory and accuracy in our day-to-day activities.

The problem is worse when we’re exposed to high levels of stress on a regular basis because this leads to chronically elevated levels of the stress hormone cortisol triggering long term changes in brain structure and function. The pre-frontal cortex the part of the brain used for executive functions is especially susceptible to the damaging effects of toxic levels of cortisol. The hippocampus, the part of the brain associated with learning, memory and emotional regulation has been shown to shrink during periods of high stress.

Cortisol is produced by the adrenal glands and has a number of very important functions in the body including regulating blood pressure, blood glucose levels (where it works in conjunction with Insulin) and keeps inflammation under control.

Which is all well and good except when it’s not.

While a little stress can be useful to upregulate performance, your Goldilocks brain doesn’t function well at either extreme of too little or too much.

If you’re someone who normally flourishes under pressure that’s fine so long as you are still taking sufficient time out for rest and recovery.

Because just as every professional athlete knows, to stay at the top of your game means putting in enough practice, working hard and resting in between.

Signs your stress levels are getting to be a problem typically show up first as forgetfulness and irritability. If you’ve misplaced your car keys for the fifth time this week or snapped at your colleague when they clearly didn’t deserve it, it’s time to take a step back to ponder – is my stress getting the better of me?

The dark side of neuroplasticity.

Other long-term brain changes associated with excessive cortisol and stress include an enlargement of the amygdala the part of the brain’s limbic system associated with emotional regulation. This is neuroplasticity at work, but not in a helpful way.

In this situation the brain remains switched on to a permanent state of high-alert. The limbic system seeks to take control of the governing body (the PFC) resulting in an emotional coup where you’re left running on adrenaline with an associated loss of emotional control and loss of access to logic, analysis or reasoning.

That’s why when under pressure even the smartest people can make really dumb decisions.

But the changes don’t stop there. The extra steak knives on offer when cortisol is running riot is the reduction in neurogenesis – the production of new neurons due to a loss of BDNF (brain derived neurotrophic factor) and an over production of specialised glial cells that produce myelin.

“Honey I shrunk my brain with stress” is unfortunately a potential reality.

Stress is a kill-joy. 

Too much cortisol dampens down your feel-good hormones dopamine and serotonin by damaging their receptor sites in the brain.

Dopamine plays an important role in our reward circuitry and motivation. If dopamine levels are low, it makes it harder to feel inclined to put in the effort on that joint project you’ve been working on and the associated lethargy may have you reaching for an extra coffee of three to try and restore a little mental energy.

The damage starts before you notice.

New research has shown how memory loss and brain shrinkage in middle-aged people is detectable before the symptoms show.

In this study, over 2231 people with an average age of 49 who were free of dementia underwent psychological testing and assessments for memory and cognition that was then repeated some eight years later. In addition they had fasting morning cortisol levels taken and an MRI scan to measure brain volume.

The bad news?

After adjusting for age, sex, smoking and BMI, high levels of cortisol were linked to poorer memory skills, cognition and lower total brain volume.

It can also promote weight gain – but that’s another story.

The other bad news?

Prolonged exposure to high levels of stress and anxiety increase your relative risk for depression and Alzheimer’s. Oh dear.

Which means there’s no time like the present to ensure your stress levels are kept in the healthy range.

There are some simple strategies shown by the research to help.

  1. Go for a walk, run or other form of aerobic exercise on a daily basis. This is a great way to lower cortisol while boosting dopamine and BDNF. Don’t just take my word for it – get your trainers on and discover the benefits for yourself.
  2. There are many different forms of meditation you could try and it is a practice so choose one and put it to the test. Mindfulness and loving-kindness meditation have been shown to be especially helpful. Even five minutes of meditation has been shown to produce cognitive benefits. More is better. Why not sign up to a class and make it a regular habit?
  3. Choose healthy foods. Stress can often lead to comfort eating where the preference for those foods high in salt, sugar and fat contribute to a lower mood and poorer thinking.
  4. Take time out to do other things than work. All work and no play is not only boring, it makes you less interesting too. It’s time to step out and explore other things. Why not take a dance class, sign up to study a subject you know nothing about or learn a musical instrument?
  5. Hang out with family and friends. Being social is a super power that reduces stress and creates that wonderful sense of safety and belonging.
  6. Share a laugh. Having a really good belly laugh is a fantastic physical workout and a brilliant way to dissolve away stress. Watch a funny video, visit your local comedy den or share a joke.

If high-performance is your game don’t let stress get the better of you. Choose to undertake a variety of stress detoxing techniques regularly and keep your mind ready for smarter, sharper thinking.

Dr Jenny Brockis

Dr Jenny Brockis is a medical practitioner and internationally board-certified lifestyle medicine physician, workplace health and wellbeing consultant, podcaster, keynote speaker and best-selling author. Her new book 'Thriving Mind: How to Cultivate a Good Life' (Wiley) is available online and at all good bookstores.

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