The word "stress" doesn't figure in the successful entrepreneur's instruction manual. If you're going in, you go all in -- or you go home. 

But what if going all in means losing your memory or worse, shrinking your brain?  

Can stress shrink your brain?

A large study published last month looking at the brains of over two thousand healthy young to middle-aged men and women, found an association between having high circulating levels of the stress hormone cortisol and brain thinning.

Those with higher cortisol levels also had worse memory.  

This isn't the first study to link stress to brain "shrinkage."A 2017 study from Sweden found brain thinning associated with chronic work stress could be reversed by giving stressed workers a respite from work and cognitive therapy.

The Swedish study's authors concluded chronic stress wasn't just correlated with the thinning -- it was likely "causing" it.

Why has stress suddenly become so toxic?

One possible reason is lifestyles in the past used to include "stress buffers" that helped us recover from bouts of stress over the course of the day.

Many of these buffers have disappeared as our lifestyles have changed -- as a result there's a delay in how quickly we're able to shut down a stress reaction once it has begun. This means we spend more time being stressed than we used to. 

 Here are five examples:

1. The movement buffer

While high-intensity exercise raises cortisol, low-intensity, longer duration exercise seems to bring cortisol levels down.

Before the tech age and sedentary jobs, our days would include frequent, low-intensity movement. Today, many of us move very little during day and finish off the day with a session of high intensity exercise.

Although daily exercise is good for us, doing it this way flips the stress-relieving logic on its head. 

2. The darkness buffer

Melatonin, the hormone we release when it gets dark at night, can act as an anxiety-reliever. Our overnight dose of darkness used to be a natural nocturnal stress antidote before we started using blue-light-emitting screens late into our evenings: blue light and bright light hinder melatonin production.

3. The calm buffer

Instant communication has resulted in constant demands on our attention. These demands force us to stay vigilant so the brain can't relax after a stressful experience. Being on edge also makes us more prone to becoming stressed again.

4. The social buffer

Life in the digital age leaves little time for face-to-face relationships and yet humans have evolved as tribes and need social connection to feel safe and buffer stress.

5. The wrong kind of buffer

Although physical stress has largely disappeared from urban lives, we continue to rely on stress strategies that target physical stress when we're emotionally stressed. We're using the wrong kind of stress buffer.

How can you protect yourself from the effects of chronic stress?

Here are five strategies taken from my book Stress-Proof  that target these five lost stress buffers: 

1. Walk.

Move at every opportunity throughout the day -- not with the aim to get fit or lose weight, but to offload stress. Walk around for five minutes every hour. Walk a stop instead of using transport. Take calls while walking; have walking meetings.

2. Sleep in a cave.

Dim the lights and wear blue light-blocking glasses if you use a screen late in the evening.  Avoid large meals, loud noise, excitement, caffeine and intense exercise in the evening. Get more daylight during the day.

3. Grab (your own) attention.

Make sure you--not your environment--are controlling your attention. Delegate time for checking your phone, rather than allowing your phone to summon you. Schedule in periods of singular focus where you don't multi-task.  

4. Hang out with your tribe.

Aim to be part of some kind of tribe, whom you identify with, feel comfortable around, and check in with regularly. According to latest research, even a virtual social tribe might do.

5. Don't dwell.

Never relax immediately after an emotionally stressful experience -- do something intense! Distract yourself with something so absorbing your mind can't wander.

If your mind is empty, it will keep going over on what just happened, amplifying your emotional reaction.

If you can't find anything intense to distract yourself with, keep a selection of games like Tetris on your phone that you can access at any time. Keep playing until you forget what just happened.

Stress is as old as we are, but the coping mechanisms we've always relied on are rapidly disappearing from our changing world.

We now stay stressed for longer after experiencing the same things we used to quickly recover from. 

Incorporating lost "stress buffers" such as these back into your lifestyle will help you recover faster from stress, and may help ensure your hard-earned success isn't attained at the cost of a poorer memory -- or worse, a possibly thinner brain.