Tag Archives: fight or flight

The Effect Of Chronic Stress On Digestion

What happens when you feel stressed out about something? Your sympathetic nervous system, aka the “flight or fight” response, is activated.  That means your heart rate goes up, your breathing gets heavier, adrenaline starts pumping through your bloodstream and your body diverts resources away from your digestive system while sending more resources to your brain, heart and muscles.  

Because if you’re under attack, immediate survival trumps digestion.  You need to be able to think clearly, act quickly, and either run or fight. 

But you are likely to never actually be threatened by a predator.  Because humans no longer live among wild animals. Unfortunately, your nervous system didn’t get the memo.  It still functions the same way it did back when humans were rubbing sticks together to create fire.  

We rarely face physical threats in our daily lives (at least not in first-world countries).  Nowadays we deal with more mental and emotional “threats”.  But to our nervous system, they’re both the same.  

While increased adrenaline may help us run away from an attacker, it doesn’t do much to help us with more likely stress-inducing scenarios.  Like being stuck in traffic.  Or writing a test.  Or trying to meet the next deadline at work.  Or tolerating the 10th meltdown of the day from your toddler.  You cannot run away from these “threats” nor can you punch them in the face. 

 The flight or fight response was meant to enhance our performance to deal with short term physical threats, not prolonged emotional stressors.  This is why chronic stress makes us burn out.  When your digestive system is getting short-changed constantly due to stress, it cannot do its job properly.  It cannot extract and absorb the all the nutrients your body needs to function optimally.

Which eventually leads to much bigger health problems.   You could eat the healthiest diet in the world, but if you’re too stressed out to digest it properly, it won’t keep you healthy. 

Prolonged stress can cause gastrointestinal discomfort as well as increased intestinal permeability (leaky gut syndrome)1.  So not only does chronic stress make it difficult for you to get all the nutrients from your food, it also causes your gut to absorb unwanted molecules that it would normally block from entering your bloodstream. 

So what can you do to help your digestion when you’re feeling stressed?  

1. Breathe.  Make a conscious effort to breathe slowly to calm your nerves and activate your parasympathetic nervous system which counteracts your sympathetic nervous system.  It helps you calm down and sends blood back to your digestive system so that it can function efficiently.  Do some breathing exercises just before eating, as well as afterwards. 

2.  Practice “mindful eating”.  Focus on chewing your food thoroughly, and take time to relax after eating.  Your body needs time to digest the food you just ate.  If you regularly eat on the go, scarf down your food, and take little to no time to relax after meals, then you are not getting the most out of your food.  This is definitely challenging in today’s society where 30 min lunch breaks are the norm.  But it can be done if you carefully plan out your day.  If you don’t have time to sit and relax after you eat, try to schedule the least stressful tasks on your to-do list for just after mealtimes.   Consume your biggest meal of the day when you have plenty of time to not only eat but also have some down time afterwards to allow for optimum digestion. If you are hungry and have no choice but to eat on the go, eat a small snack to tide you over and save full meals for when you have more time.  

2.  Don’t eat when you’re angry.  And don’t eat with people who tick you off.  Anger triggers your sympathetic nervous system the same way fear does.  Either eat by yourself or eat with people who make you happy. 

3.  Listen to relaxing music while you eat.  This has been proven to activate your parasympathetic nervous system1.


1. LABBÉ, E; et al. Coping with Stress: The Effectiveness of Different Types of Music. Applied Psychophysiology. Biofeedback. 32, 3/4, 163-168, Dec. 2007. ISSN: 10900586.

2. LI, X; et al. Combat-training increases intestinal permeability, immune activation and gastrointestinal symptoms in soldiers. Alimentary Pharmacology & Therapeutics. 37, 8, 799-809, Apr. 15, 2013. ISSN: 02692813.