Anxiety and Digestive Health are Related: Here’s How to Optimize Your System

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Prepared by: Heather Lillico, R.H.N., R.Y.T.  |

Nobody likes feeling anxious, but anxiety does serve a purpose. It alerts you to danger and allows you to either fight back or run away. A little warranted anxiety keeps you alive, but when you’re living in a constant state of nervousness and fear, that’s when it becomes damaging to the body.

The anxiety monster, as I’ve lovingly dubbed him, causes two chemical releases from the adrenal glands. Immediately, epinephrine is released via a sympathetic neural signal. Then a few moments after that cortisol comes onto the scene.1 These reactions help you move and think fast, but in many cases of anxiety there’s no imminent survival threat. It’s more likely to be a stressful e-mail rolling in from your boss, a presentation that you don’t want to give at work, or an alert from social media telling you yet another high school friend just had a baby thereby reminding you how behind your life is. The issue is that at a physiological level your body can’t tell the difference between that and a real threat. 2

When anxious, all your body’s resources are shunted to help you survive, and you know what takes a back seat? Digestion! Anxiety and digestive health are inexorably linked. Your body can’t focus on absorbing nutrients when in danger as it’s in pure survival mode, utilizing the resources it already has.

In fight or flight mode, your parasympathetic nervous system, which needs to be activated for digestion, won’t switch on. Let’s talk about anxiety and digestive health and walk through the stages affected. Spoiler alert: it’s all of them!

Digestion begins in the mouth. Enzymes are released by salivary glands targeting carbohydrate digestion. 3 When anxious, chewing is reduced because you’re in survival mode. Chewing is the signal for stomach acid production. It’s like saying, “Hey stomach, get ready! Food is coming your way!” That parasympathetic activation is normally a signal for stomach acid production too, 4 but it’s absent when the anxiety monster is hanging around.

Without adequate stomach acid, food enters an environment that’s less acidic than normal and therefore harmful bacteria on food aren’t killed off. 5 Stomach acid has other functions such as activating protein digestion, and helping to absorb minerals like magnesium, zinc, and selenium. Many people are already at risk of deficiency in these minerals if they consume a diet high in processed food.

As food travels along the path to the small intestine, it now carries more bacteria and is less prepped for absorption. Bacteria on food is concerning as the beneficial bacteria in the small intestine only organize themselves in a thin layer and can be easily disrupted. When disturbed, the mucous lining degrades and food seeps out undigested leading to food sensitivities, 6 a very common issue I see among clients with anxiety.

Digestive organs are also impacted in response to anxiety. The pancreas releases fewer enzymes, bile production from the gall bladder is impaired, and the liver produces more inflammatory markers.

All the previous steps have set the body up for sub-optimal digestion before it heads to the last site of absorption, the large intestine. This is where water is absorbed, and good bacteria produce vitamins such as B Vitamins and Vitamin K. 7 These functions are negatively impacted when food enters undigested and with bad bacteria in tow.

Anxiety and digestive health are so intertwined that every stage of digestion is impacted when the anxiety monster strikes. Now what can you do about it? While a personalized assessment with a Holistic Nutrition Professional will give you more details, here are two key steps!

  1. Calm Your Nervous System

Switching yourself over to the parasympathetic side is one of the best things you can do for digestion (and for your mental health)! 8 I always recommend deep belly breaths before eating. Not only does this activate the rest and digest side of your nervous system, but it also leads to a more mindful eating experience, making you more likely to slow down and chew your food thoroughly. Remember, digestion begins in the mouth!

  1. Eat to Support Your Mental Health

This key step deserves an entirely separate article, but briefly, the bacteria in your gut can help reduce feelings of anxiety. 9 They have a role in GABA production, your body’s relaxing neurotransmitter. 10 These beneficial microbes can also reduce cortisol levels in the body. The best foods to eat to support your gut and therefore your mental health are probiotic and prebiotic foods. Fermented (or probiotic) foods such as sauerkraut, tempeh, kombucha, and cultured vegetables all contain beneficial bacteria to support your gut. Foods like garlic, onion, asparagus, dandelion greens, and Jerusalem artichokes all contain prebiotics which feed the bacteria in your gut. Why not try out a big salad bowl with a bunch of these ingredients paired together?

The advice I find myself giving over and over is to slow down, and eat a variety of real, whole foods. Both your anxiety and digestive health will thank you for it.

– Posted August 2019 –


  1. Harvard Health Publishing. Understanding the stress response. Updated May 1, 2018.
  2. Duval ER, Javanbakht A, Liberzon I. Neural circuits in anxiety and stress disorders: a focused review. Ther Clin Risk Manag. 2015. 11:115-126.
  3. Pandol SJ. The Exocrine Pancreas. San Rafael (CA): Morgan & Claypool Life Sciences, 2010.
  4. Dobrek L, Nowakowski M, Mazur M, Herman RM, Thor PJ. Disturbances of the parasympathetic branch of the autonomic nervous system in patients with gastroesophageal reflux disease (GERD) estimated by short-term heart rate variability recordings. J Physiol Pharmacol. 2004. 55(2):77-90.
  5. Tennant SM, Hartland EL, Phumoonna T, Lyras D, Rood JI, Robins-Browne RM, van Driel IR. Influence of gastric acid on susceptibility to infection with ingested bacterial pathogens. Infection and 2008. 639-645.
  6. Berin MC, Sampson HA. Mucosal immunology of food allergy. Curr Biol. 2013. 23(9): R389-R400).
  7. Azzouz LL, Sharma S. Physiology, Large Intestine. Treasure Island (FL): StatPearls Publishing, 2019.
  8. Rea P. Clinical Anatomy of the Cranial Nerves. Academic Press, 2014.
  9. Foster JA, McVey Neufeld K. Gut-brain axis: how the microbiome influences anxiety and depression. Trends in Neurosciences. 2013. 36(5):305-312.
  10. Strandwitz P, Kim KH,Terekhova D, Liu JK, Sharma A, Levering J, McDonald D, Dietrich D, Ramadhar TR, Lekbua A, Mroue N, Liston C, Stewart EJ, Dubin MJ, Zengler K, Knight R, Gilbert JA, Clardy J, Lewis K. GABA-modulating bacteria of the human gut microbiota. Nat Microbiol. 2019. 4(3):396-403.

Heather Lillico is a Toronto-based Holistic Nutritionist and Yoga Instructor that crushes anxiety with nourishing foods and mindfulness techniques. Visit her website

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