Digestion begins in the brain

I used to tell people that digestion starts in the mouth but it is actually way down the chain of events that result ineffective absorption and utilisation of nutrients.

Though I can generally tolerate most foods and don’t get an upset stomach from what I eat, I always feel emotion in my gut — be it excitement, joy, stress, sadness, it can hit pretty hard. And it totally makes sense that the tension in my head results in tension in muscles, which includes the gastrointestinal (GI) tract running from your mouth to your bowel.

For those who haven’t heard of the gut-brain axis, there is a general acceptance that how we think and feel has a direct impact on our ability to digest and absorb the food we eat (and vice versa).

These links have always been there and research is showing that a stressful environment can switch on or off genes (responsible for encoding our cells, which then determines everything about us, our health being one obvious factor) even before we are born.

This doesn’t seal our fate, but highlights how important our exposure to chronic stress is in determining overall health and wellbeing, some of which we have no real control over.

How stress impacts your digestion

Dyspepsia is the term used to describe a group of symptoms that result in a disruption to normal digestion. These can range from abdominal pain or bloating, through to cramping, gas, feeling uncomfortably full, nausea, loss of appetite, heartburn and reflux. For some, it can be something they struggle with daily.

The cause of dyspepsia can be neural (nerves run right through the entire length of your digestive system) or muscular (due to muscles around the organs of your digestive tract). The neural system sends and receives messages from nerves in your spinal cord and your brain and therefore what we think and feel can directly affect the tissues in the GI tract and their ability to relax and contract.

It is very hard to experience stress and feel relaxed at the same time and my osteopath can tell immediately, through the responsiveness of my muscles and ligaments to relax, that am stressed. I know athletes who have digestive problems that have lessened considerably since they have worked on releasing muscle tension around their pelvic region, highlighting how both physical and emotional tension can play a role in your digestive system.

Bitter greens are thought to be good for digestion. See point 9, below. Try this kale and avocado salad with grapefruit, fennel and walnuts.

There are things we can do

Some of the issues around digestion are to do with more than just a particular stressful situation, and if you are someone who has experienced long-term digestive problems, I suggest seeing a nutritionist or dietitian to help you get to the bottom of it.

Regardless of that, and if this is just a transient deviation from “business as usual”, some of these tips may help.

1. Remember that it is just a blip. Relax and allow your body to respond to the stress you're experiencing, especially if this is a physical manifestation of emotional turmoil. Like any situation, more stress about the problem will not help the original problem. Breathe deep (in through the nose, out through the mouth) to disengage your sympathetic "fight and flight" response and engage your parasympathetic "rest and digest" response. Relax.

2. Eat in a calm setting, undistracted, so you're able to focus on chewing properly (at least 15 times!) before swallowing your mouthful. THEN raise the next forkful. How often do you put your utensils to your mouth before finishing that first mouthful?

3. It is not proven, but I have had success with massage. There are some good guides on You Tube, or you can talk to your physical therapist about it, focusing on circular motions on the abdomen.

4. Yoga is thought to help with digestive issues, and I've seen (not tried) many yoga sequences said to promote a smoother digestive flow.

5. Ayurvedic medicine promotes a warm drink of water to increase peristalsis and when you add some lemon, this is thought to help flush toxins. I have not found scientific studies that support this practice, but who am I to argue with thousands of years of traditional Eastern wisdom? At any rate, it's a good way to bump up your water intake and many people need that. Start the day with one.

6. Once again I have not found a scientific study that supports this, but raw apple cider vinegar (you can make your own using Wendyl Nissen's nana-retro recipe) is thought to stimulate stomach acid production to help digestion. It does have some great benefits anyway, including some very cool effects on insulin sensitivity and reducing blood sugar response to a meal — so this is a pretty good habit to get into. Have a small amount in water before a meal (around a tablespoon) or include in your meal by way of a salad dressing.
   
   
7. Aloe vera juice has been found to be a safe, effective treatment for people with constipation-dominant irritable bowel syndrome (IBS).

8. Bitters have long been used in traditional medicine to help aid digestion by stimulating the action of stomach acid. A recent study suggests this is to do with increasing the blood flow to the stomach after eating, thus allowing the digestive process to take place. An up-to-date review of herbs used suggested that caffeine, in an encapsulated form, and gentian and wormwood, in liquid forms containing around 1000mg, were safe and effective for relieving digestive issues.

9. Bitter greens, such as kale and silverbeet, are thought to increase stomach acid production and help the liver produce bile. Bile is necessary for the digestion of fat in the diet which many people report experiencing issues with, particularly those who have recently increased their fat intake after years of following a relatively low fat diet, as enzymes that support fat digestion are down regulated. Try making kale chips or a kale and avocado salad with grapefruit, fennel and walnuts.
   
   
10. Don't drink water with your meals. I've researched in scientific databases again and again for studies to support the Ayurvedic notion that water will dilute your stomach acid production, thus impacting on your ability to digest and absorb food. I've not come up with anything. (Let me know if you have!) At any rate, if you're not comfortable with the reliance on traditional wisdom, then maybe link it to behaviour instead. Drinking with meals can encourage us to wash down our food, and we may do this if we tend to eat quickly and not chew our food properly.

Mikki Willidenis a registered nutritionist and lecturer at AUT University, where she lectures in public health nutrition and sports nutrition at the School of Sport and Recreation. ReadBite articles from Mikki or visit mikkiwilliden.com for more.