This is second article in a two-part series looking at digestive health from a nutritional point of view. In part 1 we looked at plant-based foods for relief from tummy troubles. In this article we look at the digestive system itself.
The digestive system encompasses all the parts of our body that are involved in converting food into energy. A healthy digestive system gives us a really good chance at having optimum health and wellbeing.
Many people experience digestive problems – ranging from occasional stomach pains, chronic constipation, through to allergies causing pain and distress (like coeliac disease), or more serious medical conditions like ulcers, irritable bowel syndrome and inflammatory bowel disease. To understand why these digestive problems might occur, plus what we can do to maintain a healthy digestive system, we need to understand how the digestive system works.
The digestive system – how it works
Humans are made up of millions and millions of living cells. Every cell in our body needs energy to make it work. The main function of the digestive system is to release the energy stored in food and make it available for each cell, in the format it needs.
If you think about an apple, it contains lots of nutrients that the body can use, however it´s too big in its natural form. This is where the digestive system comes in. Below is a diagram and description of the digestive process, so that you can start to appreciate the intricacy of the system and the interrelationships within it.
The digestive process starts in the mouth with biting and chewing the apple, together with the production of saliva (a chemical process) to start breaking down the apple into smaller chunks. These smaller chunks of apple then pass through throat into the oesophagus (carried by peristalsis, a wave action) and into the stomach. Gastric juices in the stomach (which are produced by the lining of the stomach) continue to break down the apple into smaller and smaller pieces. These gastric juices include three chemicals: hydrochloric acid, Pepsin (an enzyme) and something called intrinsic factor (needed for vitamin B12 absorption). The job of the stomach is to break the food down so that the proteins are available (a chemical action). Only a few very small molecules are absorbed in the stomach, namely water, alcohol and caffeine. (Note, the chemical action in the stomach needs a highly acidic environment, so to protect our body – and particularly the stomach lining – the gastric membrane of the stomach is slightly alkaline).
From the stomach, the contents empty into the duodenum, two to six hours after eating (the speed depends on the food type). It then passes through into the small intestine, which is where the main chemical breakdown of food takes place and where most absorption of nutrients and water occurs (about 90% here). (The digestive juices in the small intestine are full of enzymes and are alkaline, to neutralise the stomach acid).
The final stage is that the now unrecognisable apple passes into the large intestine (or colon), which is where the final absorption of nutrients takes place. Our colon manufactures certain vitamins and this is where faeces are produced. The “apple” is moved by peristalsis (wave action) down through the colon. Any last water is absorbed here, which is why faeces start to become firm. The faeces are then expelled from the body, 1-2 times per day is normal.
There are also three key organs involved in the digestive process: the liver, gall bladder, and pancreas. It is important that these three organs also function optimally to ensure proper digestion.
All nutrients from the apple that we ate are absorbed into the blood stream and carried first to the liver. From there they go to every other part of the body. The liver produces bile, which is stored by the gall bladder. The liver also filters out any toxins introduced into the body in the food or drinks that we consume and passes them out through our urine. Too many toxins, like alcohol, caffeine, smoking or chemicals and preservatives in food, can start to overburden the liver. Following a healthy natural plant-based diet can deliver great nutrition to the body, giving the chance for the liver to have a lighter workload and restore proper functioning, detoxing and clearing out.
The gall bladder stores bile from the liver and releases it into the small intestine via the duodenum. Bile is released to break down fats, before the pancreatic juices further digest them. The pancreas secretes the hormones insulin and glucagon, needed for sugar regulation, as well as some digestive enzymes, needed for the final digestion of food.
What can interfere with digestive health?
As you can see from the above description, the digestive system is complicated and inter-dependant. Our body is amazing, so there are many feedback loops in the digestive system, to keep things balanced and working optimally. You can probably also see there are many points where something can interrupt our digestive system, leading to digestion and other health problems.
There are some lifestyle habits that can interfere with our digestive health. These include:
- Poor diet: too much over-reliance on processed food, eating too many foods with insufficient nutritional value, eating too many acidic foods (read more below).
- Drinking insufficient water
- Alcohol: too much will overburden the liver
- Allergies and intolerances (read more here)
- Stress: physical, mental and emotional
Within the digestive system, an imbalance can also create health problems. For example:
- A lack of intrinsic factor in the stomach can lead to vitamin B12 deficiency and something called pernicious anaemia, even if you are supplying sufficient B12 in your diet or taking supplements.
- Insufficient bile (and lecithin) for the small intestine can lead to the formation of gallstones.
- Insulin production failure by the pancreas, can lead to diabetes
- Hardening of the faeces in the bowel can lead to bowel impaction and to bowel inflammation
All is not lost! Read on.
How to improve your digestive system
There are some really easy things you can do immediately to improve your digestion, without spending lots of money on fancy supplements:
- Relax before eating. Eat in a quiet environment, take your time.
- Chew your food well. Eating quickly means the food is less broken down in the mouth, making it harder for the rest of the digestive process.
- Eat a healthy balanced diet – we suggest a plant-based diet is a good place to start, read more in our associated article: digestive health part 1: plant-based foods to provide relief from tummy troubles.
- The balance of acid-alkaline in the stomach is important for our digestive system. All foods that affect this balance can cause problems for our digestion. Try to avoid a highly acidic diet. Acidic foods include sugars, processed foods, meats, dairy and eggs.
- Consider what types of food you eat and when. Some foods take longer to digest than others. For example, fats take the longest time to empty from the stomach, whereas carbohydrate rich foods empty after a few hours. Fruits empty the fastest. Try to eat a low-fat meal just before going to bed.
- Drink sufficient water throughout the day. Too little water can contribute to your faeces becoming too hard, resulting in constipation or worse. However, you might want to consider not drinking water with your meal. Some nutritionists believe that drinking water with food could dilute the digestive enzymes, meaning food is less likely to breakdown and digestion (therefore absorption of nutrients) will be less. If you want some ideas on how to drink more water, read our article: water – how to maintain your hydration this summer.
- Consider how to enhance the healthy bacteria in your colon – eat natural yoghurt, or take probiotic supplements (make sure they can survive the highly-acidic stomach environment).
Take action: Keep a food and symptom diary
Buy a notebook. Be present in your body as you eat, and for a few hours after eating. For two weeks write down everything (yes, everything) that you eat and drink, as well as the time. Record how you feel and any symptoms that you experience – be specific. Note the time you experience the symptoms. Record your bowel movements (in detail!). After two weeks, take a look back through and notice if you see any patterns. If you want to look deeper, also record your emotional state at the time you eat and also the symptoms that you experience. You can then make more informed decisions about what to eat or avoid.
Do your research
If you regularly experience digestive problems, there is a load of information available on the internet. Do your research, speak to other people, try things out.
Seek professional help
If you regularly experience digestive problems then we recommend you seek help from a suitable health professional for a proper diagnosis. You could see your local doctor, work one-to-one with a nutritionist or find someone to test you for allergies. A nutritionist can also work with your food diary.
Try a plant-based diet for digestive health
Removing some of the items that cause your digestive system to work harder can contribute to an improved digestive system and better health. Read my linked article: plant-based food for digestive health which contains lots of tips on foods that can support you during times when you experience problems.