In this review, we look at considerations for those struggling with symptoms relating to impaired digestion and absorption.
Introduction to digestion
After you swallow your food, we rely upon a number of automatic responses by the body to help break that food down into something that can be absorbed through the stomach, small intestine and large intestine, directed predominantly to the liver first, for it to then be sent around the body where the cells in our body are able to utilise it for all bodily functions.
You are not just what you eat, you are what you eat, digest and absorb!
We rely upon a number of specific acids and enzymes to help us break these foods down. Yet the release of these acids and enzymes, as well as areas such as bowel motility, are influenced by a number of factors.
As you may already be aware, without optimal digestion and absorption you may struggle with symptoms such as gas, bloating, constipation, bad breath, feeling heavy after meals, reflux, changes in stool consistency and more.
Digestion starts in the brain
Even before food enters the mouth, we should be thinking about what we are about to eat. Smell can also play a crucial role along with thoughts in its stimulatory effect on digestive juices, saliva, enzymes, and digestive hormones in anticipation for the food we eat. Not only that, blood flow can also change to support digestion.
The trouble is many of us simply don’t respect this primal reaction to food and what is required for that primal reaction to take place efficiently.
Imagine for one second you were a zebra being chased by a lion. Do you think that while you are being chased your body is primed to eat and digest food. Of course not, your body is focused on survival. This means diverting blood flow away from the gut, lowering acids and enzymes that assist in digestion. Even just for a minute, think about the dry mouth you get when standing up to do a presentation. This is stress response in action causing your digestive system to shut down!
The trouble is that modern life makes us feel like we are zebras in a marathon race with a lion. Rather than experiencing acute stress we now have a number of chronic stressors. It’s no wonder that so many people have chronic digestive issues when we are often caught in a vortex of chronic stress.
Could something as simple as improving someone’s eating environment and habits be beneficial to how they digest food?
Never underestimate the role of stress, anxiety and our fast-paced 21st century lifestyle in our ability to digest and absorb foods.
Chew, Chew, Chew
Our mouth helps us to chew up and breakdown food into smaller pieces. With enough chewing it helps to liquidise our food, increasing the surface area making it easier to be broken down further down the digestive tract.
Enzymes present in our saliva, help to begin the digestion of carbohydrates before they are eventually deactivated by acids in the stomach that are primarily used to help breakdown protein.
Another enzyme found in the mouth is lipase and this is known to breakdown fat. Various forms of lipase act on fats throughout the digestive system including the mouth, stomach and small intestine.
If you have issues with digestion and absorption and you recognise that there could be improvements made with “how you eat”, please read my article The importance of mindful eating.
Next step, the stomach!
Once food hits the stomach, the stomach then acts like a blender where the food can be chopped, diced and liquified into smaller and smaller pieces while mixing with digestive juices until it is eventually a liquid known as chyme. The stomach is where the majority of protein digestion takes place with the action of hydrochloric acid (HCl).
Hydrochloric acid helps to not only break down proteins, but also helps in the sterilisation of foods as well. Often people with lower levels of HCl will often be more sensitive to food poisoning incidents.
Equally people with low HCl appear to be more prone to a loss of oral tolerance. Loss of oral tolerance is where one becomes steadily more sensitive to the foods that they eat, partially because of their inability to break food down. This is often why running food sensitivity testing is a futile act, other than providing a window of opportunity to lower immune responses while fixing other underlying causes.
Most food is absorbed further down the digestive tract, but absorption of alcohol, water and certain minerals does take place in the stomach.
Our stomach also produces intrinsic factor in the stomach, which is a type of protein. Intrinsic factor binds to vitamin B12 so it can be readily absorbed in the intestines. Often people with digestion issues, perhaps low stomach acid, will have low levels of intrinsic factor resulting in lower levels of vitamin B12.
As we age our production of HCl and intrinsic factor tends to decrease, resulting in an increased risk of nutrient insufficiencies, especially vitamin B12. Some of the main symptoms of low B12 are muscle weakness, general fatigue or anaemia, reduced cognitive function or low mood to name but a few.
Once the chyme leaves the stomach it enters the small intestine. This is where further digestion takes place, especially fats, due to the action of lipase and bile acids, and then also carbohydrates and proteins through other enzymes produced by the pancreas.
Time for absorption!
The small intestine is roughly 20 feet long and spread flat could cover the size of a tennis court. It is at this crucial point that digestion is completed and much of the absorption takes place.
The structure of the small intestine is crucial for the absorption of nutrients. By having a wave like structure with hundreds of finger-like protrusions and millions of more finger-like protrusions from them, this increases the surface area exponentially. These finger-like protrusions are known as villi and microvilli, all of which are one cell thick and allow for the absorption of nutrients whilst blocking the absorption of substances that are deemed foreign to the body.
Most of your nutrient absorption takes place in the 3 main sections of the small intestine. In the first part of the small intestine, the duodenum, it still should have a fairly acidic environment which helps with the absorption of many minerals. Certain water-soluble vitamins such as many of the B vitamins and vitamin C and fat-soluble vitamins, such as A, D, & E. Thus poor HCl in the stomach can still have negative effects on the absorption of nutrients further down the chain.
A large majority of your fat is absorbed in this section of the small intestine along with some carbohydrate absorption as well. This section and the overall digestion and absorption process are heavily reliant upon the pancreas and liver/gall bladder functioning optimally. This is because the pancreas releases enzymes that help to break our food down and the gallbladder bile acids to help emulsify fats.
Proteins and carbohydrate digestion and absorption continue in the jejunum, and then in the final phase in the ileum it finishes the job of digesting many nutrients including B12 and dietary cholesterol. The colon then completes the job by absorbing water, salt, vitamin K, short chain fatty acids and potassium.
8 ways boost digestion & absorption
De-stress. If stress plays a major role in your life, then look at ways in which you can help to manage stress or reframe stressors, so they have less of an impact on you.
Practice mindful eating and chew thoroughly. As the Indian proverb states, drink your food and chew your water. This means chew until your food is liquified before swallowing and instead of gulping drinks down swish it round and take your time.
Eat bitter foods with a meal. Bitter foods can help to stimulate digestive juices naturally. Foods such as rocket, dandelion greens, kale, dill, artichoke and radicchio are all good options. Some people find it useful using something like Swedish bitters prior to or with meals.
Consider a small amount of apple cider vinegar with meals. This may help with people who find the digestion of proteins particularly challenging. Add a tsp – 1 tbsp with water and have at the start or during a meal to assist with digestion.
Reduce foods and review medications containing alpha-glucosidase inhibitors. Certain medications, especially certain medications used for diabetes and obesity can contain these inhibitors. The rational is that those medications can interfere with the breakdown of carbohydrates, unfortunately this can result in digestive upset at the same time. Equally certain foods naturally contain alpha-glucosidase inhibitors, these include spicy foods, beans, onions, garlic, chillies and corn. If you do react negatively to these foods there are also other reasons for this, so don’t assume it is just for this reason. Imbalances of bacteria in the small intestine are common causes of reactivity to a number of these foods as well.
Consider lab testing to rule out infections, inflammation, imbalances or insufficiencies that might lead to issues with digestion and absorption. A high-quality stool test should cover all these areas.
Consider an assessment by an experienced osteopath who is able to assess for tension or structural imbalances that might negatively impact your ability to digest foods effectively.
Stimulate your vagus nerve. The vagus nerve connects the brain to the digestive system. Downregulation of the vagus nerve, often the result of high stress can negatively impact digestion. Here are some tips to help stimulate your vagus nerve.
- Practice diaphragmatic breathing, especially before eating.
- Maintain positive social relationships
- Yoga/Thai Chi & Meditation
- Heart rate variability training
- Gargling
- Humming, singing and chanting
- Take a cold shower
- See an acupuncturist, specific points can help to stimulate the vagus nerve
