UNDERSTANDING THE DIGESTIVE SYSTEM
We are what we eat and it is thanks to the prowess of the digestive system that this is possible. Endowed with an extraordinary machinery of great complexity, the understanding of its functioning is fundamental.
HOW DOES THE BODY DIGEST FOOD?
THE DIGESTIVE SYSTEMOpen tab
Even if the subject seems "déjà vu" and not necessarily engaging at first sight, one must be wary of preconceived ideas. The human digestive system is a true marvel of a food demolition factory, a recovery plant for spare parts (nutrients) and a waste treatment facility. The processes used by the body are as much mechanical and physical as they are chemical. Passing through a digestive path almost 8 metres long, the food is digested through a succession of distinct stages.
Functional digestive disorders (dyspepsia) are caused by a malfunction of the digestive system. Most of them occur in the stomach (loss of appetite, nausea, burning, hiccups, bloating) and intestines (bloating, intestinal gas). Not to mention the causes, which are multiple when experiencing such symptoms, it is important to take appropriate action whether it is through diet, dietary supplements or by changing certain habits. To choose wisely, it is important to know the route taken by food through the digestive system and the mechanisms involved in each stage of the digestion process.
The jaw and teeth mechanically reduce food into small pieces before it is transferred from the esophagus to the stomach. Teeth are in the front line of the digestive process, which is why it is important to keep them healthy and maintain an optimal oral flora to prevent plaques and cavities.
The passage through the mouth also allows saliva to start the first digestive process. Saliva contains amylase, an enzyme that reduces starch to glucose, a nutrient that is essential for the body's functioning.
From the pharynx, food is then transferred through the esophagus by gravity as well as peristalsis in the stomach. The stomach has a dual function: the start of digestion and the progression of the food bolus to the intestine. The contractions of the muscular wall of the stomach ensure the mixing and stirring of food and gastric juice. The food bolus is thus kneaded to produce a thick substance called the gastric chyme.
Digestion in the stomach mobilizes lipase, an enzyme that breaks down lipids (fats) into fatty acids and then into glycerol, pepsin, an enzyme that converts proteins into peptides and polypeptides, and hydrochloric acid, whose main activity is to destroy bacteria in food.
The digestion process in the stomach takes 1 to 2 hours. The contractions of the stomach then allow the progression of the nearly digested contents towards the pyloric sphincter (the muscle which ensures the closure of the pylorus) which, when it opens, allows the transfer to the duodenum.
The intestine is 13-19.5 feet (4-6 meters) long and consists of three parts: the duodenum, the jejunum and the ileum. In the first part there are two ducts, one from the pancreas and the other from the liver and gall bladder. The bile transported by the latter allows the digestion of fats. The pancreas, then again, is a factory of enzymes which allows the digestion of fats, as well as proteins and sugars.
At the same time, and throughout the small intestine, the body begins to absorb nutrients. This part of the digestive tract is covered with myriads of folds. This gives it a huge absorption surface of about 2,691 square feet (250 square meters)….the size of a tennis court!
It is in the intestine that fatty acids, amino acids, vitamins, proteins, fats and sugars are absorbed. Its proper functioning is vital for the body. It is important to maintain a balanced and healthy bacterial flora in the intestine in order to preserve it and promote optimal absorption of the nutrients the body needs.
The colon is the last stage before excretion. Approximately 4.92 feet (1.5 meters) long, the colon is a water storage and retrieval area. At this stage of digestion, all nutrients have been absorbed. All that remains is dietary fiber that the body cannot digest. Most of it comes from the cereals, fruits and vegetables that have been ingested. They are then expelled from the body in the form of faeces (composed of water, many bacteria and dietary fiber).
4 TIPS TO DIGEST WELL
1. TAKE MORE TIME TO EATOpen tab
The basis for a good digestion is to eat slowly. Larger pieces swallowed too quickly cause the pylorus to close, which acts as a door between the stomach and the small intestine. The stomach then has to do more work to reduce the food into small particles. Eating too quickly stimulates the production of gastric juices, which are very acidic, burn and give a feeling of heaviness.
If you wish to take your time eating a meal, all the tricks are good. Eating at the speed of the slowest person at the table, taking small bites, chewing longer, avoiding to eat in front of the television or splitting up food intakes are the most common methods. The key is not to overload the digestive system quickly so as not to affect its proper functioning and avoid unpleasant symptoms.
2. AVOID CERTAIN DISHES AND FOODS AND ENCOURAGE OTHERSOpen tab
Some foods are known to cause problems that can be accompanied by unpleasant symptoms. Although it is not necessarily useful to ban them completely from the diet, it is recommended not to overindulge in them and to limit their quantities.
The caffeine contained in coffee has the effect of increasing gastric acidity, which can cause stomach burns and favor the development of more serious pathologies in the long term (e.g. ulcers). Certain spices and chili peppers can cause the same type of symptoms. The same applies to alcoholic drinks (especially white wine) and vinegar. Finally, high-fat foods are known to be difficult to digest and their metabolism to be slower. Fried foods, cold meats, cheeses, butter or ice cream should therefore be eaten in moderation.
To improve digestion, fiber intake should be promoted. They are found in fruits (apricots, apples, pears, raspberries, prunes ...), vegetables (artichokes, peas, carrots, beets ...), legumes (lentils, beans ...) or seeds (flax, wheat or oat bran, spelt ...). Consuming too much fiber can irritate the digestive tract or ferment in the colon, if the intestine is not used to ingesting fiber, so it is always best to manage your fiber intake and drink lots of fresh water.
3. TAKING PROBIOTICSOpen tab
Probiotics are bacteria or yeasts (Lactobacillus, Bifidobacterium, Streptococcus...) naturally present in the body. These living micro-organisms participate in digestion and have many benefits. They allow a better regulation of the intestinal transit, reduce the frequency of diarrhea and the risk of the appearance of symptoms such as irritation of the intestinal wall. Probiotics are also known to promote the development of a balanced intestinal flora and reduce the risk of infection from opportunistic pathogenic bacteria.
They can be taken in the form of food supplements or in the diet. The best known are brewer's yeast and lactic acid bacteria which are also found in certain yoghurts.
4. EXERCISEOpen tab
Exercise promotes the proper flow of food through the digestive system and improves its overall functioning. The circulation of blood in the digestive system increases, which promotes digestion. The repeated contraction of the intestinal muscles allows for faster digestion while promoting better absorption of nutrients needed by the body. Serious scientific studies have also shown that frequent exercise reduces the risk of constipation and takes care of the gastrointestinal mucosa.