People often say: “We Are What We Eat.” To a great extent, this statement true. If we eat healthily, it is very likely that our bodies will reflect the nutrition we are feeding it and become strong and healthy. If we are always eating processed junk food, or sugary sweet and high fat foods, we would be consuming empty, unhealthy calories that only make us fat, lethargic and sick.
But how does this happen? How is it that the type and amount of food we consume defines the outcome of our health?
Of course, food is not the only aspects that determine our well-being but it plays the largest role. As living beings, we must eat so that we can provide the “fuel” that the body needs to burn for our daily activities and growth.
How the body gets the “fuel” is by breaking down the foods we eat and absorbing their nutrients through the digestive system to make new cell membranes, blood, hormones and bone marrow. It is from these cells that we grow our skin, hair, nails, sinews, muscles, bones, and the entire brain and neurological, digestive and immune systems. We may not be aware of the actual cell regeneration process but our bodies are constantly repairing, healing and rebuilding themselves. Cell repair, regrowth and regeneration happens mostly at night when we sleep. This is why sleep and rest are so important. It is to allow the body to restore itself so that when we wake up in the morning, we feel “re-fuelled” and refreshed to take on the activities of the day.
Shelf Life of Cells
Our bodies are made up of trillions of different cells and each cell has a “shelf life”, meaning they don’t live forever. A stomach cell lives for about a day or two, a skin cell for about a month and a red blood cell for about four months. Some cells live longer. Cells in the skeletal muscles, for example, take 15 years to regenerate. However, no matter how long a cell will take to reach its individual “expiry” date, the body replaces about 330 billion cells on a daily basis.
How healthy these new cells will be, is directly determined by the food we eat. If our daily meals don’t consist of enough protein, carbohydrates, and all the essential vitamins, minerals and fats, then our bodies will struggle to create healthy cells that can build a strong and healthy body. Unhealthy cells lead to an unhealthy body that will be prone to infection, weakness, lethargy and slow growth.
The Digestive System
How does the body extract nutrients from food and turn them into fuel to create cells and to give us energy? It does through a process called digestion. Many organs are involved in the Digestive System or Digestive Tract, or Gut as it is also called. The organs are the:
Also involved in digestion are the Liver, the Gall Bladder and the Pancreas. They produce substances that further break food down into simpler forms.
The Digestion Process
A: Mouth
You may be surprised to know that digestion begins the moment you put food in your mouth. Your teeth chew the food and grinds them down. While chewing, glands in the mouth produce a digestive juice called saliva. The saliva moistens and softens the food so that it can be easily swallowed. When you swallow the food, it passes through the Pharynx or throat, into the Esophagus.
B: Esophagus
The Esophagus − a long muscular tube located in the centre of your chest – which connects the Pharynx to the Stomach, pushes the food down in waves into the Stomach. This muscular action of contracting and relaxing to push food along in waves is called Peristalsis. You won’t feel this action happening inside your body but it happens, automatically, every time you eat. Peristalsis also takes place in the stomach and intestines.
C: Stomach
Inside the Stomach, millions of glands produce digestive juices that contain Enzymes and Hydrochloric Acid to break down the food particles. The Stomach churns the food into a thick liquid called Chyme. This process doesn’t happen all at once however. It takes place over many hours because different food is digested at different rates. The simple rule of thumb is: the denser the food, the longer it takes to get digested.
For instance, vegetables that contain a lot of water like lettuce, cucumbers, and tomatoes take about 30 minutes to get churned into Chyme and leave the Stomach. Harder vegetables like broccoli or cauliflower take about 40 minutes while root vegetables like potatoes, sweet potatoes and corn take about 50 minutes.
Simple carbohydrates such as plain rice, white bread and simple sugars remain in the Stomach for half an hour to two hours. Proteins such as red meat like beef or lamb remain for three to five hours. Fats may remain in the Stomach for even longer.
This is why our stomachs remain full for longer when we eat a meal containing meat and fat than one comprising just sweets and vegetables.
D: Small Intestine
From the Stomach, Peristalsis pushes the Chyme into the Small Intestine. This intestine is called small because its diameter is smaller than the Large Intestine but actually, it is longer than the Large Intestine and is the longest part of the digestive system. The length of the Small Intestine can vary but generally speaking, the Small Intestine is 18ft to 25ft (5.5 to 7.6 meters) long in an adult, depending on the height and size of the person and the way the intestines were measured.
Did you know that your intestines grow with you? When you were one year old, it was (12ft) 3.8 meters long. At 5 years old, it was (14ft) 4.5 meters long, at 10 years old it would be (16ft) 5 meters long and when you get to be 20 years old, it will be about (18ft) 5.75cm long. The Small Intestines stop lengthening by around age 20.
It is in the Small Intestine that most of the absorption of nutrients from food takes place. This is why food remains in there for several hours.
Once the food is moved into the Small Intestine, two ducts or tubes in the Small Intestine which connect to the Liver (located on top of the stomach and intestines) and the Pancreas (located under the Liver and behind the Stomach) will send digestive juices to digest the food in the intestines.
Juices from the Pancreas help digest carbohydrates, proteins and fats. The Liver, which makes bile, helps to digest fat. The bile is stored in the Gall Bladder, a small hollow organ located just under the liver.
All these fluids break down most of the remains of the food into simple chemicals which enter the bloodstream through the walls of the Small Intestine. The blood carries the chemicals to the body’s cells. The body then uses these chemicals as fuels for energy and growth.
E: Large Intestine
Most of what’s left behind will be liquid as well as indigestible food particles such as plant fibres from the vegetables, grain and fruits you eat. These substances will pass from the Small Intestine into the Large Intestine or Colon. The Large Intestine is much shorter and wider than the Small Intestine and measures about 5ft (1.5 metres) in an adult. The waste material will slowly move through the colon over a period of 10 hours to two days.
The first section of the Colon will absorb fluids and salts. The second section removes more water and turns the waste material from liquid to solid. The last section of the Colon called the Rectum will hold the waste material until it is passed out through the Anus.
The Colon contains a large number of different types of bacteria that help in digesting the remaining food and also in strengthening our immune system. A strong immune system will fight off diseases and prevent us from getting sick.
These bacteria – both good and bad ones − are present in the entire digestive tract but a huge amount and array of them are concentrated in the Colon. It is therefore important to eat lots of gut-beneficial foods such as yoghurt, some types of cheese, tempeh, and other fermented and fibre-rich vegetables so that gut health is promoted which, in turn, bring about a stronger and healthier you.
6 Fun Facts About Your Digestive System
1: You produce about 32 fluid ounces or 946 millilitres of saliva every day. This amount is roughly equivalent to three cans of soda. Your saliva is produced by three pairs of salivary glands inside of your mouth. The glands are located just below each ear, below the jaw and under the tongue.
2: Your Digestive System has a close bond with the Brain. This is called the Gut-Brain Connection. Emotions, such as stress, and brain disorders affect how the Digestive System behaves and vice versa. Diarrhoea, constipation or a stomach ache could be due emotional and psychological issues like anxiety, worry, nervousness and depression. Similarly, if you have stomach troubles like Irritable Bowel Syndrome (IBS) which affects people of all ages including children, you would be prone to mood changes and anxiety.
3: Enzymes in your Digestive Tract are what separate food into the different nutrients that the body needs. There are many different types of Enzymes and they have different names and are located in several places throughout you Digestive System. For example, Amylase breaks down carbohydrates, Protease breaks down proteins and Lipase breaks down fats.
4: Exercise improves the Digestive System. Physical activity increases blood flow to the muscles in the Digestive System. This in turn helps the Digestive Tract massage the food (in a process called Peristalsis) to move along more quickly and effectively through the Gut. At the same time, exercise affects the balance of bacteria in the Gut, prevents the growth of bad bacteria and improves our immunity.
5: Why does your Stomach growl when you are hungry? Stomach growling or rumbling is called Borborygmi and actually, it happens all the time. It is the sound the Stomach and intestines make as food, fluids and gas pass through them. Put your ear to your parent’s stomach and you will hear these sounds going on. However, when the stomach is empty, the sound seems louder. This is because there is no food inside to muffle it.
6: What are hiccups and why do they happen? Eating a large meal too quickly, drinking carbonated drinks or swallowing air, or eating very cold foods immediately after eating hot foods or even getting excited suddenly, can cause hiccups. As the stomach distends or becomes enlarged from the food, the diaphragm, which is a muscle that separates the chest from the Stomach contracts, causing your vocal cords to suddenly close and produce a “hic” sound. Hiccups are mostly harmless and breathing into a paperbag or holding your breath for a short while will usually stop it.