Digest The Facts
Digestion is a natural, but it's surrounded by myths.
The Borneo Post - Sunday, 18 November 2001

You can't see it, but you can feet it. Sometimes it rumbles, sometimes it's quiet. Usually it likes what you feed it, but occasionally it can play merry hell. It's your digestive system, and it works for you 24 hours a day. Because you can't see it working, many myths surround the workings of your insides.
Food goes in one end of the body and exits the other end about a day or two later. In between, quite a few changes occur. Once swallowed, food, enters a "warehouse" called the' stomach. Here it receives a hydrochloric acid bath to kill any harmful bacteria you may have eaten. You may still get food poisoning, though, if there is a large number of harmful bacteria.

This acid bath is at least 100 times stronger than the most acid food you can eat. Therefore, the acidity of your food makes little difference to the acidity of your stomach. "Heartburn" occurs when acid "jumps out" of your stomach and into the lower part of your throat causing a burning sensation. It should be called "throat-burn".

The other function of the stomach is to turn everything you have eaten into a liquid paste that can pass into small intestine where the acid is neutralised and most of the digestive process occurs.

The Great Mix Up
It is often said that meat and vegetables can't be eaten together because meat needs acid and vegetables need alkali to digest. Eat the two together and they neutralise the stomach and the, food ferments. This theory is so out-of-date that you might as well argue that the earth is flat, or that witches are responsible for diseases. Everything you eat must first go through the acid of the stomach before being neutralised by alkaline juices in the small intestine. The stomach does not differentiate between meat and vegetables.

A variation on this myth is that you can't eat protein and carbohydrate together. It was known more than 60 years ago, however, that' the pancreas releases enzymes to digest protein, carbohydrate and fat at the same time. This allows humans to eat any food, in any combination, at any time.

Just Add Water
If the stomach contents are concentrated, as is the case with foods of low-water or high-fat content, then it is diluted in small intestine with water either taken from the blood or taken as a drink. This helps digestion because the digestive enzymes are hydrophilic ("water loving").
This dispels the myth that you Shouldn't drink water with meals. Drinking water with meals makes it easier for the digestive enzymes to do their job of breaking down food into small nutrient molecules, which can then be absorbed into the blood. This should be fairly obvious, because fruit and vegetables are about 90 percent water, and our bodies have no difficulty digesting them.

Bacterial Action
What's the best way to keep your digestive system healthy? Simply feed it good tucker. It certainly likes plant food. As the fibre and some leftover starch from plant foods enter the large intestine al the end of the digestive system, they meet around 100,000 billion friendly bacteria that keep your body healthy. These healthy bacteria eat leftover food and produce chemicals that protect against colon cancer.
There has been great interest in the bacteria found in the bowel over the past 10 years. You can eat friendly bacteria, known as probiotics, and it appears they may be the most useful after a dose of antibiotics has killed some of the bacteria, or food poisoning may have flushed them out. Probiotics foods will help re-establish the bacteria in your large intestine
But what is proving to be of greater interest are prebiotics, certain "foods" that are eaten by the friendly bacteria to keep your gut healthy. For example, some foods now have "resistant starch" added. This starch isn't digested, arriving, instead, at the large intestine to be eaten by friendly bacteria.

When to Eat
Will your digestive system work better with three meals a day or a series of snacks? Eating three meals became widespread only in the past 200 years - before this we have eaten mainly when we could get hold of food. It's what you eat, not when you eat, that will have the greatest effect on the health of your insides.

The End Result
At the end of your large intestine (colon), your waste (bacteria, dead cells, water and whatever bits of food the bacteria have left behind) is neatly packaged waiting for you to grab the newspaper and head towards the little room.

Your Digestive System in Action

1. Mouth
The pleasure zone of the digestive system. Glands secrete saliva, allowing your tastebuds to enjoy the flavour of food. Saliva contains amylase, an enzyme that starts the process of digesting starch, while lubricating food so it slides easily down the throat. Saliva is good for oral hygiene, as it flushes away food particles, while repairing damage caused by acid produced by carbohydrate-eating bacteria in the mouth.

2. Throat
Also called the oesophagus, this connects your mouth to your stomach. When you swallow food, it passes down the throat, past a sphincter and into the stomach. This sphincter closes so food doesn't return to the throat. Sometimes this does occur - heartburn - and is more common in people with a lot of abdominal fat, which can push stomach contents into the throat.

3. Stomach
A one-litre chamber where food is stored before it enters the small intestine. The stomach turns all food into a liquid, while also adding to help kill any nasty bacteria you may have swallowed. The acid activates the enzyme pepsin that starts digesting protein. The stomach also secretes intrinsic factor, a substance that is needed to assist the absorption of vitamin B12 in the small intestine.

4. Small Intestine
This is where most of the digestion occurs, mainly through the action of enzymes produced by the pancreas. Once food is fully digested, the nutrients are then absorbed in the six metre-long small intestine. There are adequate amounts of digestive enzymes produced after each meal and snack. Some people don't produce much lactase (the enzyme that breaks down the milksugar lactose) after the age of five. They are called lactose intolerant, and are unable to handle large amounts of milk.

5. Pancreas
The pancreas is a gland that lies just behind and below the stomach. It produces enzymes to break down fats into fatty acids. carbohydrates into sugars and protein into amino acids. All of the enzymes are released at the same time, so the body can easily deal with protein, fat and carbohydrate at the same meal.

6. Liver and Gall Bladder
The liver produces bile, which is then stored in a 40ml sac called gall bladder, situated underneath the liver. Bile breaks down fat into small globules, very similar to the action of a detergent, for easier digestion by the fat enzymes. If you have had your gall bladder removed. you may have to eat a lot less fat to compensate for the reduced amount of bile you are able to secrete. The liver is also responsible for processing nutrients after they have been absorbed from the small intestines

7. Large Intestine
As most digestion and absorption has occurred in the small intestine, what reaches the large intestine is mainly indigested food residue, and small amounts of undigested starch and protein, along with fluid and salts. Much of the undigested food is eaten by friendly bacteria m the large intestine. Of the 600-1,000ml that enters daily from small intestine, only 200g ends up-as faeces.


Added: Monday, 04 February, 2002 04:17 PM