The Human Digestive System
And the Effects of Aging
You have, by no doubt noticed that your digestive system doesn't
function as well as it used to. Do you suffer from heartburn, gas,
nausea, diarrhea or constipation? This is your body telling you that
you need make changes in both your eating habits and your
The function of the human digestive system is to break down food and
drink so their nutrients can be absorbed to provide nourishment and
energy throughout the body. As we age the digestive process slows down
and the body may not get enough nutrients. This can lead to a decline
of other body systems and disease.
Successful aging depends on a well
functioning digestive system. There are a number of steps we can take
to improve digestion. But first, let's gain a basic understanding of how
the digestive process works:
- Digestion begins in the mouth with the chewing of food
(mastication). The teeth start the process with the help of saliva.
Saliva contains some enzymes which begin the breakdown of starches and
fats while they are still in the mouth.
- With each swallow the food is forced down the esophagus
and travels to the stomach, by means of muscular contractions
(peristalsis). Food and acid is kept from flowing backward by circular
bands of muscles called esophageal sphincters.
- In the stomach the
food is broken down into small particles by acids and enzymes (secreted
from the pancreas and liver), into proteins, fats and carbohydrates.
The stomach is the primary place where proteins are broken down.
- These particles then enter the small intestine.
Nutrients that the body needs for energy, growth and repair are
absorbed through the intestinal walls and transferred to the liver for
- At the end of the small intestine all that is left is water and waste material. This material now enters the large intestine, whose main function is to remove the water from the waste products and return it to the body.
- At the end of the large intestine is the colon, where the waste material sits until it leaves the body through the anus.
How does aging affect the digestive system?
As we age, the digestive process becomes less efficient:
- In the mouth, food may not be properly broken down due to missing teeth or
gum problems as well as lowered saliva production
- The lower sphincter that regulates the flow of food from the esophagus into the stomach, can weaken resulting in reflux, a back flowing of food or acid (heartburn)
- Loss of muscle tone causes food to move more slowly along the digestive tract
- The stomach becomes less elastic and cannot hold as much food
- The production of acids and enzymes declines.
A decline in the production of lactase, an enzyme that digests dairy
products can lead to lactose intolerance, a condition that causes
bloating and gas when milk products are consumed
There are a number of steps you can take to regain a healthier digestive system. For more information and helpful tips see:
How to Improve Digestion
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