Sweet Talk – How Does Human Body Digest Food?

By Sheila Kun RN, BSN, MS, CPN, FCCP

Two weeks ago, for those who might miss reading our discussion on “Sweet Talk”, we began exploring what are the many faces of sugar. We recognize that sugar can be simple or complex and that their names usually end with “ose”. We also understand that sugar is part of the carbohydrates in our food. This week, I fell in love with what Aubri John wrote about how the human body digests food. Below is his abstract. Enjoy!

The term “sugar” is commonly associated with sweet treats or a white crystalline powder you add to foods; however, sugar is also a classification of carbohydrates. The varying chemical structures of sugar include single units, double units, and multiple units, which are: No matter the chemical structure of a sugar chain, your body digests all sugars in a one step process.

Sugar Digestion

Once you swallow food, it travels down your esophagus to your stomach where digestive juices dilute it for later movement through the rest of your digestive tract. Sugar and carbohydrate sugars pass through your stomach rather quickly to begin the process of breaking down in your small intestine. All forms of sugar break down into the smallest possible sugar molecule with the help of digestive enzymes housed in the lining of your small intestine. Once sugar returns to single molecule form, it is absorbed through the intestine into your blood as glucose. Your pancreas secretes the hormone insulin to retrieve the blood glucose and distributes it to different cells throughout your body for use as energy.

Single and Double Units

Fructose, dextrose and galactose are common single units found in foods like fresh fruit or milk. Sucrose, lactose and maltose are made of two single chains, like those found in table sugar, germinating grains and dairy. When you eat these types of sugar-containing foods, your digestive system breaks the sugar unit down into a single molecule and converts it into glucose. The single and double unit sugars breakdown and quickly get released into your bloodstream, which may cause a quick “sugar rush” followed by a crash, depending on the food source eaten. For instance, a spike and crash occurs from eating sugary candy, but if you eat a strawberry with natural sugar, your blood glucose sustains longer because the fruit also contains fiber, which slows the digestive process.

Multiple Sugar Carbohydrates

Complex carbohydrates contain multiple sugar chains which are high in fiber and indigestible. When you eat wheat bread or oatmeal, the sugar in the food breaks down into a single molecule dispersed as glucose into your bloodstream, but these types of foods also contain a high amount of indigestible fiber. Essentially, the sugar is digested the same way because it is turned into a single unit before conversion to glucose. However, the complex carbohydrate-containing food has additional nutrients your body uses in the digestive process.

Healthy Sugar Sources

The healthiest sugars come from complex carbohydrate-containing foods or fresh fruits and vegetables. These food sugars keep your blood glucose sustained to energize you throughout the day. The occasional sweet treat with refined sugar is fine with a well-balanced diet but gorging on junk food may leave you feeling irritated and craving more sugar-filled treats if you do not choose nutritious foods. Opt for whole grains instead of processed white grains, which generally have added sugars. Choose raw produce instead of canned or frozen varieties and limit your use of table sugar.

carb-control-1.pngWhen we digest sugar, enzymes in the small intestine break it down into glucose. This glucose is then released into the bloodstream, where it is transported to tissue cells in our muscles and organs and converted into energy.

Your home work for today from the Care Ministry: Give an example of a simple and complex sugar. Understand the concept of a “sugar rush”.

The Care Ministry welcomes your comments/suggestions: kunlouis@gmail.com