0

Sugar 101 Part II: Glucose vs Fructose

By Dr Monique Thompson

IN the last article I gave a very brief introduction, looking at sugar and what it actually is. I ended by making the point that glucose and fructose both have the same chemical formula (C6H12O6), but are very different to your body.

You may recall the statement that glucose is the body’s preferred source of energy. When you eat carbohydrates (bread, rice, candy, etc) they are ultimately broken down into glucose (a simple sugar) that gets into the blood. Insulin is secreted and the glucose comes out the blood and goes into the cells where it can be used for energy short-term. The body can also store it in our muscle cells or in the liver as glycogen. Many tissues can also use fat or protein as an energy source but the brain and red blood cells, for example, can only use glucose reiterating the importance of this molecule.

The point I would like to make, however, is that storage space in the liver and muscles is limited. About 100g of glycogen can be stored in the liver and about 500g is stored in muscle cells. When this capacity is reached there is no more space in the liver or muscles and the body begins to store extra glucose as fat, which your body views as a source of long-term energy. Consequently, there is no limit to the amount of fat the body can store, because as far as your body is concerned, you may be preparing for a famine. This contributes to the ability of humans to become morbidly obese.

Fructose is another story. Let me start by saying that when fructose is ingested in its natural state – as in when you eat fresh fruits and vegetables – it is not problematic.

The body was designed to handle these relatively small amounts of sugar from those natural sources.

The issue primarily arises with the ridiculously high consumption of artificial/additional fructose, such as in high-fructose corn syrup, which is found almost ubiquitously in this sugar-addicted Western society. Soda, juices, cereals, canned fruits, etcetera are all culprits.

Key differences in how your body responds to fructose include how and where it is used (metabolism), and the hormonal responses it does or does not initiate.

Again, fructose is not your body’s preferred energy source. Unlike glucose who has the brain, red blood cells, liver and muscles to help essentially use it up, fructose is only metabolised by the liver.

In high amounts, fructose eventually puts a burden on your liver – your largest organ. In addition to this, fructose more readily results in the production of fat than glucose.

Adding to this problem of fat production, fructose, unlike glucose, does not stimulate the production of a hormone called leptin, the “satiety hormone”. This is the hormone that tells your brain and body “stop eating!” Glucose wakes up this hormone, which is a great regulator in balancing our energy expenditure. Fructose, however, does not do this. Furthermore, fructose does not cause insulin to be secreted, a hormone that regulates fat in our bodies.

At this point, we’ve seen how both glucose and fructose becomes problematic in making us pack on the pounds, but if the body needs glucose to function properly, why is there such a fuss about sugar?

Keeping in mind that the amount of sugar consumed determines the damage done, and that many individuals consume excessive amounts of both glucose and fructose, the answer to that question has resulted in a third and final part to this article.

• Dr Monique Thompson is the founder of Cornerstone Healing Institute, an integrative family medicine clinic that focuses on educating patients on healthier lifestyles and preventing disease. Contact 356-0083 with any questions/comments or visit www.chibahamas.com for more information.

Comments

Use the comment form below to begin a discussion about this content.

Sign in to comment