Sugar – What is it made of, and is it really bad for you?

sugarSugar, the tiny white crystals that revolutionized eating starting in the early 1800s, is one of the most discussed and debated topics in nutrition.  Some say sugar is downright poisonous to the body while others say consuming moderate amounts is OK, and even part of a healthy diet.

Let’s take a closer look at what sugar actually is, and its effects on the body.

The term “sugar” is a generalized reference to chemically-related, sweet tasting substances that naturally occur in all plants.  It is basically the end product of photosynthesis.   Sugar cane and sugar beets are the only plant species with a high enough concentration of sugars for commercial extraction and processing.

Sugar is a carbohydrate, consisting of carbon, hydrogen and oxygen.   Simple sugars are called mono-saccharides which include glucose (also called dextrose), fructose, and galactose.

Di-saccharides are two monosaccharides connected together molecularly and include sucrose, maltoseand lactose.

Sucrose, which is what table sugar is, is comprised of glucose and fructose.  It is derived from sugar cane and sugar beets.

Lactose, or milk sugar, is comprised of glucose and galactose.

Now, do you have that all straight?

The sugars that should concern you the most are sucrose, fructose and glucose; mostly because these are the forms that comprise the bulk of total sugar consumption in the world.

You will find added sugar (sucrose) in most manufactured food products, and not just dessert foods and other sweets.  Just about all sauces, condiments, soups, cereals, yogurt, flavored drinks and processed meats include added sugar.  One teaspoon of table sugar weighs about 12 g and contains about 48 calories.

Fructose is the sugar that naturally occurs in fruit and honey, and is the sweetest of all the sugars.  In fact, high fructose corn syrup (HFCS) is made by hydrolyzing  corn starch, which breaks down into corn syrup containing mostly glucose, and then adding enzymes to convert some of the glucose into fructose to get the desired sweetness.  Depending on the product, HFCS can contain 55%, 42% or 90% fructose.  The higher the percentage, the sweeter.

HFCS is the preferred sweetener for food manufacturers because it is cheaper than table sugar, due to government subsidies for corn farming.  It is widely used to sweeten beverages (sodas including Coke and other flavored drinks), breads, and snack foods.

Now the question:  what does your body think of sugar?

When sucrose is consumed, it breaks into its components of glucose and fructose.  Glucose, which is what is measured when one gets a blood sugar lab test, is metabolized, or can be metabolized, by all cells in the body to use as fuel.  It is a quick source of energy, which comes in handy in those situations that require it (sports, doing heavy labor, mental tasks, etc.).  Glucose that is not used is converted intoglycogen and stored in the liver and skeletal muscles.  Think of glycogen as a reserve gas tank in your body that will release fuel when the normal supply (blood glucose from the diet) is out or low.

Fructose, on the other hand, is treated differently by your body.  Did you know that fructose does not significantly raise blood sugar?  When consumed, fructose is directly metabolized in the liver, skipping the rest of the body, into free fatty acids, which eventually convert to triglycerides and stored as fat.

According to Dr. Robert Lustig, a prominent researcher on the subject of sugar metabolism, fructose metabolism promotes fatty liver disease, where these free fatty acids deposit in the liver and skeletal muscles as tiny fat droplets.  It’s the same pathology seen in alcohol-related fatty liver disease, but without the alcohol.  He says another problem with fructose is that it does not not suppress the hunger hormone ghrelin like glucose does; meaning, you don’t know when you’ve had enough, resulting in over-consuming the fructose-laden food.  That’s probably why it’s easy for a lot of people to finish an entire Big Gulp at the 7-11!  Prolonged over-consumption leads to insulin insensitivity, a precursor to Type II diabetes.

Side note:  some believe that this characteristic of high fructose corn syrup– it’s tendency to not trigger fullness, resulting in eating more of the product– is the real reason why big food manufacturers like using it in their products.

So, does sugar deserve all the scorn it is getting in the media?

Ideally it is best to avoid processed sugar, especially fructose.  You get enough sugar from eating plants and fruit; and also from grains and starches, so any added sugar in processed foods represents excessive, unnecessary calories.

However, what is life without an occasional dessert?   The key word is occasional.   Go on ahead and treat yourself to that ice cream cone, with the understanding that you are doing it just for the taste, not for the nutrition.   Once a week is reasonable.   If you find yourself eating sweets as a regular, integral part of your diet, you are setting yourself up for problems.  This includes sodas, flavored drinks, pastries, and candy.  These foods can easily add hundreds of excess calories a day, most of which will go directly towards making fat cells.

Eliminating or sharply reducing processed sugar from your diet will do wonders for your health; just ask Alec Baldwin, who lost 30 pounds in four months and is keeping it off to this day by doing this.

This was originally posted in my previous site,

Posted in Nutrition.