This is the first in what is going to be a 3 part series of
blogs. Sugar is a complicated topic that warrants a long-winded explanation. Since
no one wants to read a long-winded explanation, I am splitting it up into parts
for you.
This post is all about what a sugar actually is. It will set
you up for understanding sugar metabolism better. Its science-y, so bear with
me while I nerd out on bonds and molecules.
To be clear, I will not be talking about artificial
sweeteners here. Artificial sweeteners such as sucralose, aspartame, cyclamate,
saccharin and sugar alcohols (sorbitol, xylitol, etc) are chemically altered
sugars that have a whole host of different health and metabolic implications.
All carbohydrates break down into simple sugar molecules.
The most basic sugar molecules are glucose, fructose and galactose. Each of
these molecules has the same chemical formula C6H12O6
but they have slightly different shapes, which allows them to interact
differently with the cells in your body.
In foods, sugars are combined with each other to make longer
chains of carbohydrate.
- sucrose — common table sugar = glucose + fructose
- lactose — major sugar in milk = glucose + galactose
- maltose — product of starch digestion = glucose + glucose
Starch is made up of long chains of linked glucose. When they
form a straight chain, it is called amylose. A highly branched glucose chain is
called amylopectin, which is the chief energy storage unit in plants.
In animals a molecule similar to amylopectin is used to
store energy. It is called glycogen. Glycogen has more frequent branches in its
glucose chain than amylopectin.
Here is why all of this is important. When your body uses
sugar for energy -- actually when it uses anything for energy -- it breaks it
all the way down to carbon, oxygen and hydrogen atoms. The process of getting
down to these tiny atoms is long and complicated involving many enzymes and
cellular checkpoints along the way.
The SHAPE and SIZE of the different sugars, as well as the
way that the sugar molecules are linked to eat other will directly affect what
enzymes will break the sugar down, how quickly the sugar is broken down and how
easily your body can use the sugar for energy.
All of these things affect your blood sugar. Blood sugar
impacts insulin levels. Insulin, in turn, affects all of your other hormones
including cortisol, leptin, glucagon, ghrelin, thyroid hormone and sex hormones.
All of these hormones impact fat storage and metabolic rate.
How you metabolize sugars will also determine whether or not
they cause an inflammatory response in the body. Certain sugars or products of
sugar metabolism can cause oxidative damage in your body and inflammation.
That is enough science for today.
Next week, we will start to talk about why some sugars are
better and worse for you.
How we determine if a sugar is ‘good’ or ‘bad’ is by looking
at how the sugar impacts hormones, metabolism and if it does or does not cause
oxidative damage and inflammation. Lastly, we will factor in the nutrients that
come along with some sugars in their natural forms.