Carbohydrates - Part 1
Carbohydrates 101
This is the story about why the body is so attracted to carbs, what they do in the body…and tells the tale about why carbs were vilified and why they were totally wrong.
All carbohydrates are made up of 3 simple sugars (saccharides):
Glucose: Provides your cells with energy. It travels through the bloodstream and needs insulin to open up the cell to allow the glucose to be absorbed.
Fructose: This is your body’s backup energy source. It first needs to be converted by the liver into glucose, so the body will store extra if the bloodstream already has enough glucose.
Galactose: A minor player found only in milk. Before humans began to drink cow’s milk, our galactose consumption ended after weaning.
…the story from here will mostly be about glucose and fructose since there’s not a lot of galactose in our life.
These single sugars (saccharides) are easily digested and absorbed because they don’t need to be broken down before hitting the bloodstream. Nature solves this problem by always accompanying single saccharides with fibre to slow down the absorption. Fruit is the main source of single saccharides (both glucose and fructose), but the concentration of saccharides is low and there are lots of nutrients and fibre to help the body.
This is why fruit can feel so good when your energy is low :).
The problem today is we’ve been adding glucose and fructose to loads of foods, including drinks that don’t need any digestion.
High Fructose Corn Syrup (HFCS) is 50/50 glucose and fructose. Unbound and easy to digest, especially if it’s in a drink. Most sugary drinks have more than enough glucose to cause a blood sugar spike, so a lot of the fructose is stored instead of converted. First, the extra fructose is stored for later in the liver. When those stores are full, the body stores the extra fructose as fat.
…this is why fructose gets a bad rap, and that’s partially true. It depends on the source and how it’s consumed. There’s a HUGE difference between a piece of fruit and a bottle of coke. Or even between a piece of fruit and a glass of juice. A glass of orange juice has the sugar content of 7 or 8 oranges, but without any of the fibre to slow down the digestion.
Now let’s move to the disaccharides:
These simple sugars combine together to make 3 di-saccharides (2 sugars) -
Sucrose = Glucose + Fructose (found in veggies, sugar cane, some fruits, maple syrup, and refined white sugar)
Maltose = Glucose + Glucose (found in grains)
Lactose = Glucose + Galactose (found in milk)
The body has to work a bit harder now to pry apart these disaccharides. When found in nature, the food includes all of the building blocks for the body to make the necessary enzymes to break these apart. Most of these foods also come with a lovely dose of fibre to help slow down digestion.
The enzyme to break down lactose (lactase) stops being made by our pancreas early in childhood. Sometimes the gut bacteria take over and continue making this enzyme, but those with lactose intolerance aren’t able to. The bloating and digestive issues are the results of undigested lactose in the intestinal tract.
Refining grains and sucrose-rich food (like sugar cane and sugar beet, the main sources of refined sucrose in our diet), strips these foods of the nutrients needed to make the necessary enzymes for digestion. The body has to grab them from other spots, leading to B vitamin and magnesium deficiencies. And, the fibre is missing, so the sucrose digests much faster than in nature.
And…there’s another little hitch with refined forms of sucrose. Certain bacteria and yeasts in the gut love love love undigested sucrose. Candida is a yeast that’s most famous for consuming sucrose, but it’s just one player in the gut. Many not-so-great strains feed on sucrose.
These bacteria love it so much that they will ask for it. Your gut bacteria may be able to change your taste buds and send signals to your brain, asking for these delightful forms of sucrose. So…your cravings may be partially driven by some rogue bacteria.
Now, let’s get into even longer chains :)
Polysaccharides – long chains of saccharides
This is the main carb found in nature :)
Before we started refining grains and sugars, most of the carbohydrates that humans ate were long chains of sugars called polysaccharides. Whole grains, beans, and veggies are full of these very long sugar chains.
Note: Refining grains and sugars was originally done to increase shelf-life. At the time, little was known about nutrition. Carbohydrates weren’t ‘discovered’ until the mid-1800s and the first vitamin was isolated in the early 1900s. We didn’t know then what we know now, that removing the fibre, removing key vitamins and minerals, and breaking down the polysaccharides into smaller chunks can be harmful to the body.
Digesting a polysaccharide is very complex. First, your body needs to isolate it from the fibre. Second, it needs to break down the chains into individual sugar molecules (glucose, fructose). This takes time, which allows your body to extract glucose from these foods slowly over hours instead of minutes.
And, it needs enzymes to break the bonds of the long chains. This is the part that gets tricky nowadays. Whole food comes with all of the nutrient-building blocks needed to digest said food. But, refining sugar and grains strips away those nutrients and, over time, the body can’t make the enzymes needed for digestion. This is one of the reasons you may start feeling bloated after eating certain foods, foods you’ve eaten for years without a problem. The bloating is a sign that the chains aren’t being fully broken down and are instead being fed to some rogue bacteria who like to burp up gas.
And this brings us to…
Why The Anti-Carb Theory is SO Popular (and wrong)
The theory is (in a nutshell): Carbs trigger a blood sugar spike and the resulting insulin response triggers the body to store fat. So, get rid of the carbs then your body will be happy!
But, as you can imagine, now that you know the chemistry of carbohydrates that this is a tad simplistic. And, the body LOVES to have easy access to glucose. A low-carb diet makes the body convert protein into glucose, and it really doesn’t like doing that. It’s an okay backup plan, but why can’t we just eat carbs? Especially when they’re in your cupboard?
In nature, carbs don’t cause a blood sugar spike. Period. It’s what we’ve done to carbs that cause all of the problems. Plus, carbs are the major source of vitamins and minerals, so a very low-carb diet is hard to balance nutritionally.
So, instead of avoiding all carbs, enjoy the carbs found in nature! Full of fibre, nutrients, and super long chains of saccharides that the body has to break down to access the sugar!
Now that you have a handle on the different types of carbs found in food, let’s look at how the body uses carbs :).
Got any questions or comments? Comment below, jump to our private Facebook Group, or the Ask Lisa page :).