Get to Know Your Sugars

Because They Can Be Surprisingly Complex... or Simple

We've all heard of them - fructose, glucose, lactose, and sucrose. Perhaps we all even know that these are sugar molecules, but do we really understand them and how they impact our health?

Let's get the easy one out of the way, first. Sucrose, also known as table sugar -- yes, exactly the same one in the little bowl sitting next to the coffee maker -- is formed by bonding one fructose molecule with one glucose molecule. Because it's formed from two other sugars, sucrose falls into the category of disaccharides. All sugars are different combinations of Carbon, Hydrogen, and Oxygen, and are differentiated by the number and arrangement of atoms.

Lactose is another disaccharide, containing a glucose molecule bonded to a galactose molecule. Some readers may be especially familiar with this one's capacity to cause intolerance and upset stomach. Did you know it's actually just one of many sugars that can cause this type of reaction? Read about FODMAPs sometime, and see if these might be causing you problems as well.

The other two I mentioned above are monosaccharides, meaning they are composed of a single sugar molecule. They are also called "simple sugars". Our body breaks down more complex sugars in order to make simple sugars because that is the form that we can quickly convert to energy.

Glucose is the form of sugar that our bodies use most of the time for energy, but that doesn't mean you need to eat glucose all the time! All sugars and carbs are eventually broken down or converted by our body to this form. Even foods that are not thought of as carb-y, such as vegetables, will have plenty of carbs to add to your energy stores.

There are many processes at play in converting food to energy, and not all carbs are equal in their impact on blood sugar. In fact fiber is a type of carbohydrate that is not digestible and can actually have a positive impact on reducing blood sugar spikes by slowing down digestion and improving the health of our gut microbiome. Unfortunately, that's not what we're focusing on today!

Photo From Shutterstock / chromatos - Molecular structure of different kinds of sugar

Glucose is often found bound to other sugars in foods, and may be found within longer-chain polysaccharides or bonded to one additional sugar molecule as in the case of sucrose and lactose. Lactose, the sugar naturally occurring in milk and dairy, contains one glucose and one galactose molecule.

Another name for glucose is dextrose, because the molecule is "dextrorotatory". This concept has something to do with the way the molecule affects a plane of polarized light. Seems like an oddly specific way to categorize a substance, but scientists are gonna do what scientists do!

What's important for our purposes is that many processed food labels will try to sneak in additional sugars under this name, even in products that claim to have "0g Added Sugar."

Other names that actually mean sugar include, but are not limited to:

• beet sugar
• blackstrap molasses
• buttered syrup
• cane juice crystals
• cane sugar
• caramel
• carob syrup
• castor sugar
• coconut sugar
• date sugar
• demerara sugar
• fruit juice
• fruit juice concentrate
• golden sugar
• golden syrup
• grape sugar
• honey
• invert sugar
• maple syrup
• molasses
• muscovado sugar
• panela sugar
• rapadura

Sorry, this list just goes on and one… and there's more:

• refiner’s syrup
• sorghum syrup
• sucanat
• treacle sugar
• turbinado sugar
• barley malt
• brown rice syrup
• corn syrup
• corn syrup solids
• high fructose corn syrup
• dextrin
• dextrose
• diastatic malt
• ethyl maltol
• glucose
• glucose solids
• lactose
• malt syrup
• maltodextrin
• maltose
• rice syrup
• crystalline fructose
• fructose
• D-ribose
• galactose

Some of these are obvious, but many are not, and it's too long of a list to memorize. You'll catch most of them if you watch out for a few key words or letters in the ingredients list.

• The ingredient includes syrup, sugar, malt, molasses, or juice
  • syrup or sugar as in "brown rice syrup" or "beet sugar"
  • malt, or molasses as in "barley malt" or "blackstrap molasses"
  • juice as in "fruit juice concentrate" or "cane juice"
• Any part of the ingredient name
  • ends in -ose, as in "glucose solids" or "maltose"
  • includes dex as in "dextrin", "dextrain", "maltodextrin"

You may be thinking "juice"? What's wrong with juice! It's fruit. Isn't that good for you?

While fruits in their whole form can contain a lot of valuable vitamins and nutrients, and the solids from the fruit can provide some fiber, even the best of fruit is still packed with sugar. In the form of juice, it's a concentrated dose of fructose that should be treated as well, a treat, rather than a daily component of a healthy diet.

If you don't believe me, check out this nutrition label straight from Welch's for their non-GMO, no-sugar-added, 100% Juice Apple Juice.

No matter how you frame it, 53g of sugar in one serving is a lot. A donut, for reference, has only 10-15g of sugar. An apple still has 19g of sugar, but also has a few grams of fiber, and more importantly it provides a higher feeling of satiety than juice. While you are unlikely to keep eating apples all day, it's not unusual for someone to drink juice throughout the day thinking they are just enjoying some flavorful hydration.

Another category to be aware of is the sugar alcohols. These are often used as a substitute for sugar since they still taste sweet but are not absorbed by the body in the same way as sugars themselves. These usually end in -itol and include mannitol, sorbitol, xylitol, lactitol, isomalt, maltitol. While they occur naturally in foods, such as sweet potatoes, they are used in much higher concentrations as artificially sweeteners in low-sugar foods, and can still have a negative impact on health.

If you don't want to spend time scanning ingredients, another strategy you can use is to check the nutrition label for Sugar and Added Sugar, but be aware that even that seemingly-straightforward strategy can have loopholes. For example, if there is 0.5g or less of sugar per what the manufacturer calls a "serving" of the food, they are allowed to round down to 0g. Since the serving size on many prepackaged foods is laughable, this can leave you unintentionally consuming substantial amounts of this "rounded-out" sugar.

Besides the obvious potential to spike blood sugar, sugars carry some other dangers to be aware of. Glucose is the fasting blood-sugar spiking molecule, since it's already in the form that our body can burn. If can be immediately absorbed through your small intestine and doesn't need to be processed or broken down. This is also what is measured by diabetic testing devices, including Continuous Glucose Meters (CGMs).

Fructose is also absorbed directly into your bloodstream, but needs to be converted by your liver into glucose before it can be used. This means that it doesn't immediately spike your blood sugar. However, it can have a negative impact on your blood-lipid levels, increasing triglycerides and LDL cholesterol. Ultimately, long-term consumption of high levels of fructose increases the risk of metabolic disfunction, and can lead to chronic disease such as nonalcoholic fatty liver disease.

This is largely where the danger in processes foods comes from. Not only are these sugars present in much higher quantities, but the foods are designed to be highly palatable (read: delicious, maybe even addictive), but they also tend to be things that are not filling or satisfying.

Since so many sugars can be hidden in food, and overeating sugar can cause a lot of chronic health issues over time, the best defense is awareness. Sure, you'll celebrate some life events with a slice of cake, but if stick to just the intentional sugars that you've decided are worth the risk, over time, you'll greatly improve your health, energy, and capacity to live your life as you choose.