Added sugars are not chemically different from naturally-occurring sugars. In other words, the molecular structure of sugar is not different for the sugar added to your food products, versus the sugar inherent (naturally-occurring) in plants… plants like fruit!
In this case, by "added sugars," I mean "nutritive sweeteners" (sweeteners that contribute calories) as opposed to "non-nutritive sweeteners" (alternative sweeteners providing little to no energy, like sugar alcohols and artificial sweeteners).
Wait, wait. You mean sugar from fruit is just as “bad” as added sugar?
To best answer that question, “sugar is sugar.” However, sugar derived from fruit is packaged with other essential nutrients outside of solely carbohydrates. Fruits supply the gamut of macro- and micronutrients – fats, protein, dietary fiber, vitamins, and minerals.
Unlike sugar derived from fruits, added sugar offers nothing other than carbohydrates in the form of mono- and disaccharides. Added sugar does not contain fats, protein, nor dietary fiber. While it may contain vitamins and minerals, the amounts are insignificant and in some cases, the result of manufacturing processes (not naturally-occurring). For this reason, added sugar has earned the descriptor, “empty calories" .
It is for this reason that many food scientists cannot resist the temptations of a proper eye roll with the “Added Sugars” portion of the new Nutrition Facts label. More specifically, in regards to a Daily Reference Value unique to only “Added Sugars,” and not total sugar content (including the inherent sources) .
In many ways, the label is progress and a step in the right direction… perhaps I’m expecting jumps, leaps, and bounds. It’s no secret that if I ruled the world, a Daily Reference Value would apply to the total sugar content of a food product.
What’s so bad about this "sugar" – the added and the inherent kind?
By now, I'm sure you've read a top 10 list somewhere attempting to answer this question. Further, I'm sure 8 of those 10 "reasons" were associations with various, serious diseases ranging from obesity, to fatty liver disease, inflammation, and cancer. While these associations may be founded on legitimate scientific research, the two below reasons are keystones (fundamentals) that can certainly snowball into bigger problems (like those just mentioned). After all, it's the dose that makes the poison.
1. Sugar causes tooth decay.
Bacteria responsible for tooth decay thrive on sugar. Thriving bacteria produce acids which in turn, eat away at tooth enamel and eventually, can cause cavities and gum disease.
2. High sugar intake can result in unhealthful levels of blood lipids.
Higher intakes of sugars are associated with increases in low-density lipoproteins (LDL, commonly referred to as “bad cholesterol”) and triglycerides. Higher intakes of sugars appears to decrease high-density lipoproteins (HDL, commonly referred to as “good cholesterol”). Increased levels of triglycerides and LDL, in combination with decreased levels of HDL, are risk factors for heart disease . For this reason, the American Heart Association has long recommended (before the FDA’s labeling changes) the below Daily Added Sugar Limit (25g for women, 36g for men) .
Sugar is sugar. #biology
Recall, there are four single sugar molecules (collectively referred to as monosaccharides). They are glucose, fructose, galactose, and ribose. These monosaccharides are the building blocks of disaccharides and polysaccharides. Additionally, they are found in all nutritive sweeteners - your added and your inherent sugars. The below is a step-by-step account of how these molecules are processed in one's body.
Step 1. Salivary amylase
Digestion breaks down carbohydrates into monosaccharides, meaning di- and polysaccharides are broken down into monosaccharides. This process begins with salivary amylase (when food enters the mouth). Starch, a component of carbohydrates, is broken into smaller particles (via the salivary enzyme, amylase) and eventually into the disaccharide, maltose (glucose molecule + glucose molecule).
Step 2. Pancreatic amylase
In fact, disaccharides (sugars) are not digested in the mouth. Once departing the mouth, food travels to the stomach. As it pertains to the digestion of carbohydrates, stomach acid inactivates the amylase enzyme, halting digestion. It’s when the pancreas secretes pancreatic amylase into the small intestine that the action happens all over again.
Step 3. Small intestine (maltase, sucrase, lactase)
The bulk of carbohydrate digestion (specifically sugars) actually occurs in the small intestine. Enzymes in the microvilli of the small intestine continue disaccharide digestion, breaking these two-unit molecules into monosaccharides. The below enzymes are responsible for breaking down the following disaccharides into their monosaccharide units: