Folks, please join me for a three-part series in which I separate the wheat from the chaff (and myth from fact) on everybody’s favorite topic: sugar. We’ll explore what it is, how it is digested and absorbed, what happens to it in the body, alternative and artificial sweeteners, and the science (or lack thereof) behind sugar’s role in a host of modern ills. If I survive the Sugar Wars, look for more fact-based discussions on wheat & grains, gluten, protein & low-carb diets, calories and body weight, Paleo and more. Fasten your seat belts – it’s going to be a bumpy ride! ~Kaela, a.k.a. the Data Diva
The Sugar Series
This same exact scenario played itself out back in the 80′s: the circling of the wagons, the angry mobs with virtual pitchforks and torches, the demands from an outraged public for food products free from the demon seed that was killing us all. Except, back then, fat was evil; fat was toxic; fat was destroying our health. Specifically saturated fat, but in typical American fashion, “good” fats got tossed out with “bad fats” until no one wanted to eat any fat at all. The USDA Dietary Guidelines from 1980, the first year such guidelines were published, are fascinating in that the basic advice hasn’t changed in 35 years: eat a variety of foods; maintain an ideal body weight; avoid too much fat, sugar and sodium; eat complex carbohydrates and fiber; and drink alcohol in moderation. But the devil is in the details as they say. “The major health hazard from eating too much sugar is tooth decay.” Oh, the innocent 80′s. How I miss you.
Back in the day, sugar was relatively easy to spot: it was in candy, of course, and cookies, cakes and ice cream, and we all knew that Froot Loops were neither nutritious nor good for us (hence we wanted ‘em even more). But these days, sugar is in everything: crackers and bread, chicken stock and tomato sauce, yogurt and milk and every frozen dinner you can find. But do you know why? Because sugar acts as a preservative and a flavor & texture enhancer for all sorts of processed foods. Much like fat does. So, when we demonized fat in the “heart-healthy” 80′s & 90′s, it was replaced in the convenience foods we demand with sugar (and salt, but that’s a story for another day). Good old innocent nothing-to-see-here-but-tooth-decay sugar.
These days, the wagons are circling around sugar. And the same people who excoriate the demonization of fat in the 80′s and 90′s are perfectly willing to throw sugar under the bus. But it’s not just the white stuff under fire: fruits & fruit juices are under the gun; milk, cheese & yogurt; even vegetables are not safe from our sugar-bashing ways. There are important distinctions between added sugars and the sugars naturally present in fruits & vegetables, but these tend to get lost in the fear-mongering that passes for “debate” on this topic.
When did common sense in diet & nutrition go out the window? Since when do we have to ask if fruit is good for us or if it’s healthy to eat four fried eggs and an avocado in one sitting? Maybe it’s a function of our quick & easy access to the internet: we ask because we can. Or maybe it’s the 24-hour newsfotainment cycle that must keep churning, churning, churning away: everyone loves a good ‘breaking’ news story on the latest food that is killing us, right?
So: lest I go all Sam Kinison on y’all the next time I see a toxic-sugar-is-killing-you!!! article, I thought I would try a different approach: data. Science. Verifiable facts and peer-reviewed medical opinion. Because you shouldn’t have to take my word for it: you should be able to judge for yourselves. It doesn’t take a brain surgeon to understand basic nutrition: all it takes is a an open mind, some critical thinking skills, and a little 10th grade biology. Are you ready? Sweet.
What is sugar, anyway? Tricky question that. Most of us think of “sugar” as table or baking sugar: the refined, white crystalline stuff that we add to coffee or use to bake cookies. Crystalline sugar itself comes in many forms: white, brown, raw, powdered. A food scientist may think of “sugar” as the generalized name for sweet, short-chain, soluble carbohydrates, while a biochemist will tell you that “sugars” are mono- or disaccharides composed of carbon, oxygen and hydrogen.
The easy answer is this: all foods stuffs fall into one of three categories – fat, protein or carbohydrate – and sugar is a carbohydrate. Specifically, the term “sugar” by convention refers to simple carbohydrates (image above) - monosaccharides like glucose and fructose, or disaccharides like sucrose (table sugar) – while complex carbohydrates (image below), connected strands of many, many saccharides (polysaccharides), are called “starch” or “fiber.” But the reality is they are all made up of the same thing. Amylose, one of the main components of the starch in a Russet potato, is made up of hundreds of linked glucose molecules. Sucrose, the chemical name for common table sugar, is a disaccharide composed of one glucose and one fructose molecule, while lactose, the sugar found in milk, is a disaccharide composed of one glucose and one galactose molecule (which is, itself, simply an isomer of glucose. Confused yet?).
The important thing to remember is this: no matter what carbohydrate you eat – kale, gummy bears, Grandma’s biscuits, apple pie – digestive enzymes will work to break down any carbohydrate that is more than a single molecule. Starches, polysaccharides, table sugar, lactose: anything larger than a monosaccharide will be broken down to a monosaccharide before it is absorbed from the gut. So, in essence, whether you eat stale Cheetos, a bag full of leftover candy corns, or a spinach salad, the only carbohydrates your blood ever sees are glucose, fructose and galactose. And galactose is basically glucose doing a princess wave, so, we’ll focus on glucose & fructose for now.
|simple carbohydrate||complex carbohydrate|
|“sugar”||oligosaccharide||“starch” & “dietary fiber”|
|1 or 2 saccharides||3 – 10 saccharides||>10 saccharides|
|minor contribution to US diet
So, to recap: all sugars are carbohydrates, and all carbohydrates are made up of single (mono) or linked (di or polysaccharides) sugar molecules. This is true whether the sugar in question is spooned into your coffee, crunched in a carrot stick or wolfed down as bread & brie.
Now, before the angry hordes descend on this little blog ‘o mine, take note: I am not saying that a bag of candy corn and a spinach salad are equally nutritious. What I am saying is that after enjoying either of those treats, what will end up in your blood will be much the same thing: glucose or fructose. The total amount, the rate of absorption, and the other components that come along for the ride have as much, if not more, to do with the nutritional quality of any meal than the simplified “grams sugar” that food labels like to trumpet (or whisper).
I am also not saying that everyone should rush right out and start gorging on sugar: there are good reasons for anyone to avoid overindulging in added sugars (tooth decay among them!) and especially good reasons for people with metabolic disorders (diabetes, hypoglycemia). But the best reason to avoid sugar, in my opinion? That you feel better when you do. If so, bravo! Keep on avoiding the white stuff. To find out why your body might react differently to the sugar in a Jolly Rancher than the sugar in a carrot stick, despite the fact that your blood will see the same molecules, join me in the next installment in the Sugar series when I discuss basic carbohydrate metabolism & energy balance, a.k.a. “What happened to all that pasta alla carbonara, anyway?” Until then: science, bitches!
Want more? Read on for Part 2!