Biology 101: Understanding Refined Grains and Sweetener Differences

Sep 23 2011

Biology 101: Understanding Refined Grains and Sweetener Differences

I have a confession:

I didn’t read Michael Pollan’s In Defense of Food until last month. I’ve had it shelved on the food section of our bookcase for several years, but every time I started to pick it up, I started another book instead. I don’t think there’s a reason to read too deeply into this: I wasn’t subconsciously ranking In Defense of Food as less important than another food book! My reasoning and subsequent avoidance was that after two years of immersing myself in reading, talking, writing about, cooking, and photographing food, I’m familiar with much of Pollan’s message through Omnivore’s Dilemma and his many articles. I gravitated towards books about subjects of which I knew little to nothing, like fish (Bottomfeeder) and tomatoes (Tomatoland).

When I finally did read In Defense of Food, I flew through it in less than a week, nodding my head at things I agreed with and had witnessed in person, and underlining several passages that I wanted to learn more about.

With In Defense of Food, Pollan analyzes how our food system arrived at the place it is today and how we, as individual consumers, can start to make more informed choices about what we eat, and our subsequent health. This boils down to a diet of greens, whole unprocessed foods, and minimal meat consumption, with awareness that “you are what the animal you eat eats”.

So what were the subjects I underlined in In Defense of Food? They revolved around the discussion of processed grains and sugars and the fact that no matter what nutrients you add back into a processed food item, nutrition is not a reductive science. As Michael Pollan shares: “People don’t eat nutrients, they eat foods. And foods can behave very differently from the nutrients they contain.”

As a 2003 American Journal of Clinical Nutrition study reported, no single one of the nutrients present in whole grains can explain the benefits of whole grain foods. Isolating nutrients and putting them back into refined grains doesn’t make a refined grain the nutritional equivalent of a whole grain. Various grains and their parts act synergistically: a whole food might be more than the sum of its nutrient parts. We don’t know enough to compensate for everything that processing does to whole foods. Destroying complexity is a lot easier than creating it.

In an effort to gain an understanding of refined flours and sugars, I went down the nutrition rabbit hole, using both Marion Nestle’s always helpful articles, as well as several studies, to learn what exactly differentiates a processed grain from an unprocessed grain, and the relationship between glucose, sucrose, and fructose. If you can remember Biology class, you might already be aware of the differences between sucrose and fructose, but I only have foggy memories from 10th grade, so I sought out definitive definitions for all of these terms.

Accurate definitions are important in any situation, but I think it’s an especially good idea to have a basic understanding of refined foods, as these are terms that are frequently in the media, and can be reported in a confusing or even inaccurate fashion. Most recently, the High Fructose Corn Syrup Association has pushed to rename their product corn sugar. (11) And on the other extreme, the backlash against HFCS has led to a surge in drink companies promoting beverages made with real cane sugar, implying that these drinks are a healthy option because they’re not made with HFCS.

Flour

Flour can be refined, refined and bleached, and unrefined.

Before 1870, wheat was ground between two stone wheels. This grinding process removed the bran from the wheat kernel, but didn’t remove the nutrient rich germ. In 1870, rollers were invent, making it possible to remove the germ and grind the remaining starch and protein into a fine powder. Unfortunately this white powder is nearly nutritionally worthless. After bouts of pellagra and other deficiencies swept the public, millers began fortifying grains with B vitamins, and later, with folic acid. (1)

Refined grains:

-extend shelf life (but they’re less nutritious to us AND pests )

-remove fiber that slows the release of their sugars

-have starches that turn to glucose more quickly

-bleached flour (any flour that’s had a whitening agent applied) allows the baked good to set faster and/or rise better to rise more quickly

Because of its ability to give us a quicker hit of glucose, our bodies crave refined flour even though it offers next to nothing nutritionally. The grain has become a simple carbohydrate, which the body converts so quickly to sugar that it’s almost like eating sugar directly. (2)

Whole grain products include the bran, germ, and endosperm of the grain. The entire wheat (or other grain) is ground up. How much whole grain is in a whole grain product varies from item to item. (2)

Bottom Line:

While there may be recipes better served by using refined flours and grains (including certain kinds of baked goods), you’re doing yourself no nutritional favors by eating processed and refined grains. Seek out items that are listed as whole grain and check the finer print to see if white flour still makes the ingredient list. Experiment with whole grain cooking and baking! And if you can, stay away from the bread basket, no matter how hungry you might be while you’re waiting for dinner. If you have to use white flour to cook, definitely make sure to use unbleached (naturally whitened) flour. Flour naturally whitens due to oxidation.

Glucose, Sucrose, and Fructose, including HFCS

Sugars provide our bodies with calories but no nutrients. According to Pollan--on average, 20% of our calories now come from sugar and 40% come from carbohydrates, 9 servings of which are refined -- and this number has potentially grown in the years since his book was published. (1)

Glucose / blood sugar: Glucose is the body’s main source of energy. Most carbohydrates are broken down into glucose during digestion. If you hear the phrase (maybe even from me!) “I have low blood sugar” it means that that person’s body is craving energy and is seeking it in the quickest way possible. When the body converts food to glucose, it produces insulin that is conveyed to cells to be used as energy. (7 and 1)

Fructose / fruit sugar: Fructose is found naturally in fruit. If you’re eating fructose in its natural form, few health issues are raised because the fructose absorption is accompanied by nutrients and fiber, slowing the absorption and providing your body with a complicated bundle of nutrition. Because fructose doesn’t stimulate the release of insulin (6), the body processes fructose differently from glucose: fructose is metabolized in the liver. The liver turns the fructose first into glucose, and then, if there’s no need for more glucose, into fat. (1)

High Fructose Corn Syrup / corn sugar: HFCS is made from corn starch. Like sucrose, it’s also a mixture of glucose and fructose. In this case, the combination is not 50/50, but instead contains more fructose than glucose.

At most, HFCS’s chemical makeup should be 55% fructose (as compared to the 50% found in table sugar). (5) “Supposed to” is the key phrase, as a recent study found that some drinks tested had up to 18% more fructose than expected and that some brands of soda seemed to be made with 65% fructose, not 55%. (5)

Agave Sugar: Agave can have much higher concentrations of fructose than either sucrose or HFCS. Its labels do not give percentages so you have no way to know how much. (7) Because agave is more expensive than other sweeteners, you probably won’t use as much of it. (8)

Sucrose / table sugar: Sucrose be made from sugar cane or sugar beets. Its chemical makeup is 50% glucose and and 50% fructose, bonded together. In digestion, enzymes split the glucose and fructose apart. (7)

Any sugar other than “sugar in the raw” is refined. US labeling law does not require the origin of the sugar, whether cane or beet, to be noted on packaging (3). C & H is the only mass-market producer to do so. (4)

A study reported in the San Francisco Chronicle found that cooks and bakers dramatically preferred their baked goods (and the baking process) when made with cane sugar. Unfortunately, beet sugar is generally cheaper to produce, as it requires one less step in the refining process. As of now, beet sugar accounts for 55% of refined sugar consumed each year, and this number is growing. (4) The biggest discrepancy between beet and cane sugar seems to be with brown sugar. Brown sugar made from beets has molasses added back to the refined white sugar. With cane sugar the brown sugar may be a less-refined product as it is simply a step in the production process. (3)

Bottom Line:

Americans are drinking 50 gallons of soda every year, which adds up to 34 pounds of sugar. In addition to soda’s empty calories, high levels of fructose can have negative health effects that include insulin resistance and fat deposits in the liver. In the University of South Carolina Sugar Content Study, even Mexican coke, frequently sought out because it contains sugar and not HFCS (and beloved by hipsters everywhere), was found to contain fructose and glucose (HFCS), not sucrose. Marion Nestle had several thoughts about this finding:

the company may have deceptively used HFCS instead of sucrose
the coke may have been old and the sucrose “inverted” (split into glucose and fructose)

If HFCS contains 55% fructose, as manufacturers claim it does, that percentage is not significantly different from the 50% in table sugar. If, however, HFCS contains fluctuating amounts of fructose, the claims that HFCS and sucrose are biologically the same need to be rethought. (5)

As far as the recent debate about changing the name from HFCS to corn sugar, Nestle sums it up best:

“It is highly unlikely that public misunderstanding of nutritional biochemistry and the differential physiological effects of glucose vs. fructose will be addressed and corrected by changing the name of HFCS to corn sugar.” (10)

It’s important to keep in mind that the term “HFCS-free” has become a calorie distractor. I’m guilty in selecting drinks sweetened with “real cane sugar”, but in actuality white table sugar is not something you should seek out in your drinks. As with everything, the best way to stay healthy is through moderation and an understanding of what is in your food and how your body digests and deals with those ingredients. And in the coming months, you may be seeing HFCS less and less in drinks and even other products, as HFCS has become more expensive to make as more of it is used for ethanol. (12)

Ultimately, try to think of food as less of a thing and more of a relationship--and not just a relationship among the ingredients you’re cooking with but also the people with whom you eat.