Pregnancy and the Battle of the Sugars

Pregnancy sugar

Eating healthy is vital throughout your life, but especially during pregnancy. That’s because your children’s future health is affected in the womb, due to epigenetics, which means phenomena that affect how genes function without changing their actual sequence (see more about it here). That diet can have a major impact on whether certain genes turn on or off is crystal clear, but things get trickier when it comes to deciding which foods are good and which are bad, and surfing the web can give you a severe case of nutrition confusion.

That’s particularly true when it comes to high fructose corn syrup (HFCS), which is used, especially in liquid products like soda and juice, because it is much easier to maintain in liquid form compared with table sugar, sucrose, derived from cane or beet sources. Food manufacturers like HFCS, because it is cheap and easy to maintain as liquid. This means they get a lot of sweet bang for the buck, but walking the supermarket aisles you’ll find many products with labels boasting “no HFCS”. That should be good thing, but often such foods have been sweetened instead with cane sugar. Sometimes there’s even a label, not merely admitting this, but proudly calling this added sugar ‘natural’, ‘organic’, ‘non-GMO’, implying that it makes the processed food healthier than its HFCS equivalent.

It’s smoke and mirrors, a marketing ploy, for a couple of reasons. First, the term ‘natural’ is meaningless, while classification of foods as ‘organic and ‘non-GMO’ has no correlation with a food’s nutritional value. These classifications are promoted by parties that oppose industrial agriculture and, ironically, that work in concert with the multi-billion dollar organic supermarket industry to create the impression of a health benefit.

Second, that cane sugar-enhanced juice or breakfast bar is healthier, only if the amount of sugar is less per serving compared with the HFCS product. Snacks sweetened with cane sugar are frequently very sugary, and therefore can promote gestational diabetes, if you eat a lot of them. The only label that should concern you is the Nutritional Facts Label, which usually looks something like this, and always tells you the number of grams of sugar per serving.

The motivation for HFCS in food comes down to money interests pushed by the corn industry, but the cane sugar industry and the organic food supermarket chains also want money. Their argument is that HFCS is high in fructose, which is worse than other sugars, because it does not stimulate your pancreas to secrete insulin, and so the fructose all goes to your liver, where it causes a host of diseases, especially obesity, diabetes, and metabolic syndrome. That’s all true, but it’s very deceptive and a look at the chemical structures of different sugars will show you just why.

A molecule of glucose (blood sugar) looks a lot like a molecule of fructose, but with slight differences in how the atoms of carbon, hydrogen, and oxygen are arranged. That difference is why fructose does not stimulate insulin secretion and why it all goes to the liver, but the picture also shows you that sucrose contains fructose. A sucrose molecule is made of a glucose molecule and a fructose molecule bound together. When sucrose enters your mouth, an enzyme in your saliva begins splitting it into glucose and fructose. There is more of that enzyme in the small intestine, so basically when you eat sucrose you’re getting 50 percent glucose and 50 percent fructose entering your bloodstream. How does this compare with HFCS?

The answer depends, because there are different types of HFCS, each with a specific percentage of fructose. The type used most frequently in processed foods is called HFCS-42, which has its name because 42 percent of its sugar is fructose. That’s actually better than the 50/50 ratio of sucrose, but there is also HFCS-55, meaning 55 percent fructose, and that’s used mostly in sodas. There is an HFCS-90, which is really high in fructose, but HFCS-90 is used mainly to mix with HFCS-42 to create HFCS-55.

Another point to keep in mind is that a lot of fruits and their juices –including many that are promoted as natural, organic, or healthy— have very high fructose content. Apples, pears, grapes, mangos, and watermelon are good examples, but you rarely hear of people avoiding these fruits, or cane sugar, with the same fear that they attached to HFCS.

What this all means is that you should be less concerned with the type of sugar that you consume than with the amount. Keep sugar intake as low as you can, focus on the Nutritional Facts Label on the back of the box, and when you do see a marketing ploy on the front of the box, be vigilant. The product is probably not as healthy as the company wants you to think.

David Warmflash
Dr. David Warmflash is a science communicator and physician with a research background in astrobiology and space medicine. He has completed research fellowships at NASA Johnson Space Center, the University of Pennsylvania, and Brandeis University. Since 2002, he has been collaborating with The Planetary Society on experiments helping us to understand the effects of deep space radiation on life forms, and since 2011 has worked nearly full time in medical writing and science journalism. His focus area includes the emergence of new biotechnologies and their impact on biomedicine, public health, and society.

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