High fructose corn syrup, other sweeteners may play a role in overeating
In the mercurial and confusing world of what’s good-for-you, bad-for-you, the finger-pointing has turned increasingly to high fructose corn syrup. Yet another salvo came this month.
Added sugars are found in processed foods to increase their sweet taste, make them more shelf stable and help baked goods brown and crust. These sweeteners also add calories to the diet but provide no other nutrition, such as vitamins or fibers.
The Nutrition Facts label lists the grams of sugar per serving of food. However, it does not distinguish between added sugars and naturally occuring sugars. It is the added sugars that should be avoided. To determine if the grams of sugar listed are added sugars, read the ingredients list and avoid foods that contain any of these words:
Sugar, aka table sugar, granulated sugar, white sugar, cane sugar, beet sugar, sucrose
High fructose corn syrup
Brown sugar, aka light brown sugar, dark brown sugar
Molasses or blackstrap molasses
Maple syrup or maple sugar
Powdered sugar or confectioners’ sugar, aka icing sugar
Raw sugar, aka natural brown, demerara, turbinado, muscavado or “sugar in the raw”
Glucose, aka D-glucose, dextrose, corn sugar
High maltose corn syrup
Agave nectar or syrup
Fruit juice concentrate
Fructose, aka levulose, fruit sugar
Barley malt syrup
Brown rice syrup or rice syrup
Sucanat, aka whole cane sugar, organic sugar
Splenda Sugar Blend and Splenda Brown Sugar Blend
Debbie Petitpain, MUSC Bariatric Surgery Program
But local nutrition experts say the picture is bigger than zeroing in on a single offender or “bad” guy. There’s a whole gang of added sweeteners to contend with, many of them with aliases that aren’t well recognized.
Reading food labels for added sugars can be tricky business because the Nutrition Facts information lists only “sugars,” which includes both those naturally present and those added.
In this example, the 11g of sugar listed on the container of yogurt is from the naturally occurring sugar from the milk to make the yogurt, plus added sugar from the fructose listed among the ingredients. It’s unclear how many grams come from each source.
‘Organic’ and ‘Natural’
“Organic” food defines how a food is produced and is a U.S. Department of Agriculture certification. It does not indicate that food is “healthy” or free of added sugars.
“Natural” is not government controled but applies broadly to foods that are minimally processed and free of synthetic preservatives; artificial sweeteners, colors, flavors and other artificial additives; growth hormones; antibiotics; hydrogenated oils; stabilizers; and emulsifiers. “Natural” does not exclude added sugars, either.
In fact, foods labeled “natural” will not contain artificial sweeteners and may be more likely to be sweetened with an added sugar.
Debbie Petitpain, Medical University of South Carolina Bariatric Surgery Program
Hidden high fructose?
Sodas are a well-known source of high fructose corn syrup, but it can be found in many other foods, some surprising:
Fruit juices, juice cocktails.
Candy and candy bars.
Condiments such as ketchup.
Sauces such as spaghetti.
Breads and baked goods.
“It’s sort of splitting hairs,” says Dr. Ann Kulze of Mount Pleasant, a physician, motivational speaker and best-selling author of wellness and nutrition books. “The obesity epidemic is being driven by the out-of-control consumption of sugary foods and beverages” overall, she says, with sugary drinks at the head of the pack.
In the latest report, a study published in the Journal of the American Medical Association found that the brain doesn’t register the feeling of being full when fructose is consumed as it does compared to simple glucose. While the research does not prove that fructose or high fructose corn syrup, often added to processed foods and beverages, can cause obesity, some say it adds to the evidence that fructose may play a role in overeating.
Under the microscope
Fueled by a number of research studies, fructose and high fructose corn syrup have become a favorite target in the debate over the supersizing of American waistlines. One of the early alarms was a 2004 article in the American Journal of Clinical Nutrition that suggested the rise in obesity rates was linked to increased consumption of high fructose corn syrup in beverages.
Among later studies, Princeton University researchers revealed in 2010 that rats with access to high fructose corn syrup gained more weight than those with access to table sugar, even when their caloric intake was equal. In the long run, long-term consumption of high fructose corn syrup also led to abnormal increases in body fat, especially in the abdomen.
And there does appear to be a trail: Since the sweetener was introduced in the early 1970s, U.S. obesity rates have ballooned, from about 15 percent of the population then to about a third today.
This fall, a study out of the University of Southern California found that type 2 diabetes occurred 20 percent more often in countries where high fructose corn syrup was a common ingredient in the food. The United States has the highest consumption in the world, a per-capita rate of 55 pounds per year.
Nevertheless, there are plenty of skeptics of the research and those who dispute the data outright.
Among them is the Corn Refiners Association, which says U.S. consumption of high fructose corn syrup in recent years actually has been dropping while obesity and diabetes rates continue to rise.
Five years ago, the American Medical Association came down on the Corn Refiners side, saying it “appears unlikely that HFCS contributes more to obesity or other conditions than sucrose.” They did call for more independent research at the same time.
The U.S. Food and Drug Administration also classifies high fructose corn syrup as safe for use.
Sweeter and cheaper
High fructose corn syrup was a welcome new product in the food industry when it came into mass production in the 1970s. Bolstered by U.S. corn subsidies, it was sweeter and cheaper than using cane sugar, and soon was adopted by food and beverage makers, especially for soft drinks, fruit drinks and in baked goods.
But how was it different?
Two simple molecules, glucose and fructose, form the compound sucrose — our table sugar, which is refined from sugarcane or sugar beets. Sucrose is equal parts glucose and fructose, a 50-50 split.
Both glucose and fructose are naturally present in honey, fruits and vegetables.
Glucose, also known as dextrose, is the body’s main source of energy. During digestion, carbohydrates are broken down into glucose, which is absorbed in the bloodstream. Fructose, on the other hand, goes directly to the liver, the only way it can be broken down.
High fructose corn syrup is produced by adding enzymes to corn syrup, which converts some of its glucose into the sweeter fructose, resulting in a ratio of 55 percent fructose, 45 percent glucose.
‘Like foreign currency’
“We’ve known for a long time it (fructose) is a very unique molecule metabolically,” Kulze says. “Unlike the simple sugar glucose, which is the universal fuel for all of our cells, no cells can recognize fructose. It’s like foreign currency.”
When fructose is consumed, no appetite-quieting hormones are released like what happens with glucose, Kulze explains.
“When you consume glucose, your insulin goes up, and insulin has an impact on leptin, which tells your brain appetite sensors to quiet down, you’re not hungry. … But when you take in fructose, it goes under the radar of the body’s normal appetite-suppressive mechanism.”
But the bearer of that fructose is the more critical factor, says Kulze and Debbie Petitpain, a registered dietitian who works with MUSC’s weight-loss surgery program.
That’s because nutritionists frown on any “naked” sweetener, meaning no fiber present, that makes fructose flood into the system.
Eating an apple, which naturally contains fructose, is not the same as drinking apple juice or a soda, “where you are getting a huge load of fructose that’s rapidly absorbable because it’s not bound up in fiber,” Kulze says.
“If you eat an apple, it’s so much more complex,” Petitpain says. “Yes, it has fructose in it, but it’s got fiber, it’s got water, and you have to chew it and break down the cells to release the fructose, and we know that helps provide that sense of fullness. You can slam down the same number of calories in an apple juice in one sip and it does not register as providing any sense of fullness to the body, even though it’s the exact same amount of nutrition.”
Moreover, rapidly absorbed fructose signals the liver to start making fat in the form of triglycerides, “one of those cholesterol markers that your cardiologist would measure,” Petitpain says.
‘All the same thing’
Still, high fructose corn syrup shouldn’t take all the heat, both women say. Added sugars of all kinds pose risks for obesity and other health problems.
“Fructose is in all sugars, that’s something we need to get people straight about,” Kulze says. “All sugars, despite their names, and there are 16 or 17 different aliases of sugar, everything from high fructose corn syrup to table sugar to fruit juice concentrate to maple syrup to molasses … they are all the same thing.”
Kulze agrees to a point that high fructose corn syrup has been unduly maligned. “It’s sort of splitting hairs,” she says.
She endorses the guidelines of the American Heart Association, which came out with its own recommendations in 2009. The AHA urges limiting calories from added sugars to no more than 100 calories per day for American women, or about 6 teaspoons of sugar. For men, it’s 150 calories per day, or about 9 teaspoons. The association does not single out any particular type of sugar.
What’s a consumer to do?
For starters, eat more unprocessed foods and limit sugary drinks, which expands way beyond soda these days, Petitpain says.
For example, “Your fruit juices, even your 100 percent fruit juices; your sports drinks, which are marketed heavily toward children; energy drinks; teas and even protein shakes that have a lot of fruit in them.”
Read labels wisely, Petitpain urges. Grams of sugar listed on the nutrition facts label don’t distinguish between natural and added sugars. So the public must look for red flags in the ingredients list, words that describe sugar: corn syrup, molasses, honey; and the more obscure, such as brown rice syrup and crystalline fructose.
Be careful of less obvious products that can contain added sugars, including cereal, bread, nutrition bars, yogurt, salad dressings, and condiments such as ketchup and mayonnaise.
“To me the big one is the agave nectar,” Petitpain says. “It’s really taken off in the healthy market as an alternative sugar, but there have been studies done, that it’s such an intense fructose load that it can really raise your levels of free fatty acids and triglycerides in the blood. At the end of day, it’s extra calories. And who can really afford that?”