By Rita Rubin
WebMD Health News
Reviewed by Hansa D. Bhargava, MD
Dec. 24, 2014 -- America's sweet tooth is coming under fire.
Faced with mounting evidence about sugar's harms, the 2015 Dietary Guidelines Advisory Committee this month recommended that people in the U.S. limit added sugars to a maximum of 10% of their total daily calories.
The recommendation -- from the group responsible for MyPlate -- will be part of a scientific report submitted in early 2015 to the secretaries of the Departments of Health and Human Services and Agriculture, who will use it to update the official Dietary Guidelines for Americans.
On average, Americans get about 16% of their daily calories from added sugars, according to the FDA. Earlier this year, the agency proposed changing the Nutrition Facts Label to tease out added sugars from the total sugar content in foods and drinks.
On a 2,000-calorie-a-day diet, 10% of calories from added sugar represents an amount equal to a dozen teaspoons right out of the sugar bowl -- not that people are dumping that much sugar on top of their breakfast cereal or into their lattes.
"Just as most dietary sodium does not come from the salt shaker, most dietary sugar does not come from the sugar bowl," writes James DiNicolantonio, PharmD, from the preventive cardiology department at Saint Luke's Mid America Heart Institute in Kansas City, MO. He co-wrote a review article in Open Heart, an open-access online journal from BMJ and the British Cardiovascular Society.
Naturally occurring sugars in whole foods such as fruit are of no concern, DiNicolantonio writes, but "added sugars probably matter more than dietary sodium for hypertension, and fructose in particular may uniquely increase cardiovascular [heart and blood vessel] risk." Dietary guidelines should shift focus away from salt and more toward added sugars, he writes.
A typical 20-ounce bottle of sugar-sweetened soda has 15-18 teaspoons' worth of sugar, although you might not see that word on the label. Other names for added sugars include high-fructose corn syrup, fruit juice concentrate, molasses, honey, and sucrose.
Even foods that you wouldn't think of as sweet have added sugar, often in the form of high-fructose corn syrup. In the U.S., this ingredient "is in a lot more foods than you realize," such as ketchup, mustard, and bread, says Jill Kanaley, PhD. She's a professor of nutrition and exercise physiology at the University of Missouri. High-fructose corn syrup is a preservative, giving packaged foods a longer shelf life, and it plays a role in color and texture, Kanaley says.
Why should Americans cut back on sweetened foods and drinks? The Dietary Guidelines Advisory Committee's working group on added sugars says there's strong scientific evidence that added sugars, especially sugar-sweetened drinks, raise the risks of excess weight and obesity, as well as type 2 diabetes. The group also found "moderate" evidence connecting added sugars to high blood pressure, heart disease, and stroke, along with tooth decay.
The American Heart Association recommends even stricter limits on added sugars -- no more than 150 calories a day for men, 100 for women-- than the dietary guidelines working group. The main reason for restricting added sugars is because they're a major contributor to obesity, according to the group's scientific statement on dietary sugars and heart health.
"Soda and other sugar-sweetened beverages are unlike most things in the diet in that they provide nothing of value, but are major drivers of diabetes, heart disease, obesity, and other health problems," Michael Jacobson, PhD, said in a statement issued after the last meeting of the 2015 Dietary Guidelines Advisory Committee. Jacobson is the director of the Center for Science in the Public Interest (CSPI). "It's encouraging to see the Dietary Guidelines Advisory Committee use such strong language recommending reduced consumption of those beverages."
The scientific community is beginning to realize that when it comes to sugars, all calories are not created equal, he says. Studies have shown that different sugars have different effects on metabolism.
Simply switching from sugar-sweetened soft drinks to water could make a big difference, he says. "Soda's not just calories. It's calories in liquid form. The body doesn't seem to compensate as well."
In other words, if you scarf down a late-afternoon snack of a cookie with 150 calories' worth of added sugar, chances are you might not eat quite as much at dinner. But a glass of soda that packs 150 calories of added sugar won't stick to your ribs the same way as that cookie, so you won't eat less to compensate for those empty calories, Jacobson says.
"There's so much evidence on soda, because it's kind of the easiest thing to test," he says. "It's pure sugar water, and it's very widely consumed." In February 2013, CSPI petitioned the Food and Drug Administration to determine safe limits on sweeteners used in soft drinks.
The Obesity Link
The effect of added sugars on health is a subject of ongoing debate, though. Just a week before the Dietary Guidelines Advisory Committee met in December, speakers at a conference entitled "Advances & Controversies in Clinical Nutrition," sponsored by the American Society for Nutrition and the Tufts University School of Medicine, downplayed sugar as a major cause of obesity.
James Rippe, MD, a cardiologist who helped organize and spoke on the panel about sugar and health, acknowledged that "it's not an unreasonable thing to limit sugar," because it can cause weight gain.
But added sugars are the least of the obesity problem, Rippe said. From 1970 to 2010, he said, the average number of calories Americans took in daily rose by 474, but only 39 of those extra calories come from any type of added sugar.
But "if you try to say something positive about sugars, God help you, the mommy bloggers will kill you," he said.
Rippe is a professor of biomedical sciences at the University of Central Florida, and he's the founder of the Rippe Lifestyle Institute in Celebration, FL. The institute lists as partners on its web site several companies that make sugar-sweetened foods or drinks, including PepsiCo North America. His research has been supported in part by the Corn Refiners Association, whose members make sweeteners such as high-fructose corn syrup.
Fructose is the sugar in fruit, vegetables, and honey. Although population-based research has linked the obesity epidemic to eating and drinking more high-fructose corn syrup, a link doesn't prove cause and effect, Rippe says.
"I think you could point to a lot of things" that occurred at the same time that use of high-fructose corn syrup and obesity trended upward in the U.S., Kanaley says. More reliance on technology and less exercise could be one explanation for the obesity epidemic, she says.
But, Jacobson points out, obesity rates have nearly plateaued at the same time that the total amount of sales of caloric sweeteners has leveled off.
Even so, he says, "too many people are adding a ton of calories from soda. It is the only food or beverage that's been demonstrated in clinical studies to cause weight gain."
SOURCES: DiNicolantonio, J.J. Open Heart, published online Dec. 11, 2014. Johnson, R.K. Circulation, Sept. 15, 2009. Health.gov: "Dietary Guidelines." Michael Jacobson, PhD, executive director of the Center for Science in the Public Interest. James Rippe, MD, professor of biomedical sciences, University of Central Florida. Jill Kanaley, PhD, professor of nutrition and exercise physiology at the University of Missouri. American Heart Association: "Sugar 101." U.S. Department of Agriculture: "Sugar and Sweeteners Yearbook Tables."
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