The JAMA study authors analyzed seven years of data from the National Health and Nutrition Examination Survey, administered annually by the Centers for Disease Control and Prevention. The data tracks such things as diet, body mass index, cholesterol level, and blood pressure, as well as behaviors like smoking, exercise, and alcohol consumption. After excluding people with diabetes, those who were excessively overweight, and those with high cholesterol, the researchers found that adults consumed an average of 21.4 teaspoons of added sugar a day, that is, sugar that doesn't exist naturally in foods such as milk or fruit. That amount equaled 16 percent of their total caloric intake, and for about 16 percent of the sample, sugar comprised more than 25 percent of total calories. (Current recommended daily guidelines are 5 teaspoons for women, 9 teaspoons for men, and 5 percent or less of daily calories.)
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Even more alarmingly, the study showed that as the number of added-sugar calories increased, the levels of good cholesterol (HDL) went down, and bad cholesterol (LDL) and triglycerides (another blood fat) went up. These strong associations held true even after the researchers controlled for other risk factors for high cholesterol and heart disease.
How and why added sugars increase cholesterol level isn't fully understood, say the authors, but one theory is they cause your liver to secrete more bad LDL cholesterol and interfere with the body's ability get rid of it. "Taking a broader view, we know that a diet high in added sugars is a marker for a poor-quality diet in general," says Rachel K. Johnson, PhD, MPH, RD, associate provost and professor of nutrition at the University of Vermont in Burlington. Johnson authored the American Heart Association's (AHA's) recommendations for sugar intake because, she says, there's already a large body of evidence suggesting that added sugar is bad for the heart.
Even knowing that added sugars pose a significant health risk, you may still have a tough time modifying your diet to reduce that added sugar. "One problem is that the Food and Drug Administration [FDA] doesn't require added sugars to be called out on the Nutrition Facts panel," Johnson says. The AHA has petitioned the agency to do this, but considering that it took 10 years of petitioning to get the FDA to list trans fats, the AHA has turned more of its attention to getting food companies to lay off the sugary additives. "We're trying to work directly with the food industry to modify their products," says Johnson. "But getting added sugar onto food labels would be huge, and so helpful for consumers."
The easiest way to avoid added sugars is to eat more whole foods and less processed foods. Here are some other strategies you might try:
• Know what "sugar" means. Healthy foods, such as whole-grain bread, fruit, and low-fat dairy products, have naturally occurring sugars. So Nutrition Facts labels on those products will indicate that they contain sugar, which is fine. But to drill down to the difference between added sugar and naturally occurring sugar, look at the ingredients list. The following are sugars that may be added to products. Some are natural, such as honey, but they still count as added sugars if they're in the ingredients list: glucose, sucrose, lactose, honey, maltose, dextrose, fructose, molasses, corn syrup, high-fructose corn syrup, maple syrup, corn sweetener, juice concentrate, natural sweeteners, refined sugar, turbinado sugar, confectioner’s (powdered) sugar.
• Use added sugar to flavor whole foods. "We're not advising people to eliminate added sugars entirely from their diets, just to use them with discretion," says Johnson. She suggests satisfying your sweet tooth by using natural sugars to enhance the flavor of already nutritional foods. For example, if you enjoy strawberry yogurt, buy plain yogurt and add real strawberries with a little honey. Or bypass that packet of instant maple brown sugar oatmeal, and replace it with a serving of quick-serve oats, adding a touch of maple syrup or brown sugar yourself.
• Know your sugar target. Help keep your cholesterol levels under control by following the AHA’s recommended sugar guidelines:
• for adult women: 5 teaspoons (20 grams) a day
• for adult men: 9 teaspoons (36 grams) a day
• for children: 3 teaspoons (12 grams) a day.
Added sugars should comprise no more than 5 percent of your total daily caloric intake. For some examples of how much added sugar is present in various processed foods, read our story "Report Provides New Sugar Recommendations for Adults."