Not-so-sweet heart

Too much added sugar isn’t just bad for your waistline and your risk of diabetes.

“Research suggests that consumption of typical amounts of added sugar over a lifetime is increasing your risk of cardiovascular disease and cardiovascular death,” says Kimber Stanhope, a researcher at the University of California, Davis.

The case against added sugars (like high-fructose corn syrup and table sugar) has been mounting for years. For example, in 2014, researchers reported that people who consume the most added sugars are twice as likely to die of cardiovascular disease (largely heart attacks or strokes) than those who consume the least.1

And last year, Stanhope published a study that may explain why.

“We found direct evidence that added sugars increase risk factors for cardiovascular disease,” she says. The participants (aged  18 to 40) drank one of four Kool-Aid-like beverages with breakfast, lunch, and dinner for two weeks. The drinks were made with a dose of high-fructose corn syrup equal to 0,  10,  17½, or 25 percent of their daily calorie requirement.2

The results

The higher the dose, the higher the participants’ LDL (“bad”) cholesterol and post-meal triglycerides.

“I didn’t expect to see anything at 10 percent, but we did,” says Stanhope. “Even the addition of that amount of sugar​—equivalent to half a can of regular soda with each meal—was enough to raise risk factors for cardiovascular disease.”

How might sugars raise LDL and triglycerides?

It’s the fructose half of table sugar (sucrose), high-fructose corn syrup, and other added sugars that seems to cause trouble. “Fructose is nearly exclusively metabolized in the liver, so it doesn’t get to the rest of the body,” explains Stanhope. “When the liver gets overloaded, it turns some of the fructose into fat. Some of that fat ends up in the bloodstream as triglycerides, and that eventually leads to a rise in LDL cholesterol.”

“Our study found that people are sensitive even to the addition of  10 percent of their calories from sugars,” she adds. “And the more sugar you consume, the higher the risk.”

The bottom line

Women and children should limit added sugars to no more than 6 teaspoons
(100 calories’ worth) a day, as the American Heart Association
recommends .3 Men should limit themselves to 9 teaspoons­—150 calories’ worth.

1 JAMA Intern. Med. 174: 516, 2014.
2 Am. J. Clin. Nutr. 101: 1144, 2015.
3 Circulation 120: 1011, 2009.

Find this article about added sugars and heart health interesting and useful? Nutrition Action Healthletter subscribers regularly get sound, timely information about how exercise, diet, and lifestyle can affect their health. They also receive science-based advice about diet and diabetes, heart disease, cancer, osteoarthritis, and other chronic diseases; delicious recipes; and detailed analyses of the healthy and unhealthy foods in supermarkets and restaurants. If you don’t already subscribe to the world’s most popular nutrition newsletter, click here to join hundreds of thousands of fellow health-minded consumers.

5 Replies to “Not-so-sweet heart”

  1. Based on its conclusion that it is the fructose that is the primary culprit in added sugars causing a rise in LDL cholesterol, this article also should address the question: Since fructose is the primary sugar in fruit, should the consumption of fruit be reduced or eliminated to minimize as much as possible the ingestion of fructose?

    The answer is no, but it would be helpful if this article addressed this inevitable question.

  2. well written, scientifically based and to the point. I look forward to reading more articles from you Caitlin!

  3. These articles are SO helpful! Especially knowing they are backed by science. Can’t thank you enough for the work you do in the public interest.

    1. That’s true. There’s a great deal of added sugar in most processed foods, so we recommend limiting processed foods (and reading labels) as much as you can. You don’t need to avoid the naturally occurring sugars in fruit and dairy, though.

Leave a Reply

Your email address will not be published. Required fields are marked *