How fake sugars sneak into foods and disrupt metabolic health
Artificial sweeteners and other sugar substitutes sweeten foods without extra calories. But studies show the ingredients can affect gut and heart health.
Making foods even sweeter
Table sugar, or sucrose, is still the dominant sweetener in the food supply, and eating a lot of ultra-processed foods with added sugar has been linked to chronic illness and obesity. The number of new food products containing sucrose has fallen by 16 percent in the last five years. Use of high-fructose corn syrup and agave syrup also have declined.
“These low-calorie sweeteners are ubiquitous in the food supply, and so people often aren’t even aware that they’re consuming them,” said Allison Sylvetsky, an associate professor in the department of exercise and nutrition sciences at George Washington University.
Many sugar substitutes are known as high-intensity sweeteners because they’re often hundreds of times sweeter than table sugar. Some are synthetic, like sucralose, aspartame, and saccharin, while others, like allulose, stevia and monk fruit extract, are referred to as “natural” because they’re derived from plants.
Popular sweeteners
compared to table sugar
Times
sweeter
Synthetic
200 to 700
Saccharin
Sucralose
600
Aspartame
200
“Natural”
Stevia
200 to 400
Monk fruit extract
100 to 250
Source: U.S. Food & Drug Administration
Popular sweeteners
compared to table sugar
Times
sweeter
Synthetic
200 to 700
Saccharin
Sucralose
600
Aspartame
200
“Natural”
Stevia
200 to 400
Monk fruit extract
100 to 250
Source: U.S. Food & Drug Administration
Popular sweeteners compared to table sugar
Times
sweeter
Synthetic
200 to 700
Saccharin
Sucralose
600
Aspartame
200
“Natural”
Stevia
200 to 400
Monk fruit extract
100 to 250
Source: U.S. Food & Drug Administration
Sugar substitutes can be found in ingredient lists on food packages, often with names that many consumers don’t recognize, like adventame, neotame and acesulfame potassium. Foods that claim “no artificial sweeteners” often are sweetened with stevia and other so-called “natural” sugar substitutes.
A variety of these sweeteners are turning up in cereals, juices and other packaged foods marketed to kids — even though public health groups have discouraged their use among children.
“When I started thirty-something years ago I never saw low-calorie sweeteners in pediatric products,” said Julie Mennella, a developmental biopsychologist who studies children’s taste preferences at the Monell Chemical Senses Center in Philadelphia. “Now, they’re everywhere.”
Sucralose and acesulfame potassium are regularly used in Greek yogurts, tortilla wraps and other foods served in school meals. Schools in some states have experimented with serving chocolate milk sweetened with a blend of sugar and monk fruit extract.
A new incentive to add fake sugar
Under a proposal from the Food and Drug Administration, companies will no longer be able to label a food “healthy” unless it adheres to strict new limits on added sugars. One way companies can adhere to the proposed rules is to replace added sugars in foods with artificial sweeteners.
“When companies reformulate their foods to contain less sugar it leads them to use more non-nutritive sweeteners,” said Jotham Suez, an assistant professor at the Johns Hopkins Bloomberg School of Public Health who studies sugar substitutes.
Studies show that when other countries, including Chile and Australia, instituted policies to reduce sugar consumption, the result was an increase in artificially sweetened foods and beverages.
How fake sugars affect your health
Scientists used to think that non-nutritive sweeteners were largely inert, activating sweet receptors on our tongues and passing through our bodies without causing metabolic changes. But questions remain about the health effects of consuming large amounts of these ingredients.
The World Health Organization cautioned people to limit their intake of sugar substitutes because of their potential for “undesirable” long-term effects, including detrimental effects on gut and metabolic health.
Robert Rankin, the executive director of the Calorie Control Council, an industry group, pushed back against claims that sugar substitutes come with health risks. “Evidence shows that low- and no- calorie sweeteners are a safe and effective alternative to added sugars and can be used as part of a balanced diet to help consumers achieve dietary goals, whether it be managing weight or diabetes, reducing the consumption of added sugars, or reducing total caloric intake,” he said.
Powerful effects on the brain
In a clinical trial published in JAMA Network Open, researchers found that drinking beverages that contained sucralose increased food cravings in women and people with obesity and led women to eat larger amounts of food at their next meals.
At the same time, research in animals suggests that sweet flavors, whether from sugar or from artificial sweeteners, can have powerful effects on the brain’s reward center. When given a choice between cocaine or water sweetened with saccharin, rats will almost always choose the artificially sweetened beverage.
Studies suggest that our taste receptors and willpower can be easily overwhelmed by intensely sweet flavors — even if those flavors come from fake sugar.
Effects on weight and cardiovascular health
Scientists say it’s hard to fully understand the health effects of all these sugar substitutes. One reason is that there are so many of them. At least six artificial sweeteners have been approved by the FDA: Saccharin, sucralose, aspartame, acesulfame potassium, neotame and advantame. Companies are also allowed to use other non-nutritive sweeteners that the agency deems “generally recognized as safe,” which means they don’t have to undergo rigorous FDA safety reviews.
Observational studies suggest that people who consume a lot of low-calorie sweeteners have higher rates of obesity and weight gain. But that may be a case of reverse causality, since people who are at risk of obesity are more likely to choose diet foods and beverages. The most rigorous clinical trials show that when people replace sugary drinks with artificially sweetened beverages like Diet Coke and Diet Pepsi it helps them avoid gaining excess weight.
For many years, artificial sweeteners were plagued by concerns that they could cause cancer, largely stemming from early research in rodents. But the American Cancer Society says that there is “no clear evidence that these sweeteners, at the levels typically consumed in human diets, cause cancer.”
They can, however, have other concerning effects. A large study published in the BMJ found that a high intake of artificial sweeteners increased the risk of cardiovascular problems such as strokes and coronary heart disease.
Another study published in Nature Medicine linked the sugar substitute erythritol to higher rates of heart attacks and strokes. The researchers found that when people consumed erythritol in amounts commonly found in processed foods it stayed in their systems for days and had the potential to promote blood clots.
The Calorie Control Council challenged the study results, saying they are “contrary to decades of scientific research.”
Detecting the hidden sugar substitutes
The American Academy of Pediatrics says the FDA should require food companies to list the amounts of any non-nutritive sweeteners on the nutrition facts panel, alongside things like fat, carbohydrates and added sugar. Some consumer groups called for new labeling rules to make it easier to know when sugar substitutes are used in packaged foods.
Some examples of foods the sugar industry called out include:
- Blueberry protein bars. Some “low sugar” protein bars claim on the label that they contain just one gram of sugar. But you’d have to flip to the ingredient list on the back to see that your bars might be sweetened with multiple sugar substitutes such as erythritol, allulose and sucralose.
- Greek yogurt. Your vanilla Greek yogurt may claim it contains no added sugar or artificial flavors. But if you check the ingredients, you might discover it’s sweetened with stevia leaf extract. Some brands of low-sugar yogurts actually have more calories than the regular version.
- Flavored oatmeal. “Lower sugar” instant oatmeal varieties claim to have as much as 35 percent less sugar than the regular version. But that’s because food makers have decreased the serving size and added monk fruit extract.
- Peach fruit cups. The label may say that your diced peaches are packed in “naturally sweetened water” with no added sugars and no artificial sweeteners or flavors. But the ingredient list for some brands indicates that they’re sweetened with stevia leaf extract.
Rankin, from the sugar-substitute industry group, said that current food labels give people sufficient information to identify products that contain both caloric sweeteners as well as sugar substitutes.
So what should you do?
Experts say it’s clear that consuming a lot of sugar is bad for your health. But Suez and others say you should be cautious about replacing sugary foods with sugar substitutes. It’s best to consume any kind of low-calorie sweetener in moderation. Pay attention to ingredient lists. Another simple measure is to reduce your intake of highly processed foods, which tend to contain a lot of sweeteners and other additives.
Do you have a question about healthy eating? Email EatingLab@washpost.com.