UW News

January 22, 2024

Q&A: UW expert on the rise and risks of artificial sweeteners

UW News

Eight white sugar cubes set against a black background.

Credit: Saramukitza via Pixabay

Call it the sweetness paradox. In grocery stores across America, foods that were once saturated with sugar now contain none — yet they taste just as sweet.  

The secret is an assortment of additives that replicate sugar’s sweetness, but not its calorie count. Broadly classified as non-sugar sweeteners (NSS), these additives are creeping into everything from diet sodas (aspartame) to no-sugar-added fruit cups (sorbitol, sucralose, acesulfame potassium).

The rise of NSS has made it easier for conscious consumers to reduce their sugar intake, but these products may present their own health risks. In an article published Jan. 22 in the journal JAMA Pediatrics, Dr. James Krieger, a UW clinical professor of health systems and population health and executive director of Healthy Food America, and a team of co-authors argue for better and more comprehensive data on the proliferation and possible health effects of non-sugar sweeteners. They also call for reducing children’s exposure to NSS by restricting their use in kids’ food and beverages.

“The growing presence of (non-sugar sweeteners) in the food supply, combined with mounting concerns about their use… suggest that caution in adding them to foods and beverages is needed,” Krieger and his colleagues wrote. 

UW News sat down with Krieger to discuss what we know — and what we need to know — about these ever-present products. 

NSS have been getting a lot of attention lately, from their possible health effects to their impact on our overall diets despite having been used for decades. What’s the debate surrounding these products, and why are they drawing so much attention now? 

James Krieger: There’s been a longstanding controversy over the safety and efficacy of non-sugar sweetened products. The debate has just been lifted up recently because of a couple of things. Last year, the World Health Organization recommended that NSS not be used to achieve weight control or reduce the risk of non-communicable diseases, which means chronic diseases like diabetes or heart disease. That created quite a stir. The food industry, particularly those who rely on these products, reacted negatively to the WHO report, while many public health officials and advocates said this is a great and long- overdue statement. 

There’s also growing use of these products in the food system, particularly as more consumers are looking for and demanding products with less sugar in them. This is because there is widespread awareness of the negative health consequences of too much sugar consumption. Industry is substituting NSS for sugar. They don’t want to change the overall sweetness of their product, because they know really well that sweet foods attract consumers. Instead, they’re maintaining sweetness by substituting NSS for sugar. 

Just how much of these products is the average American eating?  

JK: There’s not great data on consumption of NSS, and that’s a real gap in the knowledge right now. There’s better evidence on consumption of sugars, and that is going down.  

The challenge is that the food industry is not very transparent about how much non-sugar sweeteners are in their products. They have to list sweeteners on the ingredients list, but they don’t have to list the amount. So we know in more of a binary yes/no fashion, are people eating products with non-sugar sweeteners? And the trend line of that looks like it’s going up. For example, a recent report from the Environmental Working Group found that the number of food and beverage products containing non-sugar sweeteners increased three- to five-fold between 2013 and 2022. 

We need a lot more research and better data to know what the exposures to these products are. We don’t really know how much people are consuming right now. 

On a quick trip through the grocery store, one might come across a dozen different non-sugar sweeteners. There’s the classics, aspartame and sucralose, the sugar alcohols like erythritol and xylitol, and the “natural” NSS like stevia and monk fruit extract. Do different sweeteners interact with our bodies differently? Do some carry greater potential health risks than others?   

JK: It’s not clear. Most of the studies, particularly the long-term studies, have looked at these products as a group. But each one has a distinct pharmacologic and toxicologic profile. Some of the older NSS have been directly assessed by the FDA, but those assessments are very dated now. The way the newer NSS get into the food supply now is that industry just needs to send in a statement to the FDA saying that, in their estimation, these are safe.  

Now that said, there are some specifics. Some credible researchers and agencies within the WHO have raised concerns that aspartame may be linked to cancer. Others disagree. It’s clear that saccharine is probably a carcinogen, and it’s not used much now. A recent study that came out on erythritol looked at its association with cardiovascular disease, that is death or non-fatal heart attacks or strokes, and found they were increased. The researchers found a possible mechanism for that, linking non-sugar sweeteners to platelet clumping and blood clotting in vitro, which could explain that link, because these can block blood flow and cause heart attacks and strokes. So there’s a plausible mechanism that it could do that. 

My guess is that it’s probably going to be a class effect — they’ll all have kind of the same effect. And the reason I suspect that is because the common mechanism they all work by is they all bind to sweet receptors, and those aren’t just in your mouth, they’re also in organs and blood vessels, everywhere in the body. All of these products bind to those sweet receptors, no matter where they are. And then they might have effects ranging from insulin sensitivity, glucose metabolism, to vascular reactivity, platelet activation and so on.

There’s really pretty good evidence from long-term epidemiological diet studies that link exposure to non-sugar sweeteners to Type II diabetes, to weight gain, to heart disease. Those certainly are three big public health problems right now. That’s what has gotten me concerned about these and why I think we need to be taking a more active, aggressive approach toward limiting people’s exposure to them. 

You write in the article that it’s especially important to understand kids’ exposure to non-sugar sweeteners. Why is that?  

JK: In general, for any kind of environmental exposure, kids are more vulnerable because they’re going through these developmental windows when their bodies are more sensitive to the effects. Exposure early in life, can actually set up lifelong metabolic and physiological changes. So avoiding early exposure to substances associated with unhealthy biological processes is a really good opportunity to set kids on a trajectory to a healthy life as opposed to problems.  

Also, taste preferences get set early in life. There’s evidence that kids who are exposed to more sweetness will develop a lifelong preference for sweetness, and that sets them up to either consume more sugar or non-sugar sweeteners. And children don’t make choices for themselves. They’re more vulnerable, so we have to do more to protect them from any kind of thing that’s going to jeopardize their health. 

That leads me to another thing that’s a little scary. The USDA released preliminary guidelines about the amount of added sugar that can be served in school foods and meals. The guidelines say that by 2027, no more than 10% of the calories in school food can come from added sugars, which is consistent with the US dietary guidelines. That’s great, but then I worry that the food industry will put more NSS in the foods available at schools, and kids’ exposure will go up.  

You highlight other countries, most notably Chile, that require food manufacturers to be transparent about the type and amount of NSS in their products. Do you see that as an effective strategy in the U.S.? 

JK: Chile is one of the few countries that requires the amount of non-sugar sweetener to be put on labels of their food products. I think that’s a great idea, and I would love to see that happen in the U.S. 

Another approach, short of putting the actual quantitative amounts on nutrition labels, is putting labels indicating the presence of NSS on the front of packages, which is what Mexico, Colombia and Argentina have done. Many countries, predominantly in Latin America, have put front-of-package labels warning about added sugars, salt and saturated fat, which are three ingredients of public health concern. Mexico, Colombia and Argentina have added a fourth, warning that the products contain these non-sugar sweeteners and that children should avoid them. That’s probably not going to happen in the U.S. anytime soon given industry opposition and slow action by the FDA. 

There’s more potential for either FDA or USDA to require more transparency by the food industry. I could see them saying that manufacturers must disclose how much and what types of non-sugar sweeteners are in their products to a database that could be made available to researchers. It could also help if federal agencies or nutrition groups and nonprofits take this data and package it in a way to make it accessible to consumers who want to know how much of this stuff is in there. It could increase the public’s ability to access that information, and those who are really motivated might make choices about what to buy or not buy. 

And finally, let’s protect children. There’s no place for NSS in foods commonly consumed by or marketed to kids. Until we have reliable data that NSS are safe for children, let’s do all we can to make sure they do not consume them. 

For more information, contact Krieger at jwkrieg@uw.edu.