Sugar gets a bad rap. Tooth decay, insulin resistance, inflammation and weight gain can all be laid at sugar’s feet. For most humans, our sweet tooth starts when we're babies so sugary food and drinks are hard to resist.
So, why not use artificial sweeteners? Also called non-nutritive sweeteners (NNS), artificial sweeteners are everywhere. They’re commonly used in coffee and tea. They're also found in everything from bread, toothpaste, medicines, and even e-cigarettes. But are they safe?
The U.S. Food and Drug Administration (FDA) has approved five artificial sweeteners: saccharin (Sweet'N Low), acesulfame (Sunnett, Sweet One), aspartame (NutraSweet, Equal), neotame, and sucralose (Splenda). The FDA also approved just one natural low-calorie sweetener (Stevia). However, there hasn’t been a lot of research about the effects of these sweeteners and their impact on the human body long term.
"[With] the ideal advice for an acceptable intake a day, the only thing that makes that really difficult is that we don't know how many grams of sweeteners are in each product," notes Dr. Stephanie Olivier-Van Stichelen, assistant professor in the department of biochemistry at the Medical College of Wisconsin.
While artificial sweeteners may satisfy the sweet receptors all over our body (not just on the tongue), the difference is how our bodies process it, according to Olivier-Van Stichelen.
"The difference is that it will maybe not trigger as far as the metabolic response that a sugar could do," she explains. "Most of the sweeteners are not metabolized, so it means they will never break down in the body and they will just stick around."
Olivier-Van Stichelen collaborated on a recent study that looks at the effects of exposure to artificial sweeteners on pregnant and lactating mice. She notes that NNS consumption has been linked to metabolic dysfunction and changing one's gut microbiome. But not much study has looked into early life exposure, such as through breast milk.
"What we notice is that those [baby] mice have a lot of markers for detoxification problems, so they seem to have problems detoxifying a product," explains Olivier-Van Stichelen. "And then we also noticed that their microbiome was changing more than anything that's been shown in adult sweeteners treatment — that was just really surprising."

She says the study reinforces an emerging consensus by scientists: artificial sweeteners may be safe if used in moderation by adults, but they shouldn’t be treated as a magical substitution for sugar.
"I cannot say I will say it's a good or bad choice to use sweeteners or sugar. I think everything is to be used in moderation."
"I cannot say I will say it's a good or bad choice to use sweeteners or sugar. I think everything is to be used in moderation," she notes. "I think most people are conscious that this is something artificial. They may want to use it or not use it, and that's their personal choice. I just think they need to be aware of what's been demonstrated on it and what we think it's doing or not doing, or is it safe at that level."
While she admits that having NNS is a "nice alternative," there still needs to be more study done in this field. To do that, Olivier-Van Stichelen established her lab at the Medical College of Wisconsin to continue the work of researching the crossroad of sweeteners, pregnancy, development and metabolism.
"This is clearly just a discovery study that we didn't know it was going to be that different. There's not enough human clinical trial on this," says Olivier-Van Stichelen.
In the meantime, treat artificial sweeteners as you would with sugar — in moderation.