It seems impossible to make it through this post-holiday season without everyone and their cousin offering conflicting advice about what to eat, how little, and how often. Dieters looking to cut down on fat intake are led towards foods with bolded Low Fat or Fat-Free labels. Many of these products, however, substitute refined sugars for natural fats. Others opt for increasingly popular sugar alternatives and artificial sweeteners. Last week, we talked about how the NIH investigated western “High-Fat Diets,” leading to the conclusion that processed sugar may negatively impact our intestinal microbiome. This week, we turn our attention to sugar-free alternatives.
Sugar-free sweeteners go beyond the colorful packets from the condiment caddies at family-style restaurants. MayoClinic outlines the most common sugar substitutes, including frequent fliers like saccharin (Sweet’ N Low), sucralose (Splenda), and aspartame (Equal). Xylitol and sorbitol are sugar alcohols used frequently in “Sugar-Free” products. The FDA doesn’t consider sugar alcohol a food additive, so companies may voluntarily list them among their ingredients but do not have to. If you’re familiar with the infamous Sugar-Free Gummi Bear Amazon Reviews (it’s worth a Google), the internet has thoroughly documented the stomach problems that can come with consuming too much sugar alcohol.
So what exactly is the effect of artificial sweeteners on our gut health? The answer is we don’t know yet. In one study published in the International Journal of Molecular Science, researchers used bacteria species E. coli and E. faecalis to study the effect of saccharin, sucralose, and aspartame on gut bacteria. E. coli and E. faecalis are both easy to work with in a laboratory and regularly colonize the human gut from birth. They found that the artificial sweeteners made the bacteria more pathogenic, meaning they more easily invaded and killed their target human gut cells. Outside of the lab, our microbiome is full of a diverse ecosystem of microorganisms that interact with each other to create our intestinal environment. So the effect of sugar alternatives on E. coli and E. faecalis is only one pixel in the larger picture of our health.
A different study published last year sought to define Stevia’s potential pros and cons, another popular sweetener derived from a South American herb. The results across fourteen studies were inconclusive. Sugar alcohols have similarly conflicting results. One study found the microbiome significantly altered by sorbitol. In contrast, another study found that xylitol had little to no impact.
Many of us seek out Diet and Sugar-Free products, but what about the sources of sugar substitutes we aren’t aware of? For example, Yoplait light yogurt boasts only 1 gram of added sugar, while the ingredients list “sucralose” or Splenda in an undisclosed amount. Protein powders and Pre-Workout Supplements are known for including Sucralose and Acesulfame Potassium in unknown quantities per serving. In my kitchen, I found a salad dressing, a steak marinade, and children’s multivitamins that all contained alternative sweeteners listed among the ingredients.
Now, I’m not claiming that artificial sweetener is “bad” because nothing in nutrition is ever absolute. For many who consume large amounts of added refined sugar daily, switching to sugar alternatives may positively impact their health. I’m arguing that we live in a culture obsessed with wellness that places incredible pressure on individuals to make the “right” health choices. Marketing leads us to believe that labels like “Organic,” “Diet,” or “Sugar-Free” make those choices easier for us, when in fact, they may be damaging our gut microbiome.
So what? What do we do with this information? Few of us have the time, energy, money, and resources to outfit our kitchens with fresh ingredients daily. With 1 in 4 households experiencing food insecurity since the pandemic’s beginning, many families are limited in what food they can access. Food is an essential aspect of our cultures, history, and environments, all of which inform the types of food we consume. If you generally prefer the taste of Diet Coke, by all means, continue to drink it. When it comes to the impact on your microbiome, feel free to leave the “CarbSmart” ice cream in the freezer aisle and have a scoop of the real stuff.
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