Ultraprocessed foods are food products that have been altered, usually in order to extend shelf life and/or make them more palatable. This is accomplished through multiple rounds of processing, as well as the use of additives such as artificial colors, flavors, and preservatives, among other substances. Some products that fit into this category are soft drinks, snack foods, frozen food, chips, etc. These foods often contain extra ingredients such as chemical additives, modified starches, and added oils, as described here. Ultraprocessed foods not only contain these added ingredients, but they also often have an overall lack of nutritional value due to a lack of vitamins, minerals, etc.
Some additives, described here, are particularly common in a wide variety of foods. Emulsifiers are added to foods like ice cream, chocolate, and mayonnaise to keep ingredients mixed and to give them a smooth texture. Artificial sweeteners are often used in diet sodas, yogurts, or protein powders to provide sweetness while not including sugar. Preservatives are included in things such as packaged breads, canned goods, or processed meats to slow spoilage and extend shelf life. To make products more appealing, colorants like Red 40 give foods a consistent look, while flavor enhancers like MSG intensify taste in snacks, soups, and instant noodles. Together, these additives help processed foods stay stable, look attractive, and taste the same every time you buy them.
Photo by Evan-Amos
Short-chain fatty acids (SCFAs) are important byproducts of gut microbial fermentation, and recent human research shows that emulsifiers can lower their production. In a double-blind randomized trial, healthy adults first consumed an emulsifier-free diet and then were given brownies containing one of several emulsifiers, such as carboxymethyl cellulose, soy lecithin, etc. Across the groups, SCFA levels dropped compared to placebo, most strongly in the carboxymethyl cellulose group, suggesting a negative impact on microbial metabolism. Overall, microbial diversity did not change much, but their function was impaired. This finding highlights that emulsifiers can alter microbes’ ability to function in their common role, even when the number of species remains stable.
The same study also looked at how these additives shift gut microbial composition. While it didn’t report major across-the-board decreases in Bifidobacterium or Faecalibacterium, earlier studies have shown that these beneficial taxa can be reduced by emulsifier exposure. Because both genera are known for producing butyrate and supporting anti-inflammatory processes in the gut, even small changes in their activity could explain the lower SCFA levels found in participants. The trial’s results suggest emulsifiers may quietly weaken beneficial microbial functions without causing dramatic changes in overall diversity. All of this data goes to show how ultra-processed food additives can negatively impact gut health.
Image by Lee et al
Research suggests that consuming ultra-processed foods (UPFs) may increase both the risk and severity of multiple sclerosis (MS). A study found that each extra daily serving of UPFs was linked to a higher chance of central nervous system demyelination, and higher overall intake was associated with nearly triple the odds of moderate-to-high MS severity. UPFs typically contain refined sugars, saturated fats, trans fats, and high levels of salt, which can promote inflammation and disrupt the balance of gut bacteria. This imbalance may reduce the production of SCFAs and increase intestinal permeability, contributing to systemic inflammation and immune system dysregulation. Overall, these factors suggest that diet plays a significant role in MS development and progression.
Focusing on whole-food diets may help mitigate the negative effects of UPFs on MS. Diets rich in fruits, vegetables, whole grains, and healthy fats support gut health and reduce inflammation. Maintaining a diverse and balanced gut microbiota helps preserve SCFA production, which is important for regulating immune responses. Limiting UPFs can also reduce activation of pro-inflammatory T helper cells, which are implicated in the onset of MS. In summary, replacing ultra-processed foods with nutrient-dense whole foods could be a practical approach to managing MS risk and symptoms.
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