Soap Residue and Gut Health
Soap residue left on dishware by restaurant dishwashers could harm gut health.
When eating out at a restaurant, you assume you’re eating off of a squeaky-clean plate. However, your gut may beg to differ. A study from Swedish immunologists using human intestinal organoids and intestinal cells on microchips found that commercial dishwashers, common in many restaurants, can leave behind a chemical soap residue from a rinsing agent that’s potentially harmful to the gastrointestinal tract.
The researchers believe the chemical soap residue can weaken the epithelial barrier in the gut—a layer of cells bordering the intestinal tract that controls what enters the body—and thereby set the stage for a leaky gut barrier and subsequently several health disorders. The research team diluted the substance found in commercial detergents and rinse aids, to resemble levels that would be left behind on dry dishes, before exposing them to intestinal cells. But it’s not known how much exposure to these chemicals is required to have an impact, or in other words, how often someone needs to eat out to put their gut health at risk. The findings appear in The Journal of Allergy and Clinical Immunology.
Matthew Kadey, MS, RD, is a James Beard Award–winning food journalist, dietitian and author of the cookbook Rocket Fuel: Power-Packed Food for Sport + Adventure (VeloPress 2016). He has written for dozens of magazines, including Runner’s World, Men’s Health, Shape, Men’s Fitness and Muscle and Fitness.