An emulsifier is a substance that helps two other substances mix together and stay mixed (think salad dressing, for example). They go by names such as polysorbate 80, lecithin and carrageenan and their purpose is to improve the shelf life of many of our foods, such as ice cream and baked goods. The downside of these additives is that research is indicating that emulsifiers may be contributing to the increase in obesity and inflammatory bowel disease (Chassaing et al., 2015).
In a recent Georgia State University experiment, researchers fed mice emulsifiers through their food and water. They found that these food additives changed the bacteria in the mice in a way that caused chronic inflammation in their guts. The mice with abnormal immune systems developed chronic colitis. Those with normal immune systems developed mild intestinal inflammation and a metabolic disorder that caused them to eat more and become more obese, hyperglycemic and insulin resistant.
This is not the first time that emulsifiers have been implicated in digestive disorders. The rates of Crohn's disease (CD) have increased over the past 50 years. Roberts (2013) suggested that consumption of emulsifiers in processed foods may promote the disease by changing the location of the bacteria in the gut. One piece of evidence that may be important is that the geographic location of those with CD correlates with places where emulsifiers are consumed. While correlation does not make causation, this relationship may serve as one more piece of understanding the puzzle.
Emulsifiers are approved by the Food and Drug Administration. However, some now believe that the current protocols for assessing their safety in our food may be inadequate (Bordon, 2015) and need to be reconsidered in light of the recent research. In the meantime, if you are living with an inflammatory digestive disease, it may be a good idea to limit the amount of processed food you are consuming.