WASHINGTON Feb 25 Common additives in ice
cream, margarine, packaged bread and many processed foods may
promote the inflammatory bowel diseases ulcerative colitis and
Crohn's disease as well as a group of obesity-related
conditions, scientists said on Wednesday.
The researchers focused on emulsifiers, chemicals added to
many food products to improve texture and extend shelf life. In
mouse experiments, they found emulsifiers can change the species
composition of gut bacteria and induce intestinal inflammation.
Such inflammation is associated with the frequently
debilitating Crohn's disease and ulcerative colitis as well as
metabolic syndrome, a group of conditions that increase risk for
type-2 diabetes, heart disease and stroke.
Mice were fed emulsifiers diluted in drinking water or added
into food, which were found to trigger low-grade intestinal
inflammation and features of metabolic syndrome such as blood
glucose level abnormalities, increased body weight and abdominal
Consuming emulsifiers increased the risk of colitis,
mimicking human inflammatory bowel disease, in mice genetically
susceptible to the condition, the study found.
Georgia State University microbiologist Benoit Chassaing,
whose study appears in the journal Nature, said the effects seen
in mice "may be observed in humans as well."
The study involved two widely used emulsifiers, polysorbate
80 and carboxymethylcellulose. The researchers are planning
human studies and are already studying other emulsifiers.
Emulsifiers are used in margarine, mayonnaise, creamy
sauces, candy, ice cream, packaged processed foods and baked
goods. They can make products like mayonnaise smooth and creamy
instead of an unappetizing amalgam of water and oily globules.
A key feature of inflammatory bowel diseases and metabolic
syndrome is a change in the gut microbiota - the roughly 100
trillion bacteria that inhabit the intestinal tract - in ways
that promote inflammation. In mice given emulsifiers, the
bacteria were more apt to digest and infiltrate the dense mucus
layer that lines and protects the intestines.
Incidence of inflammatory bowel disease and metabolic
syndrome started rising in the mid-20th century at roughly the
same time that food manufacturers began widespread emulsifier
use, the researchers said.
"We were thinking there was some non-genetic factor out
there, some environmental factor, that would be explaining the
increase in these chronic inflammatory diseases," Georgia State
immunologist Andrew Gewirtz said.
"And we thought that emulsifiers were a good candidate
because they are so ubiquitous and their use has roughly
paralleled the increase in these diseases. But I guess we were
surprised at how strong the effects were."
(Reporting by Will Dunham; Editing by Leslie Adler)