Processed foods are suspected of causing a variety of heath issues.
Foods high in sugar and refined carbohydrates, for example, are known to
cause high blood sugar and obesity. But recent research has uncovered
an entirely new mechanism by which many metabolic disorders can be
triggered. Certain additives that are commonly used in processed foods
are being shown to impact health, at least in mice, by altering the
body’s population of bacteria that live in the gut. Collectively
referred to the microbiome, the importance of this bacterial community
of millions is just beginning to be understood.
Research published last September demonstrated that artificial sweeteners can
raise blood sugar levels
in mice, stimulate their appetites, and possibly lead to obesity and
diabetes. The artificial sweeteners appear to create these conditions by
changing the micriobiome’s composition.
Last month, a different set of
researchwas
published that also suggested a disease pathway mediated by microbiome
disturbance. This time, commonly used food additives called emulsifiers
are the culprits.
Emulsifiers
help keep sauces smooth and ice cream creamy, they hold dressings
together and prevent mayonnaise from separating into oil and water. The
new research gives reason to suspect that emulsifiers could raise your
blood sugar, make you fat and even make your butt hurt.
The study,
published in Nature, looked at two common emulsifiers, Polysorbate 80
and carboxymethylcellulose (CMC), and found a range of metabolic
problems that appeared in mice who were given water dosed with these
chemicals in quantities proportional to what a human might consume. The
mice who drank either emulsifier tended to eat more, gain weight and
develop conditions like irritable bowel syndrome, colitis and metabolic
syndrome, which is a range of pre-diabetic conditions.
The effects
of these additives were dependent on the dosage; the more emulsifier
the mice consumed, the worse off they were. A control group drank water
laced with a common preservative, sodium sulfite, and did not show any
negative effects on the gut.
The team found that the bacterial
diversity of the mice microbiomes were altered. They also discovered the
mucous membrane of the gut was thinner in mice who were fed
emulsifiers. The thinner mucous membrane allowed the microbes closer to
the gut wall than they would normally get, they wrote, which could cause
the observed inflammation of the gut wall, and diseases like irritable
bowel syndrome.
John Coupland, a professor of food science at Penn
State University, thinks this research could be a game changer,
providing it can be shown that these emulsifiers can do to humans what
they do to mice. “[It] really challenges a lot of the way we think about
assessing toxicology and nutritional value of foods,” he said in an
email.
Coupland noted that Polysorbate 80 and CMC are very
different molecules. While Polysorbate 80 is small, and doesn’t carry an
electrical charge, CMC is large, and charged. These molecules are not
only built differently, but they behave differently, he said, pointing
out that CMC is technically not even an emulsifier, but a thickener that
makes emulsions more stable. That they both cause similar microbial
disruptions, mucous reductions and associated health problems is a
striking discovery.
In an email interview, the study’s
co-author, Benoit Chassaing, acknowledged that CMC is more of a
thickener than an emulsifier, but noted that it does have emulsification
properties, due to its charge. He suspects the resulting emulsifying
activity is to blame.
I asked how they originally thought to look at emulsifiers. Chassaing explained:
"The
incidence of IBD and metabolic syndrome has been markedly increasing
since about the mid-20th century, and this dramatic increase has
occurred amidst constant human genetics, suggesting a pivotal role for
an environmental factor. We considered that any modern additions to the
food supply might play an important role, and addition of emulsifiers to
food seems to fit the time frame of increased incidence in these
diseases.
"We hypothesized that emulsifiers
might impact the gut microbiota to promote these inflammatory diseases
and designed experiments in mice to test this possibility."
The
team is currently investigating other common emulsifiers, aiming to
identify any others that might cause microbial disturbances, or
inflammation of the gut. Carrageenan, Chassaing noted, has
already been foundto
cause inflammatory bowel disease in rats. Extracted from seaweed,
carrageenan is widely used in processed “natural” foods. Like CMC,
carrageenan is more of a thickener than an emulsifier, but is, like CMC,
on the spectrum of additives that exhibit emulsifying properties.
One
molecule his team is currently investigating is lecithin, which is a
true emulsifier. Like carrageenan, lecithin is used in many “natural”
processed products. If lecithin shows similar activity to carrageenan,
CMC, and Polysorbate 80, it would cast a shadow over many, many
processed food formulations. Organic processed foods are still processed
foods. Organic approved additives like carrageenan can still give you
ulcerative colitis.
Food
additives are tested for certain toxilogical activities, like the
ability to cause cancer, or to cause a mouse to instantly drop dead. But
they aren’t tested for any potential effects they might have on one’s
microbiome, or their ability to stimulate one’s appetite, or cause
conditions like irritable bowel syndrome.
If the recent results on
mice can be repeated in humans, current testing protocols for food
additives will be revealed as woefully inadequate.
If you stay
away from highly refined, heavily processed foods with long lists of
ingredients, you can avoid most of these additives in one swoop, and not
have to worry about inadequate testing procedures.
But not
everyone has the luxury of being able to avoid processed foods,
especially the poor, and ironically, people stuck in institutions like
hospitals. That’s why we need the standards by which food additives are
evaluated to be updated sooner, rather than later.
