Celiac
disease and the idea of gluten-free diets were merely a blip on the radar 20
years ago. However, in the United
States and across the world more individuals are being diagnosed with celiac
disease, and more consumers are embracing the idea of a gluten-free diet
(GFD)(1). Researching a topic is
always more interesting when a personal interest regarding the topic
exists. My mother discovered 4
years ago that she was gluten sensitive, and I have been learning bits and
pieces about gluten ever since. As
a student of nutrition and an employee of a gluten-free food company, I felt it
was my duty to learn as much as I could about gluten. The following is a brief summary of my findings based upon
current scientific research regarding gluten.
Gluten
is a structural protein that is found in wheat, rye, and barley. Oats do not contain gluten, but most
commercially produced oats contain trace amounts of gluten unless otherwise
noted on the package. Human
exposure to gluten containing grains took rise around 10,000 years ago as agriculture
began to develop. Gluten is widely
used in food processing, and it has been long prized for the desirable
characteristics it lends to breads and doughs. In the United States, gluten is most commonly found in
bread, baked goods, pasta, cereal, and snack foods (1).
Gluten
has become increasingly popular in the media, and those following GFDs have
also steadily increased. In 2010,
global sales of gluten-free products totaled nearly $2.5 billion dollars
(1). In addition to this, the
occurrence of undiagnosed celiac disease in the United States is approximately
4 times greater than 50 years ago (2). It is estimated that around 1% of the population in
the United States could have celiac disease (3), and 1% of the population would
equal more than 3 million people (4).
In addition to developing scientific research, the increased number of
those with celiac disease and gluten sensitivity/intolerance makes gluten
something worth investigating.
Celiac
disease has long been the health issue related to gluten. Celiac disease is an inflammatory
disorder of the small intestine that occurs from the ingestion of gluten
containing foods (5). Celiac
disease is heavily genetic and may also be dependent on other environmental
factors. Celiac disease is
typically diagnosed by blood tests that detect the presence of antibodies to
gliadin (a component of gluten). If
an individual tests positive, a biopsy of the small intestine is normally taken
to give a definitive diagnosis of having celiac disease. Those most susceptible to celiac
disease are Caucasians, especially those with northern European ancestry
(5). Women are also twice as
likely as men to be diagnosed with celiac disease (6).
If
gastrointestinal distress exists, a physician will often suggest an exclusion
diet. In an exclusion diet, a food
that is normally eaten is removed from the diet to see if symptoms improve with
its removal. This is commonly done
with gluten and dairy at the same time until symptoms subside, and then one or
the other is added back in to the diet to see if it is the culprit. Celiac disease is dangerous because the
ingestion of gluten causes damage to villi in the small intestine. The villi are like little fingers that
reach out to grab nutrients, and their presence helps increase the absorptive
area of the intestine. Untreated
celiac disease will damage the villi (causing the surface to flatten), and
individuals may suffer from serious malabsorption and malnutrition (5).
An example of celiac disease related intestine damage (5)
In
the past, you were either celiac or you were not, and the idea of gluten
sensitivity or intolerance was not widely accepted. Some people have similar gastrointestinal symptoms as those
with celiac disease, but they do not test positive for celiac disease. A recent study fed individuals
suffering from irritable bowel syndrome (IBS) a gluten-free diet. Those consuming a gluten-free diet
experienced less gastrointestinal problems compared to those who continued to
consume gluten. This study shows
that some people who are suffering from bowel problems may feel better by
removing gluten from their diet.
The mechanism of how removing gluten from the diet is beneficial for
those without celiac disease is not completely understood, but this opens the
door to the possibility that multiple types and levels of gluten intolerance
may exist (7).
Recently,
gluten has begun to be associated with more than just celiac disease. Gluten increases the permeability of
the gut, and it appears that this increases the chance of autoimmune disorders
in gluten-sensitive individuals (8).
Autoimmune diseases that may be linked to gluten include type 1 diabetes
and thyroid disease (9). Another
gluten-related health issue is dermatitis herpetiformis, a skin rash that is
resolved by eating a GFD. Gluten
ataxia, a fairly uncommon neurological disorder, is where the cerebellum is
damaged by gluten anti-bodies.
This leads to motor skill issues, and removing gluten from the diet
typically stops the progression of the condition but does not repair what has
been damaged. Individuals who have
celiac disease are at greater risk for these autoimmune diseases and gluten-related
health problems (9). Recently, the
media has tried to pinpoint gluten as a possible cause of autism, but there
currently are not any studies supporting this claim (5).
Although
gluten may seem like the bad guy, one must remember that only a portion of the
general public is negatively affected by gluten. Increasing scientific research is tying gluten to other
health issues, but the science is far from condemning gluten altogether. This information is provided to give a
general overview of gluten and to show why some may be consuming a gluten-free
diet. However, one should consider
getting tested if they have a family history of celiac disease or gluten
intolerance. Many are still unsure
about gluten, but more scientific research that is being done will offer
insight into how it may or may not be affecting our health.
References
1.
Sapone A, Bai JC, Ciacci C, et al. Spectrum of gluten-related disorders:
Consensus on new nomenclature and classification. BMC Med. 2012:10(13);1-12.
2.
Rubio-Tapia A, Kyle RA, Kaplan EL, et al. Increased prevalence and
mortality in undiagnosed celiac disease. Gastroenterol. 2009:137(1);88-93.
3.
Questions and answers on the gluten-free labeling proposed rule. US Food
and Drug Administration. http://www.fda.gov/food/labelingnutrition/foodallergenslabeling/
guidancecomplianceregulatoryinformation/ucm111487.htm.
May 14, 2012. Accessed November
23, 2012.
4.
U.S. & world population clocks. United States Census Bureau. http://www.census.gov/main/www/popclock.html.
December 3, 2012. Accessed
December 3, 2012.
5. Di Sabatino A, Corazza GR. Coeliac disease. Lancet. 2009:373(9673);1480-1493.
6.
Megiorni F, Mora B, Bonamico M, et al. HLF-DQ and susceptibility to
celiac disease: Evidence for gender differences and parent-of-origin effects. Am J Gastroenterol. 2008:103;997-1003.
7.
Biesiekierski JR, Sci BA, Newnham ED, et al. Gluten causes
gastrointestinal symptoms in subjects without celiac disease: A double-blind
randomized placebo-controlled trial. Am J
Gastroenterol. 2011:Advance online publication.
8.
Visser J, Rozing J, Sapone A, Lammers K, Fasano A. Tight junctions,
intestinal permeability, and autoimmunity. NY
Acad Sci. 2009:1165;195-205.
9.
Troncone R, Jabri B. Coeliac disease and gluten sensitivity. J Int Med. 2011:269;582-590.
