Preventive Medicine Column

Dr. David L. Katz

Gluten is a protein, found predominantly in the seeds of various grasses.  We typically refer to the edible seeds of grasses as grains. Gluten is found in the endosperm, the principal part of the grain retained when grains are refined (and generally considered the least nutritious component).  Consequently, gluten is present in grains such as wheat, rye, and barley- whether or not they are “whole.”

The most significant health problem associated with gluten consumption is, technically, gluten-sensitive enteropathy, long known as celiac disease, celiac sprue, or non-tropical sprue.  In this condition, the immune system mounts a response to gluten as if it were a dangerous invader, such as a germ.  The resulting inflammation damages the intestinal lining, leading to malabsorption of   diverse nutrients, including both vitamins and minerals.  Adverse effects can be severe, ranging from abdominal discomfort, to the manifestations of nutrient deficiencies, to an itchy rash, and over time, increased risk of intestinal cancer.  Unaddressed, the condition can be lethal.

Along with celiac disease, there is also the milder “gluten sensitivity.”  This term is something of a catch-all, likely referring to various forms of intolerance and true allergy to gluten.  The distinction between such conditions and celiac disease is that measurable antibodies to gluten are absent, as is observable damage to the lining and architecture of the intestine.  Also absent is the nutrient malabsorption, and increased risk of cancer.  Recent insights, however, suggest the two conditions may overlap more than previously thought with regard to diverse symptoms.

There is good reason for gluten to loom large in current health lore: the numbers adversely affected by it are rising.  To some extent, this is a product of something called “detection bias.”  The more aware, and concerned, the health care community is about any given health condition, the more we look for it.  The more one looks for any given condition, the more one tends to find it.  In contrast, you don’t tend to detect what you don’t consider.

Health professionals’ sensitivity to gluten sensitivity accounts for some portion of the rising prevalence, but certainly not all.  Studies based on blood kept in storage clearly indicate that actual rates of celiac disease have risen over recent decades, as much as four-old in the past half century.

In some cases, genetic modifications have increased the gluten content of wheat and other grains.  It may be that genetic modifications are also introducing new nutrients into the diet, and some reactions to gluten may be primed by the company it is keeping.

There may also be an influence of nutrient combinations due to modern food processing.  Gluten is a widely used texturizer.  That it is found in wheat, barley, rye, triticale, and possibly oat-containing products is expected.  That it is found in everything from candy, to deli meats, to potato chips may be less so.  Its use in all these foods is producing novel nutrient pairings, and perhaps these also function at times as an immune system trigger.

In the US today, celiac disease is far from rare- affecting roughly 1% of the population at large.  Gluten sensitivity affects 5 to 10 times as many.  Celiac disease can be diagnosed by blood tests, biopsies, or both.  The only truly reliable test for gluten sensitivity is a trial elimination of gluten to determine if symptoms wax and wane its intake.

Prevalent as it is, gluten sensitivity still only affects a minority in the general population- but gluten preoccupation appears to affect many more.  The potential adverse health effects of gluten in those sensitive to it have reverberated in cyberspace, creating the impression that gluten is a bona fide toxin, harmful to all.  Gluten is not ‘bad’ for those tolerant of it, any more than peanuts are ‘bad’ for people free of peanut allergy.

Also abounding are home-grown theories about health effects of gluten- including the argument that going gluten free leads to weight loss.  It might, but only because avoiding gluten means avoiding a lot of foods, which in turn tends to mean reducing calories intake.

Going gluten free is easier than it once was- due to better food labeling, more gluten-free products, and ever better guidance in-print and on-line.  But it is still quite hard, given the widespread use of gluten in packaged foods, under a wide variety of aliases.  The effort is well-justified for those who are truly gluten-sensitive.

For everyone else, going gluten free is at best a fashion statement, and at worst unnecessary dietary restriction that results in folly.  It reflects a tendency to ingest the ever proliferating pop-culture perspectives on diet and health, without first separating wheat from chaff.




Dr. David L. Katz;